Kaposi Sarcoma Mimicking a Lingual Lesion in an HIV-Negative Patient: A Case Report.

Tonsillar Kaposi sarcoma is rare, reported in patients with human immunodeficiency virus (HIV) infection. This case report of a tonsillar Kaposi sarcoma (KS) in an HIV-negative male patient, initially misinterpreted as a lingual lesion diagnosed with KS following tonsillectomy, highlights the value of a differential diagnosis in atypical presentations. The case report discusses the etiologic agent of KS, its detection and treatment, and a few case reports about tonsillar KS with no association with AIDS. The case underscores the diagnostic challenge of oropharyngeal lesions, particularly in patients with risk factors but negative HIV status.

Detection of High-Grade Prostate Cancer With a Super High B-value (4000 s/mm2) in Diffusion-Weighted Imaging Sequences by Magnetic Resonance Imaging.

INTRODUCTION: High-grade adenocarcinoma of the prostate tends to have denser glandular structures and a prominent desmoplastic reaction, which could be detected by magnetic resonance imaging (MRI) with a super-high b-value in diffusion-weighted imaging (DWI) sequence, to differentiate it from low-grade carcinomas. OBJECTIVE: To evaluate the diagnostic validity of the diffusion sequence with values ​​of b4000 s/mm2 for the diagnosis of high-grade prostate cancer (Gleason score ≥ 7). MATERIALS AND METHODS: It is a retrospective analytical study of male patients who have undergone a prostate biopsy and count with a prostate MRI with a DWI sequence of a super-high b-value (4000 s/mm2). RESULTS: The sensitivity of the diffusion sequence with b4000 s/mm2 values ​​to classify as positive for prostate cancer was 57.14% as compared to biopsy. The specificity of the diffusion sequence with b4000 s/mm2 values ​​classifying patients with prostate carcinoma as negative was 84.62%. The probability that the diffusion sequence with b4000 s/mm2 values ​​classifies patients with prostate cancer was 80%. The probability that the diffusion sequence with b4000 s/mm2 values ​​does not classify patients with prostate cancer was 64.71%. The proportion of patients adequately classified with prostate cancer using the diffusion sequence with b4000 s/mm2 values ​​was 70.37%. CONCLUSIONS: The study shows that using the diffusion sequence with values of b4000 s/mm2 is an optimal value that serves as a tool to be able to decant those high-risk carcinomas with those of low risk; however, it is not a definitive method of diagnosis that could replace the performance of a biopsy. Since the study sample was limited, these results cannot be interpreted as reliable for diagnosing high-grade prostate cancer and should encourage future studies on a larger scale population to obtain significant evidence for a non-invasive diagnostic tool with a better cost-benefit for the patient.

Immunohistochemistry, Quality Control, and Principles of Validation in the Central Nervous System.

The conventional hematoxylin and eosin stain (H&E) is vital for the histological diagnosis but the role of immunohistochemistry (IHC) in the central nervous system is undeniable. Immunohistochemical techniques detect antigens in tissue sections by immunological and chemical reactions. This chapter reviews the preanalytic, analytic, and postanalytic phases of immunohistochemistry, as well as the principles of quality control and validation.

Sensitivity and Specificity of Ultrasonography Using Ovarian-Adnexal Reporting and Data System Classification Versus Pathology Findings for Ovarian Cancer.

Background One of the limiting factors for early diagnosis of ovarian neoplasms is the lack of standardized terminology for ultrasound. The Ovarian-Adnexal Reporting and Data System (O-RADS) classification aimed to reduce variability between observers and facilitate communication with attending physicians. Recent studies show that O-RADS has higher sensitivity (96.8%) and specificity (92.8%) compared to other classifications. However, to date, there are no reports on O-RADS correlation with pathology findings. Objectives To determine sensitivity and specificity of ultrasound, as a tool for detecting malignant ovarian neoplasms, using the O-RADS compared to pathology reports. Materials and methods We evaluated 73 transvaginal ultrasound records with adnexal masses and applied the O-RADS system. Then, we compared against definitive histopathology diagnosis. We calculated sensitivity and specificity using SPSS. Results O-RADS sensitivity for detection of ovarian cancer was 52%, with a specificity of 84%, negative predictive value of 79%, and positive predictive value of 60%, with an accuracy of 73%. Conclusions In our study, O-RADS classification yielded a higher specificity than sensitivity for malignant vs. benign findings. Hence, we propose that this classification could be useful for tailoring treatment appropriately. O-RADS 0 to 2 may benefit from conservative treatment while O-RADS 3 to 5 may require surgical treatment.

Paraganglioma maligno (múltiple, multicéntrico y metastásico) en una paciente con historia familiar de paraganglioma / Malignant paraganglioma (multiple, multicentric and metastatic) in a female patient with family history of paraganglioma

Los paragangliomas de comportamiento maligno son poco frecuentes, pero pueden ocurrir especialmente en pacientes con presentación familiar de la enfermedad. Presentamos el caso de una mujer de 23 años con diagnóstico de glomus carotídeo bilateral con metástasis ganglionares locales y a distancia, asociado a historia familiar de paraganglioma y presentamos una revisión de la literatura

Malignant paragangliomas are rare, but may occur especially in patients with familial forms of the disease. We present the case of a 23 year old woman diagnosed with bilateral carotid paraganglioma with distant and local metastases, associated to a family history of paraganglioma and we present a literature review

Malignant paraganglioma (multiple, multicentric and metastatic) in a female patient with family history of paraganglioma.

Malignant paragangliomas are rare, but may occur especially in patients with familial forms of the disease. We present the case of a 23 year old woman diagnosed with bilateral carotid paraganglioma with distant and local metastases, associated to a family history of paraganglioma and we present a literature review.

Primary pleural hybrid cellular schwannoma/perineurioma: a case report.

Hybrid schwannoma/perineurioma is a recently characterized benign nerve sheath tumor, most commonly affecting the lower limb and limb girdle. Hybrid tumors located in the subcutis of the trunk have not previously been reported to affect the pleura. We describe a 52-year-old man with dyspnea and thoracic pain due to a large mass in the right pleura, histologically composed of densely packed, S-100-positive spindle cells, intermixed with cells containing slender nuclei positive for epithelial membrane antigen, Glut-1, and claudin-1. To our knowledge, this is the first report of hybrid schwannoma/perineurioma in the pleura.

[Immunohistochemical Expression of CD117 (c-kit) in 75 Renal Cell Tumors]. / Expresión inmunohistoquímica de CD117 (c-kit) en 75 tumores de células renales.

OBJECTIVE: c-kit encodes the membrane-bound tyrosine kinase c-kit, whose expression has been identified in several human neoplasms. We analyzed the immunohistochemical expression of c-kit in renal cell tumors. METHODS: 75 cases of renal cell tumors were obtained from the surgical pathology archives at the ABC Medical Center in Mexico, for the period 2001 to 2011. We selected one representative paraffin block of the tumor and immunohistochemical staining for CD117 (c-kit) was performed. Immunopositivity was analyzed according cell location, intensity and percentage. RESULTS: c-kit was positive in 20 cases (26.66%), all the oncocytomas and chromophobe renal cell carcinoma were positive. A total of 8.27% of conventional clear cell renal cell carcinomas showed cytoplasmic positivity and one case of papillary renal cell carcinoma was positive. In chromophobe renal cell carcinoma c-kit was positive in the membrane and 44.44% showed combined staining. In oncocytoma four cases showed cytoplasmic positivity, with heterogeneous and less intense staining than chromophobe renal cell carcinoma. CONCLUSION: c-kit is a useful marker for the diagnosis of chromophobe renal cell carcinoma and oncocytoma vs. other renal cell tumors. Also it is important to define the cell location, intensity, and percentage of neoplastic cells for the differential between chromophobe renal cell carcinoma and oncocytoma.

[Metastatic oropharyngeal squamous cell carcinoma in cervical lymph nodes associated to HPV infection type 16 and 45; clinical, morphological and molecular study of two cases]. / Carcinoma epidermoide orofaríngeo metastásico en ganglios linfáticos cervicales asociado a los subtipos 16 y 45 del virus del papiloma humano (VPH). Estudio clínico, morfológico y molecular de dos casos.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma has been identified as a distinct entity within squamous cell carcinoma of the head and neck. In contrast to carcinomas associated with alcohol and/or tobacco, this subtype occurs at younger age, with frequent absence of classic risk factors, correlation with oral sexual habits, strong predilection for the palatial tonsils and the base of the tongue (lingual tonsils), basaloid or lymphoepithelial differentiation, higher degree of radiosensitivity, and overall better survival. We report two cases of lymph node, metastatic, poorly differentiated squamous cell carcinoma that were positive by immunohistochemistry for p16 with detection of HPV-16 and HPV-45 by PCR.

Primary monophasic synovial sarcoma of the tonsil: immunohistochemical and molecular study of a case and review of the literature.

Synovial sarcoma (SS) arises primarily in the lower extremities with a predilection for sites in proximity to large joints, such as the knee. It rarely occurs in the head and neck region, and the tonsil is an unusual site for the tumor, with only eight previously published cases in this anatomical site. We present a case of a primary monophasic SS arising in the right tonsil in a 63-year-old male. His medical history was noncontributory. Immunohistochemistry showed that cytokeratin OSCAR, EMA, Bcl-2, vimentin, PGP 9.5, and TLE1 were diffusely positive. A molecular analysis using RT-PCR indicated that the patient was positive for the SYT/SSX1 fusion transcript. A diagnosis of monophasic synovial sarcoma of the tonsil was made.

[Immunohistochemical comparison between GCDFP-15 and estrogen and progesterone receptors in the diagnosis of metastatic carcinoma of the breast]. / Comparación inmunohistoquímica entre la GCDFP-15 y los receptores para estrógenos y progesterona en el diagnóstico de carcinoma metastásico de la mama.

BACKGROUND: In the workup of tumors of unknown primary origin in women, a frequent consideration is breast carcinoma, because it is common and may initially present as metastasis. OBJECTIVE: Describe and compare the immunohistochemical profile of hormonal receptors (estrogen receptor and progesterone receptor) and GCDFP-15 in lymph node metastatic breast carcinoma according the histological grade. METHODS: Retrospective study analyzing 30 patients with identified primary breast cancer and lymph node metastasis. The cases were divided in three groups: grade I (well differentiated), grade II (moderately differentiated) and grade III (poorly differentiated). We used three antibodies (estrogen receptor, progesterone receptor and GCDFP-15) in the lymph node and compare the expression according the histological grade. RESULTS: In metastatic lymph node from grade I breast carcinomas the hormone receptors were 100% positive and GCDFP-15 was 80% positive. In grade II, estrogen receptor and progesterone receptor were positive in 90 and 40% respectively, and GCDFP-15 was positive in 80%. In grade III, estrogen receptor and progesterone receptor were positive in 30 and 50% respectively, and GCDFP-15 in 60%. CONCLUSIONS: The immunohistochemical expression of hormonal receptors and GCDFP-15 in metastatic breast carcinoma is related to histological grade in the breast.

Quiste de duplicación gástrica. Informe de un caso / Gastric duplication cyst. A case report

Los quistes de duplicación gástricos son hallazgos poco comunes en adultos porque habitualmente son detectados durante los primeros años de vida. Son el resultado de una alteración entre el ectodermo, la notocorda y el endodermo durante la embriogénesis temprana. Otra teoría está relacionada con el desarrollo del divertículo respiratorio, cuando la pared del quiste está revestida por epitelio de tipo respiratorio. Se informa el caso de una mujer de 52 años, previamente sana, asintomática, con una lesión quística abdominal de 4×2,7×2cm, localizada en la curvatura mayor del estómago y detectada por estudio de tomografía computarizada. Microscópicamente la pared del quiste estaba revestida por epitelio gástrico con túnica muscular completa y sin datos de malignidad. Se discute el origen embriológico de estas lesiones poco frecuentes(AU)

Gastric duplication cysts are usually discovered early in life and are therefore uncommon findings in adults. They are thought to result from a disturbance in the interrelations between the ectoderm, the notochord and the endoderm during early embryogenesis. Another hypothesis is related to the development of the respiratory diverticulum when the cyst wall is lined by pseudostratified respiratory epithelium with ciliated cells. We report a case of an asymptomatic 52-year-old woman with an 4×2.7×2cm abdominal cystic mass located in the greater curvature of the stomach and detected by CT scan. Microscopically, the cyst wall was lined by gastric mucosa with complete smooth muscle bundles. No sign of malignancy was found. The embryogenesis of this uncommon entity is discussed(AU)

Nontraumatic splenic pseudocyst. Case report.

BACKGROUND: Splenic cysts are uncommon and are classified as true cysts (with epithelial lining) and false cysts or pseudocysts. Splenic pseudocysts usually have a posttraumatic origin and are secondary to hematoma or to splenic infarction. At times there is no prior evidence of trauma, and the cyst may be secondary to a primary cyst with degeneration/atrophy of the epithelial lining. CLINICAL CASE: We present the case of a 50-year-old female with negative history of abdominal trauma. Clinically, the patient reported discomfort and pain in the left upper abdomen. Physical examination revealed a palpable and painful mass. reoperative ultrasonography and computerized tomography showed a large cyst in the spleen. Laparotomy and total splenectomy was performed. The cyst measured 9.5 × 9.0 cm. Histologically, the wall was composed of thick fibrous tissue, calcifications and no epithelial lining. CONCLUSIONS: "Nontraumatic" splenic pseudocyst is rare and may be secondary to a primary cyst with degenerative/atrophic changes in the epithelium. Clinically it is nonspecific, and symptoms are related to the mass effect of the cyst. Recommended treatment, according to the size of the cyst and its anatomic relation with the vasculature, is surgical with partial or complete splenectomy.

[Bilateral tonsillar hypertrophy as the first manifestation of B cell-small lymphocytic lymphoma with interfolicular pattern]. / Hipertrofia amigdalina bilateral como primera manifestación de linfoma de linfocitos pequeños B con patrón interfolicular.

B-cell small lymphocytic lymphoma typically involves nodal or extranodal tissues as a diffuse proliferation with proliferation centers (pseudofollicules) obliterating normal architecture. But there are unusual patterns of involvement including interfollicular pattern that can be difficult to recognize histologically and probably represent partial or early involvement by neoplasm. Tonsillar lymphoma usually presents either as a unilaterally enlarged palatine tonsil or as an ulcerative and fungating lesion over the tonsillar area. Most lymphomas that involve the tonsil are diffuse large B cell lymphomas and primary low-grade lymphomas are exceptional. We present a primary B-cell small lymphocytic lymphoma affecting palatine tonsils with interfollicular pattern in a 54 year-old man that clinically presented with symmetric / bilateral tonsillar enlargement and sleep apnea.

Meduloepitelioma pigmentado maligno intraocular. Presentación de dos casos / Intraocular malignant pigmented medulloepithelioma. A report of two cases

El meduloepitelioma intraocular es una neoplasiaembrionaria poco frecuente desarrollada en el cuerpo ciliar yque ocasionalmente afecta el iris, la retina o el nervio óptico.Presentamos dos casos de meduloepitelioma intraocularmaligno pigmentado, uno teratoide (con componente heterólogo:cartílago hialino) y otro no. Por histoquímica se reconocióla presencia de mucopolisacáridos ácidos y pigmentomelánico. Los estudios de inmunohistoquímica mostraronpositividad para marcadores de distintas líneas de diferenciacióncelular como neuroepitelial (proteína S100, sinaptofisina),glial (proteína ácida gliofibrilar), mesenquimatoso(vimentina, desmina), epitelial (citoqueratina AE1/3, EMA)y melanocítico (HMB-45, Melan-A). El meduloepiteliomaintraocular está compuesto por células multipotenciales conexpresión inmunofenotípica múltiple(AU)

Intraocular medulloepithelioma is a rare embryonaltumour that occurs most often in the ciliary body, but may alsoarise from the iris, retina or optic nerve. We present two casesof pigmented malignant intraocular medulloepithelioma; oneteratoid (with hyaline cartilage as a heterologous element),and one non-teratoid. Histochemistry showed the neoplasticcells synthesizing both an acidic substance that stained positivewith alcian blue and melanin pigment positive for Fontana-Masson stain. Immunohistochemistry showed positive stainingfor markers of several lines of differentiation includingneuroepithelial (S100 protein, synaptophysin), glial (GFAP),mesenchymal/muscle (vimentin, desmin), epithelial (cytokeratinAE1/3, EMA) and melanocytic (HMB-45, Melan-A).Intraocular medulloepithelioma is composed of multipotentialcells capable of polyimmunophenotypic expression(AU)