Oncocitoma em carúncula: relato de caso / Oncocytoma of the caruncle: a case report

RESUMO O oncocitoma é um tipo de neoplasia rara na prática clínica e descrito na literatura, principalmente quando localizado no olho. Quando localizado nos anexos oculares, é mais frequentemente na carúncula. Analisou-se o caso de uma paciente de 74 anos, caucasiana, que relatou desconforto visual no olho esquerdo, e cujo exame físico mostrou lesão tumoral na carúncula esquerda, com volume moderado, presença de neovascularização e secreção excessiva. A excisão cirúrgica da lesão foi realizada sob sedação, e a peça foi enviada para avaliação anatomopatológica. A lesão foi diagnosticada histologicamente como oncocitoma, sem malignidade, e a paciente não apresentou recidiva após o procedimento. Embora raro, esse tumor deve ser reconhecido pelos oftalmologistas, devido ao risco já relatado de desenvolvimento de adenocarcinoma.

ABSTRACT Oncocytoma is a neoplasm rarely observed in clinical practice and reported in the literature, especially when located in the eye. When described in the ocular adnexa, it is most often located in the caruncle. The case of a 74-year-old Caucasian female patient is reported. She complained of visual discomfort in the left eye, and physical examination showed a tumoral lesion in the left caruncle, of moderate volume, presence of neovascularization, and excessive secretion. Surgical excision of the lesion was performed under sedation, and the specimen was sent for pathological examination. The lesion was histologically diagnosed as oncocytoma with no malignancy, and the patient presented no recurrence after the procedure. Although rare, this tumor must be recognized by ophthalmologists due to the risk of developing adenocarcinoma, as already reported.

Is thyroid nodule volume predictive for malignancy?

ABSTRACT Objective: We aimed to determine the roles of preoperative thyroid nodule diameter and volume in the prediction of malignancy. Subjects and methods: The medical records of patients who underwent thyroidectomy between January 2007 and December 2014 were reviewed. The nodule diameters were grouped as < 1 cm, 1-1.9 cm, 2-3.9 cm and ≥ 4 cm, and volume was grouped as > 5 cm3, 5-9.9 cm3 and > 10 cm3. ROC (Receiver Operating Characteristic) curve analysis was performed to find the optimal cutoff value of diameter and volume that can predict malignancy. Results: There were 5561 thyroid nodules in 2463 patients. Five hundred and forty (9.7%) nodules were < 1 cm, 2,413 (43.4%) were 1-1.9 cm, 1,600 (28.8%) were 2-3.9 cm and 1,008 (18.1%) were ≥ 4 cm. Malignancy rates were 25.6%,10.6%, 9.7% and 8.5% in nodules < 1 cm, 1-1.9 cm, 2-3.9 cm and ≥ 4 cm, respectively. When classified according to volume, 3,664 (65.9%) nodules were < 5 cm3, 594 (10.7%) were 5-9.9 cm3 and 1,303 (23.4%) were ≥ 10 cm3. The malignancy rates were 12.7%, 11.4% and 7.8% for the nodules < 5 cm3, 5-9.9 cm3 and ≥ 10 cm3, respectively (p < 0.001). In ROC curve analysis, an optimal cutoff value for diameter or volume that can predict malignancy in all thyroid nodules or nodules ≥ 4 cm could not be determined. Conclusion: In this surgical series, malignancy risk did not increase with increasing nodule diameter or volume. Although the volume of malignant nodules ≥ 4 cm was higher than that of benign nodules ≥ 4 cm, there was no optimal cutoff value. The diameter or volume of the nodule cannot be used to predict malignancy or decide on surgical resection.

Proliferaciones Oncocíticas de Glándulas Salivales: Estudio Estructural e Inmunohistoquímico de 7 Casos / Oncocytic Proliferations of Salivary Glands: Structural and Immunohistochemical Study of 7 Cases

RESUMEN: Los oncocitos son células originadas probablemente por transformación metaplásica del epitelio ductal o acinar de parótida y submandibular. Su proliferación puede originar condiciones patológicas que incluyen hiperplasias oncocíticas adenomatosas multinodulares (HOAM), oncocitomas y carcinomas oncocíticos. Los tumores oncocíticos constituyen el 1 % de todos los tumores salivales y entre el 82 y 90 % se desarrollan en la parótida; el resto se divide entre la glándula submandibular y las glándulas salivales menores. Las hiperplasias oncocíticas multinodulares son extremadamente raras. En el presente trabajo se analizaron 5 casos de oncocitomas de parótida y dos casos de HOAM, uno de parótida y otro de submandibular y se describieron las características estructurales e inmunohistoquímicas de los oncocitos. Cortes seriados de las biopsias incluidas en parafina se colorearon con Hematoxilina - Eosina, Hematoxilina/ácido fosfotúngstico (PTA/H), PAS y se marcaron con AC antimitocondrial, CK 5/6, CK 20 y EMA. Los tumores mostraron un crecimiento nodular encapsulado por tejido conectivo denso. En los cortes histológicos se identificaron oncocitos eosinófilos (oscuros) y granulaciones violáceas con PTA/H. En dos casos de parótida y el caso de HOAM de submandibular presentaron además oncocitos claros PAS positivos. La inmunomarcación fue positiva en todas las células siendo la marcación para mitocondrias periférica en los oncocitos claros. Las células eosinofílicas PTA/H positivas y con fuerte marcación con AC antimitocondrial, CKs y EMA confirman el diagnóstico de patología oncocítica. En tres casos coexisten oncocitos claros y oscuros. Las células claras son oncocitos que acumulan glucógeno en su citoplasma desplazando a las mitocondrias hacia la periferia. En el diagnóstico diferencial de este tumor debemos considerar los tumores salivales con células claras, el carcinoma renal metastásico, el tumor de Whartin, la variante de células claras del carcinoma epitelial/mioepitelial y el carcinoma mucoepidermoide con metaplasia oncocítica.

ABSTRACT: Oncocytes are cells probably originated by metaplastic transformation of the ductal or acinar epithelium of parotid and submandibular. Its proliferation can cause pathological conditions that include multinodular adenomatous oncocytic hiperplasia (HOAM), oncocytomas and oncocytic carcinomas. Oncocytic tumors make up 1 % of all salivary tumors and between 82 and 90 % develop in the parotid; the rest of the tumors are divided between the submandibular gland and the minor salivary glands. Multinodular oncocytic hyperplasias are extremely rare. In the present work we analyzed five cases of parotid oncocytomas and two cases of HOAM, one of parotid and the other of submandibular; structural and immunohistochemical characteristics of the oncocytes were described. Biopsies were included in paraffin, serial cuts were stained with H&E, Hematoxylin / phosphotungstic acid (PTA / H), PAS and were marked with antimitochondrial AC, CK 5/6, CKs 20 and EMA. The tumors showed a nodular growth encapsulated by dense connective tissue. The histological cuts showed dark eosinophilic oncocytes and violaceous granulations with PTA / H. In two cases of parotid and the case of submandibular HOAM, PAS positive clear oncocytes were also present. The immunostaining was positive in all the cells, being the labeling for peripheral mitochondria in the clear oncocytes. Eosinophilic cells PTA / H positive with strongly marked with antimitochondrial AC, CKs and EMA confirm the diagnosis of oncocytic pathology. In three cases, light and dark oncocytes coexist. Clear cells are oncocytes that accumulate glycogen in their cytoplasm, displacing the mitochondria to the periphery. In the differential diagnosis we should consider salivary tumors with clear cells, metastatic renal carcinoma, Whartin's tumor, the clear cell variant of epithelial / myoepithelial carcinoma and mucoepidermoid carcinoma with oncocytic metaplasia.

Cistoadenoma papilar oncocítico de glándula parótida: caso clínico / Papillary oncocytic cystoadenoma of the parotid gland: case report

RESUMEN El cistoadenoma es un tumor epitelial benigno raro de glándulas salivales, de crecimiento lento y asintomático, que forma grandes masas uni o multiloculares con desarrollo papilar intraluminal. Si bien es más frecuente en glándulas salivales menores, se ha destacado lo inusual de la lesión en glándulas salivales mayores. Se presenta el caso de una mujer de 60 años, quien consultó por una masa indolora, blanda y de consistencia quistica en glándula parótida derecha, de crecimiento lento y progresivo. Su evolución fue de varios meses con piel de la zona intacta. Se realizó parotidectomia superficial. El examen histopatológico demostró cistoadenoma papilar oncocitico, tumor que ha sido destacado por su infrecuencia, y con una manifestación en parótida sumamente rara y de variados patrones histológicos. Su reconocimiento es trascendente para el profesional en casos como el que se presenta, pues su diagnóstico diferencial incluye lesiones con aspecto clínico similar y en algunos casos comportamiento agresivo.

ABSTRACT The cystadenoma is a rare benign epithelial tumor of salivary glands, characterized by slow growing and asymptomatic presentation, forming large uni or multilocular masses with intraluminal papillary development. Although it is more frequent in minor salivary glands, it has been emphasized the unusual of the major salivary glands affection. We present the case of a 60-year-old woman consulting for a painless, soft mass with cystic consistency in the right parotid gland, slow and progressive growing. The tumor evolved for several months keeping the skin of the area intact. A superficial parotidectomy was performed. Histopathological examination demonstrated a papillary oncocytic cystadenoma, a tumor that has been noted for its low frequency, and with extremely rare parotid manifestation and varied histological patterns. Its recognition is relevant for the professional in cases such as the one presented, since its differential diagnosis includes lesions with similar clinical appearance and in some cases aggressive behavior.

Oncocytoma of the lacrimal gland: a case report / Oncocitoma de glândula lacrimal: relato de caso

ABSTRACT Here we describe a rare case of a benign tumor in the lacrimal gland of a healthy 4-year-old girl. Mild proptosis was the only abnormality observed on clinical examination. Magnetic resonance imaging of the right orbit revealed an oval, solid, well-circumscribed, homogeneous mass extending from the lacrimal gland and measuring 2.5 × 2.3 × 1.7 cm without any evidence of invasion into adjacent bones. The lesion was surgically excised and histological analyses defined the diagnosis of oncocytoma of the lacrimal gland. Although rare, oncocytoma should be included in the differential diagnosis of lacrimal gland tumors.

Resumo Nós descrevemos um raro caso de tumor benigno na glândula lacrimal em uma criança sadia de 4 anos de idade. Clinicamente, a paciente apresentava apenas uma discreta proptose. A ressonância nuclear magnética (RNM) de órbita direita revelou a presença de uma massa oval, sólida, bem-circunscrita, homogênea, se extendendo a partir da glândula lacrimal, medindo 2,5 cm x 2,3 cm x 1,7 cm, sem nenhum sinal evidente de invasão a estrutura óssea adjacente. A lesão foi cirurgicamente removida e analizada histopatologicamente, sendo estabelecido o diagnóstico de oncocitoma de glândula lacrimal. Apesar de raro, o oncocitoma deve ser incluído no diagnóstico diferencial de qualquer tumor originado da glândula lacrimal.

Oncocitoma: caso clínico / Oncocytoma: a clinical case

El oncocitoma es un tumor benigno que afecta varios órganos como tiroides, paratiroides, riñón y glándulas salivales, que consiste en la proliferación de células oncocíticas producidas por una gran hiperplasia mitocondrial. El oncocitoma representa menos del 1 por ciento de todos lostumores de las gandulas salivales. Cuando en estudios por imágenes de glándula parótida se observen múltiples pequeños nódulos con unamasa sólida o quística, el diagnóstico de oncocitoma debe ser considerado, especialmente en pacientes de sesenta o más años. El objetivo de este artículo es la presentación de un caso de oncocitoma y analizar el estado de arte de los casos reportados en la temática.

The oncocytoma is a benign neoplastic tumor that occurs in several organs, including the thyroid gland, parathyroid gland, kidneys, and salivary glands consisting of a proliferation of oncocytic cells produced by a large mitochondrial hyperplasia. The oncocytoma accounts for less than 1% of the whole salivary gland tumors.When multiple small nodules are found in the parotid gland with a large solid or cystic mass that is evident on imaging, a diagnosis of oncocytoma should be considered, particularly in patients of sixty years of age or older. The objective of this article is the presentation of a case of oncocytoma and the state of art of reported cases in this field.

Comparison of computed tomography findings between renal oncocytomas and chromophobe renal cell carcinomas

PURPOSE: To investigate and distinguish the computed tomography (CT) characteristics of chromophobe renal cell carcinoma (chRCC) and renal oncocytoma. MATERIALS AND METHODS: Fifty-one patients with renal oncocytoma and 120 patients with chRCC, diagnosed by surgery between November 2005 and June 2015, were studied retrospectively. Two observers, who were urologists and unaware of the pathological results, reviewed the preoperative CT images. The tumors were evaluated for size, laterality, tumor type (ball or bean pattern), central stellate scar, segmental enhancement inversion, and angular interface pattern and tumor complexity. To accurately analyze the mass-enhancing pattern of renal mass, we measured Hounsfield units (HUs) in each phase and analyzed the mean, maximum, and minimum HU values and standard deviations. RESULTS: There were 51 renal oncocytomas and 120 chRCCs in the study cohort. No differences in clinical and demographic characteristics were observed between the two groups. A central stellate scar and segmental enhancement inversion were more likely in oncocytomas. However, there were no differences in ball-/bean-type categorization, enhancement pattern, and the shape of the interface between the groups. Higher HU values tended to be present in the corticomedullary and nephrogenic phases in oncocytomas than in chRCC. Receiver-operating characteristic curve analysis showed that the presence of a central stellate scar and higher mean HU values in the nephrogenic phase were highly predictive of renal oncocytoma (area under the curve=0.817, p<0.001). CONCLUSIONS: The appearance of a central stellate scar and higher mean HU values in the nephrogenic phase could be useful to distinguish renal oncocytomas from chRCCs.

Carcinoma renal con translocación XP11.2: informe de un caso con énfasis en los diagnósticos diferenciales / Renal carcinoma with translocation XP11.2: a case report with emphases in differential diagnostic

En adultos el carcinoma de células renales con translocación Xp11.2 es una neoplasia poco frecuente representando menos del 1% de todas las neoplasias renales. Analizar las características morfológicas de un carcinoma con translocación Xp11.2 y establecer los posibles diagnósticos diferenciales de este tumor renal. Paciente femenina de 45 años de edad, quien en mayo de 2008 acudió a emergencia por dolor en flanco izquierdo. Un ecosonograma abdominal evidenció litiasis renal izquierda y lesión sólida en polo inferior, la cual fue confirmada por tomografía abdominal. Se realizó nefrectomía laparoscópica izquierda, sin complicaciones. El espécimen quirúrgico fue enviado al departamento de patología fijado en formol tamponado al 10% y procesado para histología e inmunohistoquímica. Macroscópicamente, se evidenció en el polo inferior renal una lesión tumoral de 45 mm x 40 mm x 35 mm, amarillenta-anaranjada, con áreas de necrosis. Las secciones histopatológicas mostraron una lesión epitelial con patrón predominante papilar. Las células tumorales mostraban bordes citoplasmáticos discretos, con citoplasma eosinófilo granular y zonas vacuoladas. Se evidenció variabilidad de la forma y contorno nuclear. La inmunohistoquímica mostró reactividad nuclear para el TFE3. La correcta clasificación de estos carcinomas es importante por los factores pronósticos y predictivos, ya que estas neoplasias pueden ser sensibles a agentes quimioterapéuticos que afectan los micro túbulos.

In adult life, the kidney carcinomas associated with Xp11.2 translocations are an infrequent neoplasia representing less than the 1% of all kidneys neoplasias. To analyze the morphologic characteristics of a carcinoma with Xp11.2 translocation and to establish the probable differential diagnostics of this kidney tumour. A 45 years-old female patient, who at May 2008 was admitted to emergency by left flank pain. An abdominal ultrasound showed a left renal lithiasis and a solid lesion at the inferior pole, which was confirmed by the abdominal tomography. A left laparoscopic nephrectomy was performed without complications. The surgical specimen was send to the pathology department in 10% buffered formalin and processed to histology and immunohistochemestry. Macroscopically was observed at the inferior kidney pole a yellow orange tumor lesion with necrosis and 45 mm x 40 mm x 35 mm in size. The histopathologic sections showed an epithelial lesion with papillary pattern. The tumour cells showed discrete cytoplasmatic borders, with granular eosinophil to vacuolated appearance. Nuclei showed variability in form and size. The immunohistochemical study showed a nuclear positivity to TFE3. The correct classification of these carcinomas is important due to the prognostic and the predictive factors, since these neoplasias could be sensible to the chemotherapeutics agents that affect the micro tubules.

Functional adrenal oncocytoma: a rare neoplasm.

Adrenal oncocytoma is a rare adrenal neoplasm with only 21 cases reported in English literature. These adrenal tumors are usually nonfunctional and hence incidentally detected. Most of these adrenal neoplasms are benign. We report a rare case of adrenal oncocytoma that was functional and was successfully managed by laparoscopic adrenalectomy.

Adenoma oncocítico de tiroides (adenoma de células de Hürthle): revisión del espectro morfológico a propósito de cuatro casos / Thyroid oncocytic adenoma: a review of the morphological spectrum in four cases

El cambio oncocítico es un agrandamiento del citoplasma ocasionado por la acumulación de mitocondrias, que se presenta en una amplia variedad de condiciones reactivas y neoplásicas. En la glándula tiroides, dicho cambio es un fenómeno de metaplasia que ocurre en distintas situaciones que provocan estrés celular y en ocasiones da lugar a verdaderas neoplasias benignas y malignas, entre las que destaca el adenoma oncocítico. A propósito de cuatro casos estudiados en el Departamento de Patología del Hospital ABC con características citomorfológicas inusuales que representaron un reto diagnóstico, hacemos una revisión del espectro morfológico de estos tumores. Las características presentadas incluyeron necrosis isquémica masiva posterior a toma de biopsia por aspiración, tamaño mayor al esperado en un adenoma, coexistencia con una neoplasia maligna independiente y características histológicas similares a las observadas en carcinoma papilar. Es de gran importancia para el patólogo conocer estas características, para evitar errores diagnósticos que puedan implicar un inadecuado manejo terapéutico.

Oncocytic change involves a cytoplasmic enlargement due to mitochondrial accumulation observed in a wide variety of conditions and in multiple organs. It can be reactive or neoplastic. In the thyroid gland, this change is a metaplastic phenomenon that takes place under different circumstances that promote cellular stress, and could even produce a true neoplasm, both benign or malignant. The oncocytic adenoma, a malignant tumor will be described. We analyzed four cases studied at the surgical pathology department of the American British Cowdray Medical Center in Mexico City that displayed unusual cytomorphological features. They became a diagnostic challenge and in order to solve it we reviewed their morphological spectrum. Tumor characteristics in all cases included: massive ischemic necrosis short after a fine needle aspiration biopsy was performed, unexpected large size, coexistence with a malignant independent neoplasm and cytological features similar to those observed in papillary carcinomas. It is of utmost importance for the pathologist to acknowledge the existence of these features in order to avoid diagnostic mistakes that could lead to unsuccessful treatment.

20 years of RET/PTC in thyroid cancer: clinico-pathological correlations

The RET/PTC oncogene has been isolated almost twenty years ago. During these years, the research has given a final answer to several questions. In fact, it has been demonstrated that: a) RET/PTC is an early event in the process of thyroid carcinogenesis and has a critical role in the generation of the papillary carcinoma; b) RET/PTC activation is essentially restricted to the papillary histotype and to the Hürthle thyroid tumors; c) its incidence increases after exposure to radiations. However, some questions have not found a final answer yet: a) which is the real frequency of RET/PTC activation? Likely it is around 20 percent, but this point is still questionable; b) which other gene modifications are required to lead a thyroid cell carrying a RET/PTC oncogene to the malignant phenotype?, and c) is there any correlation between RET/PTC activation and clinical parameters? We hope that these questions will have a clear answer in the near future.

O oncogene RET/PTC foi isolado há quase 20 anos atrás. Durante esses anos de pesquisa várias questões foram solucionadas. Na verdade, já foi demonstrado que: a) o RET/PTC é um evento precoce no processo da carcinogênese da tiróide e tem um papel crítico na geração do carcinoma papilífero; b) a ativação do RET/PTC está restrita essencialmente ao histotipo papilar e aos tumores de Hürthle; c) sua incidência aumenta após a exposição à radiação. Entretanto, algumas questões permanecem ainda sem uma resposta final: a) qual é a real freqüência de ativação do RET/PTC? Provavelmente em torno de 20 por cento, mas este número ainda é questionável; b) quais outras modificações gênicas são necessárias para transformar uma célula tiroidiana que possui oncogene RET/PTC no fenotipo maligno?; e c) existe alguma correlação entre a ativação do RET/PTC e parametros clínicos? Esperamos que essas questões sejam solucionadas em futuro próximo.

Thyroid cancer in toxic and non-toxic multinodular goiter.

BACKGROUND: Many authors have claimed that hyperthyroidism protects against thyroid cancer and believed that the incidence of malignancy is lower in patients with toxic multinodular goiter (TMG) than in those with non-toxic multinodular goiter. But in recent studies, it was reported that the incidence of malignancy with TMG is not as low as previously thought. AIM: To compare the thyroid cancer incidence in patients with toxic and non-toxic multinodular goiter. SETTINGS AND DESIGN: Histology reports of patients treated surgically with a preoperative diagnosis of toxic and non-toxic multinodular goiter were reviewed to identify the thyroid cancer incidence. Patients having a history of neck irradiation or radioactive iodine therapy were excluded from the study. MATERIALS AND METHODS: We reviewed 294 patients operated between 2001-2005 from toxic and non-toxic multinodular goiter. One hundred and twenty-four of them were toxic and 170 were non-toxic. Hyperthyroidism was diagnosed by elevated tri-iodothyroinine / thyroxine ratios and low thyroid-stimulating hormone with clinical signs and symptoms. All patients were evaluated with ultrasonography and scintigraphy and fine needle aspiration biopsy. STATISTICAL ANALYSIS USED: Significance of the various parameters was calculated by using ANOVA test. RESULTS: The incidence of malignancy was 9% in the toxic and 10.58% in the non-toxic multinodular goiter group. Any significant difference in the incidence of cancer and tumor size between the two groups could not be detected. CONCLUSIONS: The incidence of malignancy in toxic multinodular goiter is not very low as thought earlier and is nearly the same in non-toxic multinodular goiter.

Oncocitoma renal: características clínicas y anatomopatológicas: reporte de 7 casos / Renal Oncocytome: Anatomopathological and clinical characteristics

El oncocitoma renal es una neoplasia benigna, constituyendo una lesión rara del riñón. Clínicamente es indistinguible del carcinoma de células renales en donde la radiología muestra un tumor sólido renal cuyo diagnóstico definitivo es sólo mediante el estudio histológico. Objetivo: Conocer las características clínicas y anatomopatológicas de los pacientes con diagnóstico de oncocitoma renal. Material y Método: Se registró el total de pacientes con diagnóstico de tumor renal en el Hospital Clínico de la Universidad de Chile (HCUCH) durante el período comprendido entre enero de 1991 y diciembre de 2005. Se incluyó en el estudio sólo aquellos pacientes que fueron sometidos cirugía. Posteriormente se revisaron los informes histológicos de las biopsias obtenidas seleccionándose sólo los pacientes con diagnóstico de oncocitoma renal. Resultados: El total de pacientes con diagnóstico de tumor renal corresponde a 303 casos, de los cuales 7 casos correspondieron a oncocitomas. La prevalencia del oncocitoma es de 2,3 por ciento. El 71 por ciento (n=5) corresponde a pacientes de sexo masculino y 29 por ciento (n=2) femenino. La edad promedio es de 59.4 años (rango 40-76). El diámetro máximo promedio fue de 4,5 cm (rango 1,8-9). La localización sigue a continuación: 5 casos riñón derecho y 2 casos riñón izquierdo. Ningún caso presentó necrosis ni mitosis. Dos (29 por ciento) y tres (43 por ciento) casos presentaron permeaciones vasculares y extensión extrarrenal, sin embargo todos los pacientes evolucionaron de forma satisfactoria, sin recurrencia ni presencia de metástasis. Conclusión: El oncocitoma renal presenta baja frecuencia, se presenta en el sexo masculino con mayor frecuencia, siendo su diagnóstico principalmente un hallazgo imagenológico, presentándose preferentemente en la edad adulta. El principal diagnóstico diferencial lo constituye el carcinoma de células renales cromófobo, variante eosinófilo.

Context: kidney oncytoma is thought to be a benign tumor and a rare lesion of the kidney. Its differentiation from renal cell carcinoma is difficult for both showing a solid mass in the x-rays, being this possible only through histopathology. Objetive: To know clinical and histological characteristics of patients with kidney oncocytoma. Methods: The total of patients with kidney tumor diagnosis at the HCUCH during December 1990 and December 2005 where registered. Only surgical patients were included in this study. Histological samples were analyzed and those with kidney oncocytoma diagnosis were selected. Results: The total number of patients with kidney tumor was 303, seven of which had diagnosis of oncocytoma. The prevalence of kidney oncocytoma is 2.3%, 71% of which were men (n=5) and 29% women (n=2). Mean age of presentation was 59.4 years (range 40-76). Maximal mean diameter was 4.5 cms. (range 1.8-9). In terms of localization 5 were in the right kidney and 3 were in the left one. Conclusion: kidney oncocytoma is a rare lesion, presented mostly in men and elderly, being its diagnosis mainly as a founding in images. Its main differential diagnosis is chromophobe variant of renal cell carcinoma.

Oncocytoma of maxillary sinus--a rare presentation.

A case of Oncocytoma of maxillary sinus in a 73 years old female is reported along with a brief review of literature. To the best of our knowledge this extremely rare tumor is the first of its kind reported in Nepal. Literature review has revealed only four such cases originating from maxillary sinus.

Collecting duct carcinoma associated with oncocytoma

Collecting duct carcinoma (CDC) is a rare, highly aggressive malignant neoplasm that arises from the collecting duct epithelium of the kidney. CDC was reported to coexist with renal cell and transitional cell carcinomas. We report a rare case of CDC associated with oncocytoma, confirmed by the characteristic histological appearance and immunohistochemistry. We also review the epidemiological, histological and immunohistochemical criteria for diagnosis, in addition to the genetic and cytogenetic aberrations reported in the literature. Identification and reporting CDC is important for the establishment of treatment strategies and monitoring prognosis.

Oncocytoma of an Intraoral Minor Salivary Gland: Case Report and Review of Literature

Oncocytoma is a rare benign tumor of the salivary glandrepresenting not more than 1% of salivary tumors. It iscomposed of large epithelial cells, the oncocytes, whichare predominantly found, in senior adults, being moreprevalent in the eighth decade of life. It is located mainlyin larger salivary glands especially in parotid glands.The tumor usually presents as a solid mass, painless, ofslow growth, and rarely it is larger than 4 cm ofdiameter. There are few reports in literature on minorsalivary glands neoplasias. This work aims to presentand discuss a clinical case of a 71-year-old male patientwith a 20 X 10 mm asymptomatic nodular lesion, ofapproximately 14 years duration, located in the oralmucosa on the left side of the mouth, with clinical andsurgical diagnosis of fibroma. An excisional biopsy ofthe lesion was made and the specimen was embedded in10% formaldehyde solution and delivered to the OralPathology Laboratory of the Federal University ofPernambuco for analysis. The histopathologicalexamination was carried out by hematoxylin/eosin andPAS staining with and without diastase. The specimenwas diagnosed as a minor salivary gland oncocytoma.

Diffuse hyperplastic oncocytosis of parotid gland: a case report.

Oncocytic tumors of salivary glands are rare. Diffuse oncocytosis is the rarest lesion among 3 principal groups of oncocytic lesions as classified by WHO. Only seven cases have been previously reported in the literature. We report a case of diffuse hyperplastic oncocytosis of the parotid gland in a 63-year-old male with a brief review of literature. To the best of our knowledge this is the first case from Indian subcontinent.

Adrenocortical oncocytoma--a case report.

Oncocytic tumours of adrenal gland are rare lesions with approximately twenty-five cases being documented in literature. A majority of them are nonfunctional and benign. We report a case of adrenal oncocytoma in a 44-year-old male, who underwent a laparotomy for a large mass in the abdomen, which was located above the left kidney. Routine histopathological examination was suggestive of a benign tumour with cells resembling oncocytes. However, immunohistochemistry and electron microscopy helped to confirm the diagnosis of an adrenocortical oncocytoma.