Florid xanthomatous pelvic lymph node reaction to metastatic prostatic adenocarcinoma. A sequela of preoperative androgen deprivation therapy.

We describe a florid xanthomatous histiocytic reaction in the pelvic lymph nodes of a patient treated with androgen deprivation therapy prior to radical prostatectomy. The xanthomatous reaction was so marked that it nearly obscured the presence of metastatic carcinoma in the same lymph nodes. A similar histiocytic reaction was also present in association with carcinoma in the prostatectomy specimen, a finding that was not identified in pretreatment biopsy specimens. No other known cause of pronounced histiocytic lymph node proliferation was present in this patient. Only one brief description of a xanthomatous reaction in lymph nodes associated with this treatment has been previously recorded in the literature to our knowledge. Other patients from our institution who were treated similarly preoperatively all had lymph nodes negative for tumor, and none demonstrated a xanthomatous tissue reaction, suggesting that this reaction may be a marker for metastatic tumor in the same lymph node.