title: Unusual cases of metastases to the breast. A report of 17 cases diagnosed by fine needle aspiration.
abstract: BACKGROUND
  Although nonmammary tumors metastatic to the breast are relatively uncommon, a correct diagnosis is essential to appropriate management. Radiologically these lesions are single, round, discrete lesions without the spiculations of primary malignancies. Fine needle aspiration biopsy (FNAB) may provide a definitive diagnosis, thereby sparing patients unnecessary surgery.
  
  
  METHODS
  Seventeen cases of nonmammary malignancies diagnosed by fine needle aspiration of the breast were identified in the cytopathology files at three different institutions from 1989 to 1999. Three of the cases are of particular interest, including a mucoepidermoid carcinoma of salivary gland origin and a small cell undifferentiated carcinoma of rectal origin, neither of which has been reported in the literature previously. The third case was a male with a breast mass that was originally thought to be primary based on clinical, cytologic and immunocytochemical features but subsequently was determined to be a metastasis from the lung.
  
  
  CONCLUSIONS
  Virtually any malignancy may metastasize to the breast. FNAB is the best approach to the diagnosis of tumors that either clinically or radiographically are not typical of primary breast tumors. Extramammary neoplasms metastatic to the breast may be definitively diagnosed by FNAB, resulting in the most appropriate as well as cost-effective patient management.
authors.affiliation: Department of Pathology, Tulane University Medical School, SL79, 1430 Tulane Avenue, New Orleans, Louisiana 70112, USA.
authors.forename: Odile
authors.initials: O
authors.lastname: David
authors.forename: Paolo
authors.initials: P
authors.lastname: Gattuso
authors.forename: Wafai
authors.initials: W
authors.lastname: Razan
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Moroz
authors.forename: Nina
authors.initials: N
authors.lastname: Dhurandhar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000556:secondary*; D018567:Breast Neoplasms, Male / Q000175:diagnosis / Q000473:pathology* / Q000556:secondary*; D018277:Carcinoma, Mucoepidermoid / Q000175:diagnosis / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000473:pathology; D012468:Salivary Gland Neoplasms / Q000175:diagnosis / Q000473:pathology