Clear cell eccrine carcinomas of the skin. A clinicopathologic study of nine patients.

BACKGROUND: Sweat gland carcinomas with clear cell features are extremely rare neoplasms, with few well documented cases reported in the literature. METHODS: Data on nine patients with malignant eccrine adnexal neoplasms characterized by a prominent clear cell neoplastic component were studied. Immunohistochemical stains with a panel of antibodies against epithelial, stromal, and neural antigens were performed on five tumors and electron microscopic examination of one. RESULTS: The tumors showed a spectrum of histologic features and growth patterns that ranged from well differentiated, low grade malignant neoplasms to poorly differentiated, highly aggressive, recurrent, and metastasizing tumors. All tumors contained a varied proportion of cells with abundant clear cytoplasm, similar to those seen in a group of benign eccrine adnexal neoplasms that have been variously designated as clear cell hidradenoma, nodular hidradenoma, clear cell myoepithelioma, and eccrine acrospiroma. Immunohistochemical stains on five tumors and ultrastructural examination in one were consistent with eccrine differentiation. Clinical follow-up of eight patients showed local recurrence in six, followed by metastases in three, despite local excision, radiation, and chemotherapy. Criteria for differentiating these tumors from their benign counterparts and from other types of malignant adnexal neoplasms and metastatic lesions are presented. CONCLUSIONS: The findings indicate that clear cell eccrine carcinomas comprise a heterogeneous group of lesions that may range from locally recurring, low grade well differentiated tumors to highly aggressive, high grade tumors with a definite potential for uncontrollable local recurrence and metastasis. Wide surgical excision is recommended as the primary treatment for such neoplasms.

Cytomegalovirus- and Cryptosporidium-associated acalculous gangrenous cholecystitis.

A well-documented case of cytomegalovirus- and Cryptosporidium-associated cholecystitis is described in a 19-year-old heterosexual Haitian man who had the acquired immune deficiency syndrome and acute acalculous gangrenous cholecystitis associated with these pathogens. This case adds to the spectrum of the manifestations of the profoundly immunocompromised state.

Mannosidosis. New clinical presentation, enzyme studied, and carbohydrate analysis.

Mannosidosis is a rare inborn error of metabolism characterized by deficiency of the lysosomal enzyme alpha-mannosidase and widespread storage of complex carbohydrate, which is enriched in mannose. Two affected unrelated males, aged 6 and 26 years, are reported. Both had a nonprogressive encephalopathy with moderately severe mental retardation. The older patient showed several unique features, including massive gingival hyperplasia associated with histiocytes containing large amounts of a material with the staining characteristics of glycoprotein. The best determinant of mannose storage proved to be the ratio of mannose to other carbohydrates in urinary polysaccharides. The enzyme deficiency in this disease is most convincingly demonstrated at pH values below 4.0. The ability of zinc to activate the mutant enzyme in vitro offers a possible mode of therapy for this disease. Retarded individuals with a Hurler-like appearance and gum hyperplasia of unknown cause should be screened for alpha-mannosidase deficiency.

Myxochondrosarcoma of the fourth ventricle. Case report.

The authors report a case of myxochondrosarcoma of the fourth ventricle. The tumor was heavily calcified and proved impossible to remove at surgery. Histological examination revealed areas of loose fibroblastic tissue, hyaline cartilage, osteoid, and bone. It is postulated that the tumor arose from the stroma of the choroid plexus.