Isolated metastasis to the scalp in occult breast cancer: a clinical case

Abstract

Malignancies remain a serious socio-economic health problem worldwide. Among them, breast cancer (BC) in women ranks 1st in the structure and 4th in mortality. Occult breast cancer accounts for 0.1 to 1% of all BC. In this type, metastases to the scalp are extremely rare. This article presents a case of metastatic lesion of the scalp in occult breast cancer. Patient S., 82 years old, presented with a skin tumor in the parietal region, which she noticed about 2 years ago. It has grown recently, with local alopecia and hyperemia around the lesion. A comprehensive examination was performed. Cytology of the punctate showed malignant cells. Mammography and ultrasound showed no specific changes in the breast and lymph nodes. Spiral computed tomography of the chest and abdomen showed no signs of tumor. The lesion was surgically removed. Histological examination revealed adenocarcinoma metastasis. Immunohistochemical examination revealed tumor cells with diffuse and strong expression of estrogen receptors, diffuse and weak expression of progesterone receptors, strong and focal-diffuse expression of cancer embryonic antigen (CEA), and epithelial membrane antigen (EMA). The proliferative activity index of Ki-67 was less than 20%, Her2-neu 0. Considering the morphology and immunohistochemical data, the lesion was a metastasis of breast cancer with a luminal type A molecular biological variant. Skeletal bone scintigraphy revealed no metastatic lesions. The patient was diagnosed with an occult type of breast cancer, stage IV cTxN0M1, with metastasis to the scalp. Hormone therapy with aromatase inhibitors was administered. There were no signs of recurrence during the follow-up for 6 months. Isolated scalp metastasis in occult breast cancer is extremely rare. Practitioners should consider this type of distant metastasis of malignancies in differential diagnosis.