Penile metastasis from rectal adenocarcinoma: a case report

Despite its rich vasculature, the penis is rarely involved by metastasis. Since the first description of penile metastasis in 1870, fewer than 500 cases have been reported in the literature. The pelvic organs are the main source of primary tumors that metastasize to the penis.

We report a case of a 46-year-old Arabic man who presented with erectile dysfunction and painful induration of the penile root. Eight months ago, he had undergone abdomino-perineal resection for rectal adenocarcinoma after neo-adjuvant chemotherapy. The histological evaluation of the resected specimen disclosed a ypT3N0 tumor with a poor therapeutic response (around 5%). An adjuvant chemotherapy by XELOX (oxaliplatin plus capecitabine) regimen has been prescribed for the patient. The magnetic resonance imaging (MRI) showed tumoral infiltration of penile structures and a biopsy of the corpora cavernosa was performed. The histological examination disclosed a penile metastasis from the patient's previous rectal adenocarcinoma. The patient is still alive and continues his adjuvant therapy.

Penile secondary tumors are very rare and usually occur in patients with advanced tumor stages. A diagnosis of penile metastasis should be considered in patients with a history of malignancies who present with genitourinary symptoms. These patients have a dismal prognosis as they often die in the year after the diagnosis.