Bowen's disease with invasive carcinoma showing sweat gland differentiation

A 75-year-old Japanese woman presented an erythematous macular lesion on the flexor aspect of her left wrist. A reddish nodule, 4 mm in diameter, was observed at the medial portion of the macule. The macular lesion was histologically confirmed to be a typical Bowen's disease. The nodular lesion was composed of intradermal solid nests of bowenoid neoplastic cells, and in some areas of the dermal component, prominent gland-like structures were observed. Immunohistochemically, most neoplastic cells of the intradermal solid nests were positive with S-100 protein, and the cells lining the gland-like structures along with amorphous material within the lumens were positive with carcinoembryonic antigen. Judging from these findings, this case was diagnosed as Bowen's disease with invasive carcinoma, whose dermal component showed sweat gland differentiation not only morphologically but also immunohistochemically.