title: Fine needle aspiration biopsy of neuroendocrine breast carcinoma metastatic to the thyroid. A case report.
abstract: BACKGROUND
  Tumors showing neuroendocrine differentiation arise in a wide range of organs, and metastatic neuroendocrine tumors may be difficult to differentiate from primary tumors. This report describes an unusual case of metastatic breast carcinoma with neuroendocrine differentiation that presented as a solitary thyroid nodule. The diagnosis was made by fine needle aspiration biopsy (FNAB).
  
  
  METHODS
  A 52-year-old woman presented with a thyroid nodule and bilateral enlarged supraclavicular fossa lymph nodes. FNAB revealed a neuroendocrine carcinoma. Further questioning revealed that the patient had had a breast carcinoma resected eight years previously. The diagnosis of metastatic neuroendocrine breast carcinoma was established by immunocytochemistry. The patient received antiestrogen therapy but subsequently developed skeletal metastases.
  
  
  CONCLUSIONS
  Neuroendocrine carcinomas from various sites show similar cytologic features. In this case, a diagnosis of breast carcinoma metastatic to the thyroid was suggested by the clinical history and confirmed by FNAB with immunocytochemistry.
authors.affiliation: Department of Anatomical Pathology, South Western Area Pathology Service, Douglass Hanly Moir Pathology, Sydney, New South Wales, Australia.
authors.forename: Christine K C
authors.initials: CK
authors.lastname: Loo
authors.forename: Ivan J
authors.initials: IJ
authors.lastname: Burchett
mesh_terms: D001707:Biopsy, Needle; D001859:Bone Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation; D002864:Chromogranins / Q000378:metabolism; D003581:Cytodiagnosis; D005260:Female; D006801:Humans; D008875:Middle Aged; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology / Q000556:secondary*; D016606:Thyroid Nodule / Q000473:pathology
chemical_list: D002864:Chromogranins; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D010751:Phosphopyruvate Hydratase