Epidermotropic Metastasis from Lung Adenocarcinoma / 대한피부과학회지

ABSTRACT

Cancer metastasis to the skin, especially epidermotropic metastasis, is uncommon. Sometimes it is difficult to find the primary lesion; immunohistochemical (IHC) staining of cutaneous metastasis is used to determine the origin, but diagnosis may occasionally prove difficult. A 77-year-old man visited our hospital with a 1-month diagnostic history of multiple nodules in the right axilla. The patient had undergone surgery for gastric adenocarcinoma (T3N3M0) 21 years ago, and was diagnosed with lung adenocarcinoma 1 year previously; however, no treatment was ongoing. Biopsy of the lesions revealed atypical cells surrounding the papillary projections of the epidermis and tumor nests of the upper dermis. IHC staining was positive for CK7 and CEA and negative for CK5/6, CK20, napsin A, TTF-1, GCDFP 15, and p63. The tissues revealed glandular structures and tested negative for p63 and CK5/6 on IHC staining. The patient was diagnosed with epidermotropic metastasis of lung adenocarcinoma.