Abstract
A case of occult breast cancer, found after scalp metastasis is presented. An 84-year-old woman noticed a hard nodule (Φ4 cm) on her scalp. A skin biopsy was done, and histopathological findings showed suspected metastatic adeonocarcinoma. A whole body examination including PET revealed no evidence of malignant tumor in the mammary glands or other organs. Immunohistochemical findings showed that the tumor cells were positive for CK7, CK20, ER, PGR, while they were negative for CK5/6, p63. On the immunohistochemical features, metastasis of occult breast cancer was strongly suggested. It is very difficult to distinguish cutaneous metastasis of breast cancer from primary sweat gland carcinoma. But Marian Rollins et al. reported that the CK5/6 and p63 were weakly expressed in cutaneous metastasis of breast cancer, whereas they were strongly expressed in primary sweat gland carcinoma.[Skin Cancer (Japan) 2014 ; 29 : 195-200]
