Fine needle aspiration diagnosis of carcinoma arising in an ectopic breast. A case report.

BACKGROUND Ectopic breast tissue has been found at many anatomic locations. Neoplastic and hyperplastic lesions similar to those that develop in the normal breast can occur in supernumerary ones. CASE A 45-year-old female presented with a 30-cm, firm, subcutaneous mass in the left side of the chest wall that was clinically considered an ectopic breast. Fine needle aspiration biopsy showed irregular clusters and single epithelial cells with marked atypia, pleomorphism and occasional magenta bodies. CONCLUSION This case illustrates that fine needle aspiration biopsy is a rapid and highly specific technique that can be used as the first diagnostic step in cases of carcinoma arising in an ectopic breast.