involucrin and Adenoma--Sweat-Gland

Eccrine syringofibroadenoma is a rare benign skin tumor, which usually develops on the extremities of elderly persons. We performed immunohistochemical and ultrastructural studies of a typical case of eccrine syringofibroadenoma that developed on the left heel of a 58-year-old man. The tumor consisted of anastomosing thin epithelial strands connected to the epidermis. There were many ductal or cystic structures, and their luminal cells were strongly positive to antibodies against carcinoembryonic antigen and epithelial membrane antigen. Filagrin and involucrin immunoreactivities were also detected in some cells surrounding the ducts. Keratins K1 and K10, co-expressed in the peripheral cells of normal acrosyringia, were colocalized in small cell clusters. Ultrastructurally, intracellular duct formation characteristic of developing acrosyringia was observed. Tumor cells containing globular keratohyaline granules with various electron densities were seen around some ductal structures. In these areas, keratinization took place without lamellar granule formation or prominent cornified cell envelope assembly. These results suggest acrosyringial differentiation of this tumor.

Topics: Adenoma, Sweat Gland; Antigens, Neoplasm; Carcinoembryonic Antigen; Cytoplasmic Granules; Eccrine Glands; Epidermis; Epithelium; Filaggrin Proteins; Foot Diseases; Humans; Hyalin; Immunohistochemistry; Intermediate Filament Proteins; Keratins; Male; Middle Aged; Mucin-1; Protein Precursors; Sweat Gland Neoplasms

The duct-like structures present in 7 cases of benign and malignant eccrine poroma were examined by immunohistochemical staining for carcinoembryonic antigen (CEA), involucrin, and S-100 protein. The demonstration of CEA and involucrin was helpful in the recognition of these structures. The overt immunopositivity precedes morphological evidence for duct formation. On the basis of the CEA immunostaining, the duct-like structures were divided into 4 types: 1) mature acrosyringeal structure, 2) cystic luminal structure lined by elongated cells, 3) immature acrosyringeal structure, and 4) vacuole- or dot-like potential lumen in a single cell. Involucrine was observed in the lining cells of 1) and 2). None of the 4 types showed positive reactivity for S-100 protein, suggesting the irrelevance of these structures to the secretory element of sweat gland. The polymorphism of the ductal formation tended to be more remarkably observed in malignant eccrine poromas than in the cases of benign eccrine poroma and poroepithelioma tested.

Topics: Adenoma, Sweat Gland; Adult; Aged; Aged, 80 and over; Biomarkers; Carcinoembryonic Antigen; Female; Humans; Immunohistochemistry; Male; Protein Precursors; Sweat Gland Neoplasms