title: Clear cell sarcoma of the neck which metastasized to the mammary gland.
abstract: Malignant neoplasms very rarely metastasize to the mammary gland, the incidence of which is reported as 0.5-2%. Clear cell sarcoma is a rare neoplasm, accounting for approximately 1% of all soft tissue tumors, which commonly occurs in the distal extremities of young adults aged approximately 20 to 40 years. So it is also called malignant melanoma of soft parts because it frequently produces melanin. We report a case of a 26-year-old woman who presented with a neck mass. The mass was surgically removed, and pathological diagnosis was clear cell sarcoma of the neck, harboring the EWS-ATF1 chimeric gene. Computed tomography detected a right breast mass 11 months after operation. She was referred to our department, and the right breast tumor was resected. Histopathological examination revealed a 2.5-cm, well-defined mass composed of nests of small, spindle-shaped tumor cells with abundant, clear cytoplasm containing round nuclei and prominent nucleoli. The tumor cells were immunohistochemically positive for HMB45, S-100, and Melan-A. These findings led to a diagnosis of metastasis of clear cell sarcoma to the mammary gland. This is the first report of clear cell sarcoma of the neck which metastasized to the mammary gland.
authors: Department of Breast Medical Oncology, the Cancer Institute Hospital of the Japanese Foundation for Cancer Research, and the Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors: Ippei
authors: I
authors: Fukada
authors: Seiichiro
authors: S
authors: Nishimura
authors: Masahiko
authors: M
authors: Tanabe
authors: Hidetomo
authors: H
authors: Morizono
authors: Masujiro
authors: M
authors: Makita
authors: Naoya
authors: N
authors: Gomi
authors: Rie
authors: R
authors: Horii
authors: Futoshi
authors: F
authors: Akiyama
authors: Takuji
authors: T
authors: Iwase
keywords: Breast cancer; Clear cell sarcoma; Metastasis to the mammary gland