Fine-needle aspiration of secondary malignancies of the penis: a report of three cases.

Metastatic malignancy to the penis is an uncommon clinicopathologic entity, with only 300 cases reported since 1870. Of the reported cases, 75% were secondary to genitourinary primary tumors. Priapism is the most frequent symptom, although dysuria, ulceration, and node formation have also been described. We report three cases of penile metastatic involvement from primary tumors in the urinary bladder (two cases) and prostate (one case), respectively. Fine-needle aspiration (FNA) cytology from the penile nodules was performed in each case. The smears in all cases were highly cellular, and atypical neoplastic cells were observed singly, in clusters, or in papillary formations. The cells were pleomorphic with hyperchromatic nuclei and prominent nucleoli. Immunocytochemistry was performed for keratin 8 and 18 and prostatic-specific antigen (PSA). In conclusion, although it has rarely been used as a diagnostic tool, FNA of the penis can be proved effective and safe in diagnosing a suspected secondary malignancy.