mart-1-antigen and Testicular-Neoplasms

A 19-year-old male Caucasian, without prior medical history, noticed a painless right testicular mass. Physical examination revealed neither gynecomastia nor abnormal skin pigmentation. Serum alpha-fetoprotein, β-HCG and testosterone levels were normal. Sonography depicted an intratesticular diffusely hyperechoic lesion with acoustic shadowing. The patient underwent right orchiectomy. Histology revealed a benign large cell calcifying Sertoli cell tumour. This tumour is rare and may be associated with genetic abnormalities.

Topics: Adenoma; Biomarkers, Tumor; Calbindin 2; Calcinosis; Diagnosis, Differential; Humans; Male; MART-1 Antigen; Orchiectomy; Sertoli Cell Tumor; Testicular Neoplasms; Ultrasonography; Vimentin; Young Adult

Melan-A/MART-1 is a recently identified new melanocytic differentiation marker, which is recognized as an antigen on melanoma cells by cytotoxic T-lymphocytes. It is of interest for clinicians as potential immunotherapeutic target and it is relevant for pathologists as a novel diagnostic marker, since two antibodies (A103 and M2-7C10) have become available to study Melan-A/MART-1 expression on archival material. Both antibodies are useful in the differential diagnosis of melanocytic tumors, especially metastatic tumors, since they are more sensitive than HMB-45. Both antibodies are also of diagnostic value in the recognition of perivascular epithelioid cell tumors (angiomyolipoma, lymphangioleiomyomatosis, and clear cell tumor). Since A103 has the unique property of staining many steroid hormone producing cells, this antibody is also of value for the recognition of tumors derived from these cells, such as adrenocortical carcinomas. Both antibodies are likely to be included in the routine diagnostic armamentarium of many immunohistochemical laboratories in the near future.

Topics: Adrenal Cortex Neoplasms; Angiomyolipoma; Antibodies, Monoclonal; Antigens, Differentiation; Antigens, Neoplasm; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Lymphangioleiomyomatosis; Lymphatic Metastasis; Male; MART-1 Antigen; Melanocytes; Melanoma; Neoplasm Proteins; Ovarian Neoplasms; Skin Neoplasms; Testicular Neoplasms

The article reports the clinical, histopathological, and immunohistochemical findings of a 1-year-old boy presenting with isosexual pseudoprecocity attributable to a functioning Leydig cell tumor of the testis. The case appears to represent the youngest patient ever recognized with this well-known syndrome. Malignancy features were also for the first time initially assessed using criteria, retrospectively developed from the literature, for metastasizing Leydig cell tumor. All the following were found: infiltrative borders, cellular pleomorphism, high mitotic index (12-14/high-power field), high MIB-1 index (40%), P53 positivity in 50% of the cells, and bcl-2 positivity in 15% of the cells. Immunohistochemistry proved the cells of the tumor to be positive for inhibin, Melan-A, synaptophysin, cytokeratin, and calretinin and negative for S-100 and chromogranin A. Notably, lipochrome and crystals of Reinke were not found in the tumor cells. Although the neoplasm fulfilled the criteria for a potentially metastasizing Leydig cell tumor, there was no evidence of that event having occurred, perhaps as a result of early treatment or as indication that criteria developed for Leydig cell tumor of adults may not apply to children.

Topics: Antigens, Neoplasm; Calbindin 2; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Infant; Inhibins; Keratins; Leydig Cell Tumor; Male; MART-1 Antigen; Neoplasm Proteins; Puberty, Precocious; S100 Calcium Binding Protein G; Synaptophysin; Testicular Neoplasms

Large cell calcifying Sertoli cell tumor is a rare type of testicular tumor. Reported herein is a Japanese patient with this tumor not associated with Carney's complex. An 11-year-old boy was admitted to hospital because of left testicular enlargement, and radical orchiectomy was performed. Macroscopically, the tumor was well circumscribed and had a maximum diameter of approximately 2 cm. The cut surface showed a yellow-white solid mass. Histologically, the tumor was composed of large neoplastic cells with abundant eosinophilic cytoplasm with a tubular, trabecular, and solid arrangement and loose myxoid stroma with irregularly shaped calcification. Immunohistochemically, the tumor cells were positive for vimentin, S-100 protein, calretinin, inhibin-alpha, melan-A, and CD10, and type IV collagen and laminin were observed in the extracellular matrix around the tumor cells. The distributions of melan-A, CD10, and mitochondria were characteristically patchy; in contrast, they were diffusely distributed in the cytoplasm in a control case of Leydig cell tumor. The differences in immunostaining patterns for melan-A, CD10, and mitochondria as well as positivity for S-100 protein-beta might be useful diagnostic hallmarks of large cell calcifying Sertoli cell tumor for discrimination from Leydig cell tumor.

Topics: Antigens, Neoplasm; Calbindin 2; Calcinosis; Child; Collagen Type V; Diagnosis, Differential; Humans; Immunohistochemistry; Inhibins; Male; MART-1 Antigen; Microscopy, Electron; Neoplasm Proteins; Neprilysin; S100 Calcium Binding Protein G; S100 Proteins; Sertoli Cell Tumor; Testicular Neoplasms; Testis; Vimentin

The monoclonal antibody A103 to the melanocytic differentiation antigen Melan A stains human steroid-producing cells and their tumors. A total of 200 formalin-fixed, paraffin-embedded canine normal tissues and hyperplastic and neoplastic lesions of the adrenal gland, testis, and ovary were immunohistochemically tested for Melan A with antibody A103. Leydig cell tumors (23/23, 100%), Sertoli cell tumors (14/15, 93%), and adrenocortical adenomas (12/13, 92%) were consistently positive. Adrenocortical carcinomas (23/35, 65%) and granulosa cell tumors (10/17, 59%) were less frequently positive. All pheochromocytomas, seminomas, and dysgerminomas were negative. The pattern of staining was cytoplasmic, but nuclear staining was also frequently seen in normal Leydig cells and their tumors. As in human tumors, immunohistochemistry for Melan A stains many canine steroid-producing tumors and can be used to distinguish these tumors from those of nonstereidogenic cells.

Topics: Adenoma; Adrenal Gland Neoplasms; Animals; Antibodies, Monoclonal; Antigens, Neoplasm; Diagnosis, Differential; Dog Diseases; Dogs; Dysgerminoma; Female; Humans; Immunohistochemistry; Male; MART-1 Antigen; Neoplasm Proteins; Ovarian Neoplasms; Seminoma; Testicular Neoplasms