Sigmoid colon adenocarcinoma has a high incidence among gastrointestinal tumors, and it very rarely metastasizes to the penis. The literature reports that the prognosis after penile metastasis is generally poor, with a median survival of about 9 mo. Metachronous isolated metastasis to the penis originating from sigmoid colon adenocarcinoma has not been reported so far. Here, we report a case of sigmoid colon adenocarcinoma with isolated penile metastasis occurring 2 years after surgery. The mass was pathologically confirmed as metastatic adenocarcinoma, and oral chemotherapy with capecitabine was given after surgery. The tumor did not recur during the 2-year follow-up period.

A 79-year-old man presented to the urology department with "a mass located at the root of the penis since 1 mo". Enhanced computed tomography (CT) examination suggested a 12 mm × 10 mm × 9 mm nodule at the root of the right penile corpus cavernosum. Cranial, pulmonary, and abdominal CT; and bone scan did not show any tumorigenic lesions. The carcinoembryonic antigen (CEA) level was slightly elevated (6.01 ng/mL, reference value 0-5 ng/mL). The patient had undergone laparoscopic radical sigmoidectomy for sigmoid colon cancer 2 years ago. The postoperative pathology showed moderately differentiated adenocarcinoma of the sigmoid colon, and the stage was PT2N0M0. The penile mass was removed under general anesthesia. The postoperative pathology showed adenocarcinoma, and immunohistochemistry showed CDX2(+), CK20(+), and Villin(+). Based on the medical history, he was diagnosed with penile metastasis from sigmoid colon adenocarcinoma. The CEA level returned to normal (3.34 ng/mL) 4 d after surgery. Oral chemotherapy with capecitabine was given subsequently, and tumor recurrence was not found during the 2-year follow-up period.

To our knowledge, this is a rare case of metachronous isolated penile metastasis from sigmoid colon adenocarcinoma. The penis is a potential site of metastasis of colon adenocarcinoma, and the possibility of metastasis should be considered in patients with a history of colon cancer who present with a penile mass. Solitary penile metastasis can be removed surgically, in combination with chemotherapy, and it may have good long-term outcomes.

• Colon adenocarcinoma
• Penis
• Metastases
• Metachronous
• Adenocarcinoma
• Case report

Development of penile metastasis in patients with colorectal cancer is a rare condition and is associated with widespread metastasis and poor outcomes. We report a Case of metastasis to the penis with unique magnetic resonance imaging feature.

• Colorectal neoplasms
• Magnetic resonance imaging
• Neoplasm metastasis
• Penile induration
• Penis

• Adenocarcinoma/pathology
• Adenocarcinoma/therapy
• Antineoplastic Combined Chemotherapy Protocols/administration & dosage
• Camptothecin/administration & dosage
• Camptothecin/analogs & derivatives
• Colorectal Neoplasms/drug therapy
• Colorectal Neoplasms/pathology
• Colorectal Neoplasms/surgery
• Fatal Outcome
• Female
• Fluorouracil/administration & dosage
• Humans
• Leucovorin/administration & dosage
• Middle Aged
• Proto-Oncogene Proteins B-raf
• Skin Neoplasms/drug therapy
• Skin Neoplasms/pathology
• Skin Neoplasms/secondary

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.

• Adenocarcinoma
• Metastasis
• Pathology
• Penis