PRIMARY MUCINOUS CARCINOMAS OF THE SKIN EXPRESS TFF1, TFF3, ESTROGEN-RECEPTOR, AND PROGESTERONE RECEPTORS

Mucinous carcinoma may present at various sites, including the breast and the gastrointestinal tract. Rarely, such tumors arise within the s kin. Comparatively, breast lesions are relatively common and usually a ssociated with a good prognosis. When pure, they are typically estroge n (ER) and progesterone receptor (PR) positive and responsive to tamox ifen. The authors studied 12 mucinous carcinomas of the skin and compa red the morphology with that of typical mammary lesions. The authors a lso evaluated for expression of estrogen receptor, progesterone recept or, and the mucus-associated peptides of the trefoil factor family (TF F), TFF1 (formerly pS2) and TFF2 (formerly SP), using immunohistochemi stry. The localization of mRNAs for TFF1, TFF2, and TFF3 (formally ITF ) was also studied in a subset of three tumors, using in-situ hybridiz ation with S35 labeled riboprobes. The Grimelius stain was used to loo k for evidence of neuroendocrine differentiation. Eight resembled type A mucinous carcinomas of the breast, two resembled type B, and one ha d composite features. The 12th was a papillary neoplasm. The two type B tumors exhibited argyrophilia. All showed strong nuclear staining wi th the estrogen receptor antibody but a more varied pattern with antib odies to progesterone receptor and TFF1. None labeled for TFF2. The de tection of TFF1 in mammalian skin is a novel finding. Cutaneous mucino us carcinoma shows strong similarities to its mammary counterpart, inc luding expression of estrogen receptor, TFF1, and TFF3 mRNA. These obs ervations suggest that some mucinous carcinomas of the skin might resp ond to antiestrogenic therapies.