Abstract
Cancer of the male breast is an uncommon event with metastases to the breast occurring even less frequently. Prostate carcinoma has been reported as the most frequent primary to metastasize to the breast; however, the reverse has not been previously reported. Herein, we present, for the first time, a case of breast carcinoma metastasizing to the prostate gland. Prostate needle core biopsy revealed infiltrative nests of neoplastic epithelioid cells, demonstrated by immunohistochemistry (IHC) to be positive for GATA3 and ER and negative for PSA and P501S. A prostate cocktail by IHC study demonstrated lack of basal cells (p63 and CK903) and no expression of P501S. The patient's previous breast needle core biopsy showed strong ER positivity and negative staining for PR and HER2. Similar to the prostate, the breast was negative for CK5/6, p63, and p40. This case demonstrates the importance of considering a broad differential diagnosis and comparing histology and IHC to prior known malignancies in the setting of atypical presentation or rare tumors.
Highlights
Cancer of the male breast represents less than 1% of all breast cancers in the United States and incidence is increasing with recent approximations of 1.3/100,000 [1, 2]
Following needle core biopsies of his prostate, and due to high tumor density reported within the prostate, the patient was scheduled for a transurethral resection of prostate (TURP). and started on tamoxifen hormone therapy
Up to 20% of patients with secondary tumors of the prostate have no evidence of metastatic disease in additional sites [11]
Summary
Cancer of the male breast represents less than 1% of all breast cancers in the United States and incidence is increasing with recent approximations of 1.3/100,000 [1, 2]. Stage at diagnosis is a strong prognostic factor and men with triplenegative breast cancer have a worse prognosis [5]. Men with ER-positive cancer are reported to have a 30% reduction in risk of death compared with ER-negative breast cancer; that benefit applies only to the first 5 years from diagnosis, at which time ER positive and negative have a similar prognosis [5]. While primary carcinoma of the male breast is infrequent, metastatic carcinoma to the breast from distant organs is very rare comprising approximately 1.2–2.7% of all malignant breast tumors [7] with the prostate being the most common primary site [8]. We present a case of metastatic breast carcinoma to the prostate of a 63-year-old male. To the best of our knowledge, this is the first-case report of breast carcinoma metastatic to the prostate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
