title: Primitive neuroectodermal tumor of the breast: immunohistochemistry and fluorescence in situ hybridization.
abstract: A case of primitive neuroectodermal tumor (PNET) that developed as a breast lump in a 47-year-old Japanese woman is reported. After fine-needle aspiration (FNA) cytology, a mastectomy was performed. The surgical specimen was a well-circumscribed tumor, 21 x 18 x 18 mm, localized in the breast. The tumor cells were small and round with scant cytoplasm, and proliferated in sheets or solid nests. No intraductal carcinoma component was present. The tumor cells were immunohistochemically positive for neural cell adhesion molecule (CD56), neuron-specific enolase and synaptophysin, and they showed membranous immunoreactivity for the MIC2 protein (CD99). Fluorescence in situ hybridization (FISH) indicated a rearrangement of the EWS region on chromosome 22, which is highly specific for Ewing's sarcoma and PNET, which are referred to as the Ewing's sarcoma family of tumors (EFT). No other lesions suggestive of the primary site of this tumor, such as bone, soft tissue, or other organs were detected. The patient has been disease free for 6 months after surgery followed by chemoradiation therapy. FISH is extremely useful for accurate diagnosis of EFT, especially in cases of unusual locations.
authors.affiliation: Department of Pathology and Laboratory Medicine, Yamagata Prefectural Central Hospital, Yamagata, Japan. gtamura@ypch.gr.jp
authors.forename: Gen
authors.initials: G
authors.lastname: Tamura
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Sasou
authors.forename: Shun
authors.initials: S
authors.lastname: Kudoh
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
authors.forename: Akira
authors.initials: A
authors.lastname: Ishikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D044963:Biopsy, Fine-Needle; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D002892:Chromosomes, Human, Pair 22; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D015413:Mastectomy, Simple; D008875:Middle Aged; D018242:Neuroectodermal Tumors, Primitive / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor