title: Metastatic breast carcinoma mimicking primary thyroid neoplasm in young women.
abstract: OBJECTIVE
  To highlight awareness of the potential for breast carcinoma to manifest as a thyroid lesion.
  
  
  METHODS
  We present two case reports of young women with thyroid nodules and discuss diagnostic techniques and treatment strategies.
  
  
  RESULTS
  In two women, 32 and 38 years old, neither of whom had a history of carcinoma, thyroid nodules were suspected clinically of being primary thyroid neoplasms. In each case, histopathologic evaluation disclosed that the tumors appeared "foreign" to the thyroid and resembled infiltrating duct carcinomas of the breast. In some histologically confusing cases, immunostaining for thyroglobulin and calcitonin may prove diagnostically helpful. The usual treatment for lesions metastatic to the thyroid is surgical resection.
  
  
  CONCLUSIONS
  Metastatic breast carcinomas may manifest as primary thyroid lesions, especially in women younger than age 40 years.
authors.affiliation: University of Pennsylvania Medical Center, Department of Pathology and Laboratory Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Feldman
authors.forename: Z W
authors.initials: ZW
authors.lastname: Baloch
authors.forename: V A
authors.initials: VA
authors.lastname: LiVolsi