title: Granular cell tumor of the breast preoperatively diagnosed by fine-needle aspiration cytology: report of a case.
abstract: Granular cell tumors (GCTs) have a characteristic cytological appearance, and fine-needle aspiration cytology (FNAC) has been suggested to be the diagnostic modality of choice. However, the differential diagnosis has not yet been well described. We herein describe a rare case of GCT of the breast and discuss the differential diagnosis. A 53-year-old woman presented to our hospital with a left breast mass. In clinical and radiological examinations, the mass was suspected to be malignant. Cytologically, the tumor was composed of cohesive groups of cells with a syncytial appearance, and the cells contained abundant, finely eosinophilic cytoplasmic granules and small round-to-slightly-oval nuclei, thus suggesting the presence of benign GCT. The results of immunohistochemical staining supported the proposed deviation from Schwann cells. This case emphasizes the fact that GCTs are a rare but important possibility in the differential diagnosis of breast tumors, and that FNAC may provide clinically useful information on the management of such lesions.
authors.affiliation: Department of Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Akatsu
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Shigeto
authors.initials: S
authors.lastname: Uematsu
authors.forename: Eiji
authors.initials: E
authors.lastname: Tamagawa
authors.forename: Hiroharu
authors.initials: H
authors.lastname: Shinozaki
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kase
authors.forename: Kenji
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Shujiro
authors.initials: S
authors.lastname: Otsuka
authors.forename: Makio
authors.initials: M
authors.lastname: Mukai
authors.forename: Masaki
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D016586:Granular Cell Tumor / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011300:Preoperative Care