Coexpression of cytokeratin and vimentin intermediate filaments in benign and malignant sweat gland tumors

Abstract

The coexpression of cytokeratin and vimentin intermediate filaments has been immunohistochemically evaluated in 124 benign and malignant sweat gland tumors of various types in comparison to normal sweat glands. In addition, all neoplasms have been stained by an antibody to alpha-smooth muscle actin. Epithelial cells reacted with the pan-cytokeratin antibody lu-5. In normal sweat glands, vimentin immunoreactivity was restricted to myoepithelial cells and to some cells of the coiled duct. In benign sweat gland tumors (n = 88), coexpression of vimentin and alpha-smooth muscle actin was frequently found in basal cells of neoplasms considered to differentiate towards the secretory coil of the eccrine or apocrine gland. These included eccrine spiradenoma, apocrine cystadenoma, hidradenoma papilliferum, syringocystadenoma papilliferum, and cylindroma. Thus, in these tumors, vimentin-reactive cells corresponded to myoepithelial cells. Vimentin-positive cells were also found in 14 of 36 sweat gland carcinomas, including 1 case of sclerosing sweat duct carcinoma, 1 case of porocarcinoma, 4 cases of eccrine adenocarcinoma, 1 case of mucinous eccrine carcinoma, and 5 cases of apocrine adenocarcinoma. Co-expression of vimentin and alpha-smooth muscle actin was observed in some cells of eccrine and apocrine adenocarcinomas. Therefore, in these neoplasms, some vimentin-positive cells appear to represent myoepithelial cells. In contrast, vimentin-positive cells in all other malignant tumors did not express alpha-smooth muscle actin. Our results indicate that coexpression of cytokeratin and vimentin may be frequently found in a variety of benign and malignant sweat gland tumors. In the majority of these neoplasms, vimentin-positive cells correspond to myoepithelial cells. Because vimentin is not specific for myoepithelial cells, additional stains for alpha-smooth muscle actin should be performed to prove the myoepithelial nature of vimentin-positive cells.

Plasmacytoid cells in salivary-gland pleomorphic adenomas: evidence of luminal cell differentiation

“…It has been often difficult to identify vimentin immunostaining in MECs [18,24,33,37], probably due to its restricted distribution in the cytoplasm [19,23]. Despite this difficulty, the present and the previous [6,24,25] studies observed distinct vimentin staining in MECs.…”

Adenoid Cystic Carcinoma-Like Pattern in Spiradenoma and Spiradenocylindroma: A Rare Feature in Sporadic Neoplasms and Those Associated With Brooke-Spiegler Syndrome

“…3,4 Myoepithelial cells, although commonly encountered in classical spiradenoma and spiradenocylindroma, are not evident at the light microscopic level, but they are convincingly demonstrated by electron microscopy and immunohistochemistry. [5][6][7][8][9] Further morphologic variations include squamous, mucinous, and clear cell differentiation. Malignant transformation results in distinctive appearances including patterns resembling basal cell adenocarcinoma of the salivary gland, either low grade or high grade, infiltrating adenocarcinoma, or sarcomatoid (metaplastic) carcinoma.…”

Spiradenoma and Spiradenocylindroma With an Adenomatous or Atypical Adenomatous Component: A Clinicopathological Study of 6 Cases

“…These have been convincingly demonstrated by electron microscopy and immunohistochemistry. [9][10][11][12][13] Immunohistochemically, these cells have an incomplete myoepithelial cell phenotype. They are often p63 positive but usually lack simultaneous expression of S-100 protein or alpha-smooth muscle actin.…”