Exceedingly rare. Most cases are misdiagnoses & represent metastases from breast or less often large intestine

Clinical features

•Exceedingly rare

•Head & neck

•Occasionally trunk & extremities

•Middle aged-elderly

•A similar tumor may present on the vulva

•M=F

•Firm dermal nodule or plaque

•Recurrences- 70%, metastases- 57%, mortality- 70%

Histological features

•Most cases are misdiagnoses & represent metastases from breast or less often large intestine

•No evidence of an epidermal origin but Paget’s disease is possible in vulval tumors

Dermal tumor +/- subcutaneous fat

•Nests & cords of epithelial cells showing ductal differentiation/intracytoplasmic lumina embedded in a dense fibrous stroma

•Eosinophilic cytoplasm & irregular vesicular nuclei with small nucleoli

•Variable pleomorphism & mitoses

•Perineural infiltration & lymphovascular invasion commonly present

•CK7 & CEA +ve

•ER, PR, c-erbB-2, S100 & GCDFP-15 variable