Review of the comparative pathological and immunohistochemical features of human and canine cutaneous melanocytic neoplasms.

Melanocytic neoplasms originate from melanocytes and melanoma, the malignant form, is a common canine neoplasm and the most aggressive human skin cancer. Despite many similarities between these neoplasms in both species, only a limited number of studies have approached these entities in a comparative manner. Therefore, this review compares benign and malignant melanocytic neoplasms in dogs and humans, exclusively those arising in the haired skin, with regard to their clinicopathological, immunohistochemical and molecular aspects. Shared features include spontaneous occurrence, macroscopic features and microscopic findings when comparing human skin melanoma in the advanced/invasive stage and canine cutaneous melanoma, immunohistochemical markers and several histopathological prognostic factors. Differences include the apparent absence of active mutations in the BRAF gene in canine cutaneous melanoma and less aggressive clinical behaviour in dogs than in humans. Further studies are required to elucidate the aetiology and genetic development pathways of canine cutaneous melanocytic neoplasms. Evaluation of the applicability of histopathological prognostic parameters commonly used in humans for dogs are also needed. The similarities between the species and the recent findings regarding genetic mutations in canine cutaneous melanomas suggest the potential utility of dogs as a natural model for human melanomas that are not related to ultraviolet radiation.

Atypical Presentation of Spitz Nevus: A Case Report.

Introduction: The Spitz nevus (SN) is an acquired melanocytic neoplasm composed of epithelioid and/or spindle cells, which tends to develop in childhood. In pediatric patients, it is usually located on the face and neck. Unusual locations have been found in the literature, such as the penis, mouth, and tongue, as well as 2 cases of ungual SN. Case Report: A 15-year-old male evaluated for dark brown-black longitudinal melanonychia that covered 40% of the nail, with pseudo-Hutchinson's sign, of 1 year of evolution. Discussion: The SN accounts for 1% of the melanocytic neoplasms. In the present paper, we show the third case of ungual SN never previously disclosed, which presents a zigzag pattern reported in the literature for its association with the pediatric population.

Carcinoma de células escamosas em gato - tratamento com quimioterapia metronômica / Squamous cell carcinoma in a cat - treatment with metronomic chemotherapy

Background: Squamous cell carcinoma (SCC) is a malignant neoplasm associated with prolonged exposure to ultraviolet light and lack of skin pigment in white-coated animals. The disease diagnosis is based on the animal's history, clinical signs and histopathology of the samples collected. The therapeutic alternatives are diverse. Among them, one of the most used is the metronomic chemotherapy which is based on the use of cytostatics drugs, applied in low and frequent doses for a longer period of time. One of the mechanisms of action of this type of therapy is the decrease in angiogenesis. Non-steroidal anti-inflammatory drugs (NSAIDs) are simultaneously used to maximize the angiogenic effect. The objective of this study is to report the results of a treatment accomplised with metronomic chemotherapy (cyclophosphamide with meloxicam) in a domestic feline which presented a squamous cell tumor. Case: A 7-year-old female cat, mixed breed, not neutered, weighing 3.5 kg, was assisted at the Veterinary Specialties Teaching Clinic (CEEV) of the Technical University of Machala (UTMACH), presenting bilateral ulcerative lesion in the nasal plane for 5 months. Chronic exposure to sunlight is referred to in the patient's anamnesis. Aspiration cytology performed in the patient revealed an inflammatory process with a predominance of neutrophils and macrophages, and showed absence of neoplastic cells. A treatment based on antibiotics and corticosteroids was adopted. As there were no favorable results, an excisional biopsy procedure was chosen to collect the affected tissues. The result of the histopathological analysis was a level 2 squamous cell carcinoma (SCC). The initial treatment consisted of surgical removal of the tumor and later the use of metronomic chemotherapy based on Cyclophosphamide, Meloxicam, DHA (docosahexaenoic acid) and Sucralfate for 5 months was adopted. At the beginning of the second phase of treatment, the patient developed a macula that progressively diminished. Currently, the patient does not have any recurrence of the diagnosed neoplasm. Discussion: The diagnosis of squamous cell carcinoma was based on clinical and histopathological findings. The macroscopic lesions were crusted ulcers that do not heal in the nasal plane and auricular pavilion, as reported in the literature. SCC is characterized by the infiltration of squamous cells in the dermal layer of the skin, forming epithelial islands with keratin pearls. The histopathological findings of this case present the same characteristics. The climatic conditions of Ecuador, high temperatures with greater incidence of sunlight, hypopigmented areas of the animal's body and chronic exposure to solar radiation are risk factors present in this case that foster the development of this malignant neoplasm. There are multiple treatments to be introduced in this sort of pathology. In this case, surgical removal of the tumor was adopted, followed by metronomic chemotherapy based on cyclophosphamide at 10 mg/m2 and meloxicam at a 0.05 mg/kg per day for a period of time of five months, obtaining favorable results and absence of recurrence. Despite metronomic chemotherapy being easy to administer, with fewer side effects, which includes a better acceptance of care takers who are reluctant to administer conventional chemotherapy, further studies are still necessary in what concerns certain variables such as age, carcinoma level, appropriate dosages and drugs according to each neoplasm.

Mastocitoma cutâneo canino após mastocitose acidental induzida por opioide: Relato de caso / Canine cutaneous mastocytoma after accidental opioid-induced mastocytosis: Case report

A aproximação entre petse tutores está cada vez mais presente na rotina atual das residências familiares. Essa aproximação aumenta a observação de quaisquer alterações físicas ou comportamentais dos animais levando-o a buscar um médico veterinário quando necessário. O papel do clínico, oncologista e do patologista veterinário vem a ser de extrema importância para detecção das neoplasias em suas fases iniciais. A utilização dos meios de diagnósticos complementares para os casos de neoplasias é de fundamental importância para ter ciência do prognóstico do animal e de qual tratamento será o melhor tratamento para os casos abordados. O mastocitoma é a neoplasia cutânea mais frequente do cão, é uma neoplasia maligna e sua etiologia é pouco compreendida. Independente do sexo, atingem machos e fêmeas, porém se apresentam de forma mais agressiva em machos. O diagnóstico, geralmente é estabelecido por meio de exames complementares, associados aos sinaisclínicos, devendo sempre prezar pelo diagnóstico precoce para que haja maior êxito no tratamento.O exame citológico para o diagnóstico de mastocitoma é um dos métodos mais eficientes e de baixo custo, sendo complementado pelo exame histopatológico para agraduação de malignidade e estadiamento da doença. Preconiza-se a associação da cirurgia com o tratamento quimioterápico com terapia antiblástica e eletroquimioterapia para um melhor prognóstico. O objetivo deste trabalho foi relatar um caso de mastocitoma cutâneo após um erro primário de manejo clinico, em um canino, macho, nove anos, da raça American Pitbull Terrier, trazendo sua complexidade e bases dos meios de diagnóstico(AU)

The approximation between pets and tutors is increasingly present in the current routine of family homes. This approach increases the observation of physical or behavioral changes in animals, leading them to seek a veterinarian when necessary. The role of the clinician, oncologist and veterinary pathologist is extremely important for the detection of neoplasms in their early stages. The use of complementary diagnostic means for cases of neoplasms is of fundamental importance to be aware of the animal's prognosis and which treatment will be the best treatment for the cases examined. Mastocytoma is the most frequent skin neoplasm in dogs, it is a malignant neoplasm and its etiology is poorly understood. Regardless of gender, they affect males and females, but are more aggressive in males. The diagnosis is usually established through complementary exams, associated with clinical signs. Cytological examination for the diagnosis of mast cell tumor is an inexpensive method and one of the most efficient methods, being complemented by histopathological examination for its evolution of malignancy and disease staging, recommended the association of surgery with chemotherapy treatment with antiblastic therapy and electrochemotherapy for better prognoses. The aim of this study was to report a case of cutaneous mastocytoma after a primary error in clinical management, in a canine, male, nine years old, of the American Pitbull Terrier breed, bringing its complexity and bases of the means of diagnosis(AU)

Tricoblastoma em canino doméstico / Trichoblastoma in a domestic canine

A pele é um órgão complexo constituído por diferentes tipos celulares e possui exposição direta ao meio ambiente, representando uma barreira física do organismo. Devido a tais fatores pode ocorrer o aparecimento de diversos tipos tumorais. Além disso, a pele possui alta capacidade de renovação celular, o que aumenta as chances de mutações em comparação com outros tecidos, o que a torna um lugar favorável para o desenvolvimento de neoplasias. É comum ocorrer nos animais domésticos o desenvolvimento de neoplasias cutâneas, sendo que sua prevalência depende de fatores como genética, idade, raça, relação hormonal, nutrição, entre outros. O tricoblastoma é uma neoplasia benigna cutânea comum em cães e gatos adultos, animais com idade entre seis e nove anos são os mais acometidos, e não existe predisposição em machos e fêmeas. É derivado do folículo piloso primitivo e possui componentes epiteliais e mesenquimais. O tricoblastoma não é considerado agressivo, porém, existem relatos na literatura com características de neoplasia maligna. O tratamento de eleição do tricoblastoma é a exérese cirúrgica total do mesmo, com margens de segurança entre 1 e 2cm. O presente estudo tem como objetivo relatar o caso de um animal atendido no Centro Médico Veterinário do Centro Universitário do Sul de Minas, o qual foi diagnosticado com tricoblastoma.

The skin is a complex organ composed of different cell types and has direct exposure to the environment, representing an organism's physical barrier. Due to such factors, the appearance of several tumor types may occur. In addition, the skin has a high capacity to perform cell renewal, which increases the chances of mutations compared to other tissues, turning it a favorable place for the development of neoplasms. The development of skin neoplasms in domestic animals is a common fact, and their prevalence depends on factors such as genetics, age, race, hormonal relationship, nutrition, among others. Trichoblastoma is a benign cutaneous neoplasm common in adult dogs and cats, animals aged between six and nine years are the most affected, and there is no predisposition in males and females. It is derived from the primitive hair follicle and has epithelial and mesenchymal components. Trichoblastoma is not considered aggressive; however, there are reports in the literature with characteristics of malignant neoplasm. The treatment of choice for trichoblastoma is the total surgical excision, with safety margins between 1 and 2cm. The present study aims to report the case of an animal treated at the Veterinary Medical Center of the University Center of Southern Minas Gerais, which was diagnosed with trichoblastoma.

The skin through reflectance confocal microscopy -Historical background, technical principles, and its correlation with histopathology

Abstract Since its first introduction into medical practice, reflectance confocal microscopy (RCM) has been a valuable non-invasive diagnostic tool for the assessment of benign and malignant neoplasms of the skin. It has also been used as an adjunct for diagnosing equivocal cutaneous neoplasms that lack characteristic clinical or dermoscopic features. The use of RCM has led to a decreased number of biopsies of benign lesions. Multiple published studies show a strong correlation between RCM and histopathology thereby creating a bridge between clinical aspects, dermoscopy, and histopathology. Dermatopathologists may potentially play an important role in the interpretation of confocal images, by their ability to correlate histopathologic findings. RCM has also been shown to be an important adjunct to delineating tumoral margins during surgery, as well as for monitoring the non-surgical treatment of skin cancers. Advanced technology with smaller probes, such as the VivaScope 3000, has allowed access to lesions in previously inaccessible anatomic locations. This review explains the technical principles of RCM and describes the most common RCM features of normal skin with their corresponding histological correlation.

The skin through reflectance confocal microscopy - Historical background, technical principles, and its correlation with histopathology.

Since its first introduction into medical practice, reflectance confocal microscopy (RCM) has been a valuable non-invasive diagnostic tool for the assessment of benign and malignant neoplasms of the skin. It has also been used as an adjunct for diagnosing equivocal cutaneous neoplasms that lack characteristic clinical or dermoscopic features. The use of RCM has led to a decreased number of biopsies of benign lesions. Multiple published studies show a strong correlation between RCM and histopathology thereby creating a bridge between clinical aspects, dermoscopy, and histopathology. Dermatopathologists may potentially play an important role in the interpretation of confocal images, by their ability to correlate histopathologic findings. RCM has also been shown to be an important adjunct to delineating tumoral margins during surgery, as well as for monitoring the non-surgical treatment of skin cancers. Advanced technology with smaller probes, such as the VivaScope 3000, has allowed access to lesions in previously inaccessible anatomic locations. This review explains the technical principles of RCM and describes the most common RCM features of normal skin with their corresponding histological correlation.

Perfil epidemiológico dos laudos histopatológicos de carcinoma basocelular realizados nos laboratórios de Patologia da região sul-catarinense / Epidemiological profile of histopathological reports of basal cell carcinoma performed in pathology laboratories in southern Santa Catarina, Brazil

Introdução: O carcinoma basocelular é a neoplasia mais comum no mundo. É responsável, juntamente com os demais cânceres de pele, pelo grande aumento dos gastos públicos, quando comparados aos demais tipos de câncer. Este estudo teve como objetivo avaliar o perfil epidemiológico dos laudos histopatológicos de Carcinoma Basocelular (CBC) realizados nos laboratórios de Patologia da cidade de Criciúma/ SC. Métodos: Foi feito um estudo observacional retrospectivo, com coleta de dados secundários e abordagem quantitativa. Foram incluídos no estudo 301 laudos histopatológicos de CBC. Resultados: A média da idade no momento do diagnóstico foi de 64,09 anos. O gênero mais acometido foi o feminino, correspondendo a 55,5% dos laudos da amostra. Dos subtipos histopatológicos, o nodular foi o prevalente (52,2%), seguido pelo esclerodermiforme/infiltrativo (28,2%), superficial (11,3%), micronodular (5,6%), basoescamoso (1,7%) e pigmentado (1,0%). A localização cutânea de maior frequência foi cabeça e pescoço (67,4%), tendo o nariz como principal local das lesões (32,4%). Limitações do estudo: Este estudo teve como limitação a não informação da localização cutânea do CBC em 126 laudos. Conclusão: O CBC é mais comum em indivíduos a partir da sexta década de vida (p=0,017), preferencialmente em mulheres (p=0,013). O subtipo mais encontrado é o nodular seguido do esclerodermiforme. O nariz foi o local de maior acometimento das lesões. O subtipo superficial predominou no sexo feminino (p=0,013). Quanto à sua localização cutânea, o subtipo superficial está associado aos membros superiores e inferiores (p=0,037).

Introduction: Basal cell carcinoma is the most common neoplasm in the world. Along with other skin cancers, it is responsible for a large increase in public spending compared to other types of cancer. This study aimed to evaluate the epidemiological profile of histopathological reports of basal cell carcinoma performed in pathology laboratories in the city of Criciúma, SC, Brazil. Methods: This retrospective observational study was conducted using secondary data and a quantitative approach. A total of 301 histopathological reports of basal cell carcinoma were included. Results: The mean age at diagnosis was 64.09 years, with women being more affected (55.5%). Of the histopathological subtypes, nodular was the most prevalent (52.2%), followed by infiltrative (28.2%), superficial (11.3%), micronodular (5.6%), basosquamous (1.7%) and pigmented (1.0%). The most frequent location was the head and neck (67.4%), with the nose being the main site of lesions (32.4%). Study limitations: The carcinoma location was missing in 126 reports. Conclusion: basal cell carcinoma was more common in individuals ≥ 60 years of age (p=0.017), especially women (p=0.013). The most common subtypes were nodular and infiltrative. The nose was the most affected site. The superficial subtype predominated in women (p=0.013). The superficial subtype was associated with the upper and lower limbs (p=0.037).

Carcinoma de células basales en la región vulvar: revisión bibliográfica a propósito de un caso / Vulvar basal cell carcinoma: A case report and review of the literature

Resumen ANTECEDENTES: El carcinoma de células basales, o basocelular, es la neoplasia cutánea no melanocítica más frecuente en la raza caucásica. La mayor parte de estas neoplasias aparecen en la piel fotoexpuesta (casi el 85% en la cabeza y el cuello). La afectación vulvar tiene una frecuencia no mayor al 1 al 2% de todos los carcinomas basocelulares. OBJETIVO: Reportar un caso de carcinoma basocelular de localización vulvar y revisar la bibliografía de los últimos siete años. CASO CLÍNICO: Paciente de 74 años, sin antecedentes personales de interés, con una lesión vulvar asintomática, con varios meses de evolución. En la exploración genital se encontró, en el labio mayor izquierdo, una lesión de 3 cm, pálida, no ulcerada, sobreelevada y pétrea. La biopsia de la lesión reportó: tejido mamario accesorio. Ante este informe se decidió la exéresis de la lesión y dejar un margen quirúrgico aproximado de 1 cm. La intervención y el posoperatorio transcurrieron sin contratiempos. El estudio anatomopatológico de la pieza quirúrgica reportó que se trataba de un carcinoma ulcerado de células basales, nodular y superficial, con los bordes de resección libres. En el seguimiento posquirúrgico a los dos meses, la paciente se encontró en buenas condiciones, asintomática. CONCLUSIONES: Si bien el carcinoma basocelular es una neoplasia muy frecuente, la afectación vulvar es por demás rara. El diagnóstico y el tratamiento deben ser interdisciplinarios, de la mano de dermatólogos y gineco-oncólogos.

Abstract BACKGROUND: Basal cell carcinoma, or basal cell carcinoma, is the most common nonmelanocytic skin neoplasm in Caucasians. Most of these neoplasms occur on photo exposed skin (almost 85% on the head and neck). Vulvar involvement has a frequency of no more than 1% to 2% of all basal cell carcinomas. OBJECTIVE: To report a case of basal cell carcinoma of vulvar location and to review the literature of recent years. CLINICAL CASE: 74-year-old patient, with no personal history of interest, with an asymptomatic vulvar lesion, with several months of evolution. On genital examination, a 3 cm lesion was found on the left labium majus, pale, non-ulcerated, raised, and stony. The biopsy of the lesion reported: accessory breast tissue. In view of this report, it was decided to excise the lesion and leave a surgical margin of approximately 1 cm. The operation and postoperative period went smoothly. The anatomopathological study of the surgical specimen reported that it was an ulcerated basal cell carcinoma, nodular and superficial, with free resection margins. At two months post-surgical follow-up, the patient was found to be in good condition, asymptomatic. CONCLUSIONS: Although basal cell carcinoma is a very frequent neoplasm, vulvar involvement is very rare. Diagnosis and treatment should be interdisciplinary, with the collaboration of dermatologists and gyneco-oncologists.

Breast carcinoma or sweat gland carcinoma? A report of two cases and a comparison with the literature / ¿Carcinoma de mama o carcinoma de glándula sudorípara? Presentación de dos casos y análisis de la literatura.

Primary apocrine carcinoma of the sweat gland is a neoplasm with a very low incidence that may represent a clinical and histological diagnostic challenge, as well as for adequate local, adjuvant, and advanced disease management. The average age of patients is around 67 years with no gender preference. This cancer develops primarily at the axillary and scalp levels and is clinically characterized by slow growth, but can progress aggressively with local, nodal, and metastatic involvement (primarily lung, liver, and bone). The recommended management, once the histology is established, consists of a wide local resection with a clear margin of 1 to 2 cm and regional lymphadenectomy if clinically positive nodes are detected. The adjuvant treatment (radiotherapy or chemotherapy) and for the advanced disease is not established. We report here the cases of two female patients initially diagnosed with breast cancer who were finally diagnosed with apocrine carcinoma of the sweat gland.

El carcinoma apocrino primario de glándula sudorípara es una neoplasia con una muy baja incidencia, que puede representar un reto diagnóstico, clínico e histológico, y un reto terapéutico local, adyuvante y de la enfermedad avanzada. La edad media de los pacientes es de alrededor de 67 años, y no se ha observado preferencia según el sexo. Se presenta con mayor frecuencia en las axilas y en el cuero cabelludo. Se caracteriza clínicamente por un lento crecimiento, aunque puede progresar agresivamente, con compromiso local, ganglionar y metastásico, principalmente, pulmonar, hepático y óseo. El tratamiento recomendado -una vez establecida la histología- consiste en una resección local amplia con un margen claro de 1 a 2 cm y linfadenectomía regional si se detectan ganglios clínicamente positivos. El tratamiento adyuvante (radioterapia o quimioterapia) y de la enfermedad avanzada no está claramente establecido. Se presentan dos pacientes de sexo femenino con sospecha inicial de cáncer de mama, en quienes se diagnosticó finalmente un carcinoma apocrino de glándula sudorípara.

¿Carcinoma de mama o carcinoma de glándula sudorípara? Presentación de dos casos y análisis de la literatura / Breast carcinoma or sweat gland carcinoma? A report of two cases and a comparison with the literature

Resumen El carcinoma apocrino primario de glándula sudorípara es una neoplasia con una muy baja incidencia, que puede representar un reto diagnóstico, clínico e histológico, y un reto terapéutico local, adyuvante y de la enfermedad avanzada. La edad media de los pacientes es de alrededor de 67 años, y no se ha observado preferencia según el sexo. Se presenta con mayor frecuencia en las axilas y en el cuero cabelludo. Se caracteriza clínicamente por un lento crecimiento, aunque puede progresar agresivamente, con compromiso local, ganglionar y metastásico, principalmente, pulmonar, hepático y óseo. El tratamiento recomendado -una vez establecida la histología- consiste en una resección local amplia con un margen claro de 1 a 2 cm y linfadenectomía regional si se detectan ganglios clínicamente positivos. El tratamiento adyuvante (radioterapia o quimioterapia) y de la enfermedad avanzada no está claramente establecido. Se presentan dos pacientes de sexo femenino con sospecha inicial de cáncer de mama, en quienes se diagnosticó finalmente un carcinoma apocrino de glándula sudorípara.

Abstract Primary apocrine carcinoma of the sweat gland is a neoplasm with a very low incidence that may represent a clinical and histological diagnostic challenge, as well as for adequate local, adjuvant, and advanced disease management. The average age of patients is around 67 years with no gender preference. This cancer develops primarily at the axillary and scalp levels and is clinically characterized by slow growth, but can progress aggressively with local, nodal, and metastatic involvement (primarily lung, liver, and bone). The recommended management, once the histology is established, consists of a wide local resection with a clear margin of 1 to 2 cm and regional lymphadenectomy if clinically positive nodes are detected. The adjuvant treatment (radiotherapy or chemotherapy) and for the advanced disease is not established. We report here the cases of two female patients initially diagnosed with breast cancer who were finally diagnosed with apocrine carcinoma of the sweat gland.

Cutaneous squamous cell carcinoma with mucinous metaplasia in dogs

Background: Squamous cell carcinoma (SCC) is one of the most common malignant skin tumors in domestic animals. Histologically, they are characterized by a proliferation of neoplastic keratinocytes with varied keratin production. Some SCCs have peculiar histological characteristics that permit them to be classified into uncommon to rare histological subtypes, reported in animals and humans. However, according to the authors' knowledge, the mucin-producing subtype described in humans has not yet been reported in animals. In this study, we report the occurrence of two mucin-producing SCCs in dogs, a histological presentation similar to that seen in cutaneous SCCs with mucinous metaplasia in humans. Cases: Two dogs, a 5-year-old Yorkshire female and a 17-year-old Dachshund male, had a skin nodule near the tail and on the right eyelid. The nodules varied from 1 to 5 cm in diameter, were firm and covered with skin and hair. The cut surface was firm and white. Histological findings were compatible with squamous cell carcinoma, characterized by a neoplastic proliferation of keratinocytes originating in the epidermis and infiltrating the dermis. The keratinocytes were arranged in islands and occasional anastomosed cords, supported by a fibrous stroma. The formation of pearls varied from moderate to sparse. The nuclear and cellular pleomorphism was accentuated in case two and moderate in case one. Mitosis figures ranged from two to five in a high magnification field. Within the neoplasm, there were large vacuolated neoplastic cells with slightly fibrillar intracytoplasmic basophilic content. This content has been rarely observed in an extracellular medium. The presence of mucin was confirmed by positive Alcian Blue (AB) staining. In immunohistochemistry (IHC), tumor cells showed strong immunostaining for pancitokeratin, and in areas with marked mucin deposition, immunostaining was predominantly moderate to weak. No tumor cells were immunostained for CD34 and Bcl-2 antibodies. Compared to AB and Harris' hematoxylin, it was possible to demonstrate the presence of mucin in the cytoplasm of neoplastic keratinocytes using IHC. No vascular or lymphatic invasion by neoplastic cells was observed. The average cell proliferation index assessed by counting the nucleolar argyrophilic organizing regions (AgNOR) was 3.4 in case 1 and 4.5 in case 2. Discussion: Although the SCC routinely does not present a diagnostic challenge in veterinary practice, the histological presentation of the reported cases does not fit the current classification available in veterinary medicine. The histological presentation observed in these two dogs is similar to that described for cutaneous SCCs with mucinous metaplasia in humans, and so far not described in animals. The observation of intracytoplasmic mucin in humans is an essential finding for the diagnosis of SCC with mucin metaplasia. In the present cases, we observed a slightly basophilic amorphous substance in the cytoplasm of proliferated neoplastic keratinocytes, which stained strongly in blue when applied the Alcian Blue (AB) histochemical technique. This observation became more evident when using IHC counterstained with AB and Harris hematoxylin. In the histological analysis, the absence of an adenoid growth pattern or glandular formation amid neoplastic proliferation ruled out the possibility of a mucinous adenocarcinoma or a mucoepidermoid carcinoma. In addition, we could rule out a follicular neoplasia, including keratinizing infundibular acanthoma due to the absence of a central pore and the absence of immunostaining for CD34 and Bcl-2. These immunohistochemical findings, together with histological findings, reinforce the diagnosis of SCC with mucinous metaplasia in our dogs.(AU)

Reflectance confocal microscopy in actinic keratosis-Comparison of efficacy between cryotherapy protocols.

BACKGROUND: Actinic keratosis (AK) incidence is increasing. Due to the risk of progression to squamous cell carcinoma, early detection and treatment are essential. The method stated in the European Consensus is cryotherapy, but there is no standard protocol defined for better results. OBJECTIVES: To compare two different cryotherapy protocols for AK using reflectance confocal microscopy (RCM) as a noninvasive imaging method for evaluation. METHODS: A self-controlled clinical trial was proposed to compare the efficacy of cryotherapy in two different application protocols. Grade II AKs in the forearms were submitted to freezing and thawing time of 10 seconds for 1 cycle (group A) or 2 cycles (group B). At baseline and 4 weeks after treatment, the same dermatologists assessed RCM evaluation (thickness of horny layer, parakeratosis, dyskeratosis, atypia in spinous layer, fibrosis, and presence of inflammatory cells in epidermis and dermis). RESULTS: We examined 24 AK lesions in each group. Statistical evaluation of the results evidenced superior response after 2 cycles of cryotherapy in parakeratosis and number of inflammatory cells in epidermis. CONCLUSION: Both protocols are effective in clearing clinical AK. Two cycles are not generating more side effects (fibrosis) and could reduce the risk of recurrence (better "clearance" of parakeratosis).

Evaluation of diagnostic criteria of actinic keratosis through reflectance confocal microscopy.

BACKGROUND: The diagnosis of actinic keratosis (AK) is based on clinical evaluation and confirmed by histopathological analysis (HA). The challenge is to establish the correct diagnosis with a minimally invasive assessment. The aim of this study is to validate the analysis of AK by reflectance confocal microscopy (RCM), a cellular resolution, noninvasive imaging method and to determine the relevant parameters for diagnosis, compared to HA, by calculating the sensitivity (S), specificity (E), positive predictive value (PPV), and negative predictive value (NPV) of each criterion. MATERIALS AND METHODS: Through clinical examination, 25 AKs were selected for dermoscopy and RCM evaluation followed by shaving excision for HA. Statistical analysis was done by hypothesis tests (McNemar for binary and Wilcoxon for continuous variables). RESULTS: There was no significant difference between RCM and HA for 5 of the 6 parameters analyzed. The criteria that were statistically relevant were as follows: parakeratosis (p-value 0.449690; S 90%; PPV 78.26%), hyperkeratosis (p-value 0.248213; S 87.5%; E 100%; PPV 100%; NPV 25%), dyskeratosis (p-value 0.617075; S 85.71%; E 75%; PPV 94.74%; NPV 50%), spinous layer keratinocyte atypia classified as mild, moderate or severe (P-value 0.145032) and inflammation in epidermis (P-value 1.000000; S 75%; E 20%; PPV 78.95%; NPV 16.67%). RCM could not adequately measure inflammation in dermis (P-value 0.013328), despite good sensitivity (68%) and PPV (100%). CONCLUSION: RCM proved to be an effective method for the diagnosis of AK, contributing to the selection of the most appropriate treatment option.

Dermatofibrosarcoma protuberans pigmentado: descripción de un caso pediátrico / Pigmented Dermatofibrosarcoma Protuberans: description of a pediatric case

Resumen: Introducción: El tumor de Bednar es un sarcoma de bajo grado, infrecuente, considerado como la variante pigmen tada del dermatofibrosarcoma protuberans (DFSP). Objetivo: describir las características clínicas, histopatológicas, el tratamiento y la evolución de un caso pediátrico de esta infrecuente neoplasia. Caso Clínico: escolar de 9 años que consultó por una pápula indurada asintomática, de dos años de evolución en el dorso del cuarto dedo del pie izquierdo. La biopsia incisional de la lesión fue com patibles con un DFSP pigmentado. El estudio inmunohistoquímico mostró positividad intensa para CD34 en toda la lesión, con factor XIIIa negativo. Se complementó el estudio de la pieza histológica con citogenética molecular FISH para el gen PDGFB (22q13.1) el cual reflejó un patrón anómalo en las células tumorales, no así en los melanocitos ni en la piel peritumoral. Se realizó cirugía micrográfica de Mohs diferida con cobertura mediante sustituto dérmico, sin recidiva ni recurrencia tumoral a los 5 años de seguimiento. Conclusiones: El DFSP pigmentado es un sarcoma de bajo grado, que muy infrecuentemente se presenta en pacientes pediátricos. Las variantes clásica y pigmentada deben ser sospechadas ante una lesión papulonodular única, de crecimiento lento y progresivo, con presencia de células fusiformes con patrón estoriforme en la biopsia y con estudio inmunohistoquímico positi vo para CD34. Es una entidad con buen pronóstico, con escaso riesgo de recurrencia y metástasis, si se logra la realización de una extirpación completa.

Abstract: Introduction: Bednar tumor is a rare low-grade sarcoma considered the pigmented variant of dermatofibrosarco ma protuberans (DFSP). Objective: To describe the clinical and histopathological characteristics, treatment and evolution of this rare neoplasm. Clinical Case: A 9-year old female presented with a 2-year history of an indurated, asymptomatic papule on the back of her fourth left toe. The incisio nal biopsy was compatible with pigmented DFSP. The immunohistochemical study showed intense positivity for CD34 throughout the lesion, with negative factor XIIIa. We complemented the study with molecular cytogenetics (FISH) for PDGFB gene (22q13.1) which showed an abnormal pattern in tumor cells, but not in the melanocytes or the peritumoral skin. Delayed Mohs surgery and skin substitute dressing were performed without neoplastic recurrence at 5 years of follow up. Conclu sion: Pigmented DFSP is a low-grade sarcoma that is very rare in pediatric patients. The classical and pigmented variants should be suspected in the presence of a single papulonodular lesion of slow and progressive growth, with presence of spindle cells with storiform pattern in the biopsy and positive immunohistochemical study for CD34. It is an entity with good prognosis, with little risk of recurren ce and metastasis, if complete excision is achieved.

Brain metastasis of Merkel cell carcinoma - A rare case report.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor. In our knowledge, only 30 cases of brain metastasis were reported in literature. The authors report a case of 57-year-old male with elevated intracranial pressure signs, which a frontal mass with pathological diagnosis of MCC. CASE DESCRIPTION: A 57-year-old male was admitted with a 3-month history of progressive headache, associated with nausea and dizziness. The magnetic resonance imaging showed a left frontal lobe, parasagittal, and nodular lesion with perilesional edema. The patient underwent complete surgical resection with success. The adjuvant treatment was radiotherapy and chemotherapy. CONCLUSION: In our knowledge, there is a little number of cases of MCC reported in literature. Surgical management is considered in cases with intracranial hypertension or focal signs. The adjuvant treatment options are immunotherapy and radiotherapy.

Metástasis cutáneas: como manifestación inicial y de recidiva de cáncer de mama: a propósito de un caso / Cutaneous metastasis as inicial and recurrence manifestation of breast cancer: a case report

INTRODUCCIÓN: Las metástasis cutáneas (MC) son un fenómeno poco frecuente en pacientes que padecen de cáncer de origen visceral, en mujeres se deben principalmente al cáncer de mama (CDM). Las MC se pueden presentar como manifestación de un cáncer avanzado o como signo de recidiva de un cáncer en remisión. La presentación clínica de un CDM en piel es muy variada, al estar presente es un indicador de enfermedad avanzada y , a su vez, de mal pronóstico, donde la variante clínica nodular es la más representativa. PRESENTACIÓN DEL CASO: Paciente femenina, 58 años. Con historia en 2005 de MC como primera manifestación de CDM. Presentó evolución satisfactoria y regresión de MC posterior a tratamiento con quimioterapia y radioterapia. Se resolvió quirúrgicamente, asociado a terapia hormonal, continuando en control ambulatorio. En 2018 consulta por lesión cutánea en pierna derecha, donde se constató además lesión cutánea mamaria izquierda. Se realizó biopsia de ambas lesiones que informó carcinoma epidermoide in situ en pierna derecha y metástasis dérmica de carcinoma ductal mamario con extensión intraepidérmica en zona mamaria izquierda y cervical ipsilateral. DISCUSIÓN: Las MC generalmente son precedidas por el diagnóstico de tumor mamario, rara vez son primera manifestación de él. De las MC cuya aparición es posterior al hallazgo de CDM, pueden observarse lesiones incluso al cabo de 10 años, lo que ha llevado a afirmar que el riesgo de enfermedad a distancia estará presente durante el resto de la vida. La presencia de MC por CDM implica generalmente amplia diseminación de la enfermedad, por lo tanto tener en cuenta este diagnóstico sería de gran ayuda en cuanto a oportunidad de tratamiento.

INTRODUCTION: Cutaneous metastases (MC) are a rare phenomenon in patients suffering from visceral cancer, in women they are mainly due to breast cancer (CDM). MC can occur as a manifestation of advanced cancer or as a sign of recurrence of a cancer in remission. The clinical presentation of a CDM in skin is very varied, being present is an indicator of advanced disease and, in turn, of poor prognosis, where the nodular clinical variant is the most representative. PRESENTATION OF THE CASE: Female patient, 58 years old. With history in 2005 of MC as the first manifestation of BC. After treatment with chemo and radiotherapy she presented satisfactory evolution and regression of CM. It was resolved later with surgery and hormonal therapy, continuing in ambulatory control. In 2018, the patient complained of a cutaneous lesion in the right leg. Physical exam also revealed a left mammary skin lesion. Biopsy was performed on both lesions. It reported carcinoma in situ in the right leg and dermal metastasis of mammary ductal carcinoma with intraepidermal extension in the left mammary and cervical area. DISCUSSION: CM are generally found after discovering the mammary tumor, they are rarely its first manifestation. As late manifestation of the disease, CM have been reported up to ten years later. The presence of MC by CDM generally implies a broad dissemination of the disease, taking into account this diagnosis could be of great help in terms of an opportunity for treatment.

Tricoepitelioma múltiple familiar: a propósito de un caso / Familial multiple trichoepithelioma: a case report

El Tricoepitelioma Múltiple Familiar (TMF) constituye una rara enfermedad autosómica dominante, se caracteriza por la aparición de múltiples pápulas color piel, monomorfas, simétricas, ubicadas en la región central de la cara. El diagnóstico es histopatológico, donde se encuentran tricoepiteliomas, los cuales son neoplasias anexiales benignas que se originan en los folículos pilosos. La condición es de comportamiento indolente, pero con una importante repercusión estética y de difícil manejo. Al ser esta una entidad poco frecuente, el objetivo de este artículo es actualizar los aspectos más relevantes de esta enfermedad. Se presenta el caso de una paciente de 23 años con lesiones faciales típicas en quien se confirmó el diagnostico de TMF

Familial Multiple Trichoepithelioma (FMT) is a rare autosomal dominant disease, characte-rized by the appearance of multiple papules of skin color, monomorphic, symmetrical and located in the central region of the face. The diagnosis is based on histopathological features of trichoepitheliomas, which are benign adnexal neoplasms that originate in the hair follicles. The condition has an indolent behavior but it has an important aesthetic repercussion and it's difficult to treat. As this is a rare entity, the objective of this article is to update the most relevant aspects of this disease. We present the case of a 23 year old patient with typical facial lesions in whom the diagnosis of FMT was confirmed.

Carcinoma basocelular en región plantar / Basal cell carcinoma of the plantar surface of the foot

RESUMEN: El carcinoma basocelular (CBC) es el tumor maligno de piel más frecuente (75% - 80%), localizado generalmente en zonas de exposición solar, aunque en algunos casos se presenta en áreas no fotoexpuestas (1%), lo que puede indicar la participación de otros factores etiológicos diferentes a la radiación ultravioleta. El CBC es decrecimiento lento, bajo potencial metastásico, pero localmente invasivo, por lo que es importante realizar un diagnóstico oportuno, conociendo las características clínicas e histológicas de esta entidad. Se presenta el caso de un paciente de 66 años, con una lesión en región plantar izquierda de dos años de evolución, evaluado por el Departamento de Dermatología, quienes confirman el diagnóstico de CBC nodular, mediante la realización de biopsia incisional y posterior resección con márgenes de seguridad de 4 mm. El CBC delocalizaciónplantar, a pesar de ser poco frecuente, debe sospecharse si se presenta una lesión tumoral, de evolución crónica.

SUMMARY Basal Cell Carcinoma (BCC) is the most frequent malignant tumor (75% - 80%), generally located in sun-exposed areas, although some can occur in areas that are not (1 %). The prior indicates that there are other factors involved in its etiology different from UV radiation. BCC is a slow growing tumor with poor metastatic potential but locally invasive, the reason why a prompt diagnosis is required, by knowing thoroughly its clinical and histopathological features. We present the case of a sixty-six-year-old male patient referred to the dermatology department, with a two-year evolution lesion in the plantar surface of his left foot. Diagnosis of nodular BCC is done through incisional biopsy and posterior resection is performed with a 4 mm safety margin. Although plantar BCC is infrequent, it should always be suspected when finding a chronic tumoral lesion in this area.