Cytokeratin Expression of Apocrine and Eccrine Poromas with Special Reference to Its Expression in Cuticular Cells

The study investigated cytokeratin (CK) expression in apocrine and eccrine poromas using immunohistochemistry on 12 cases of apocrine and 21 cases of eccrine poromas. It found that poroid cells were positive for CK1/5/10/14, CK5/8, and CK14, similar to outer cells of normal dermal sweat ducts, and showed varied staining with other CK antibodies. Cuticular cells consistently expressed CK1/5/10/14 and CK10/11, with variable expression of other CKs. The findings suggested that neoplastic cells in these poromas are related to dermal sweat duct cells, and cuticular cells are intermediate between inner and outer duct cells. While CK patterns alone couldn't differentiate apocrine from eccrine poromas, the data could aid in distinguishing apocrine poromas from other hair follicle-related tumors.