Metastasis to the penis in a patient with squamous cell carcinoma of the lung with a review of reported cases

Metastasis to the penis is very rare in lung cancer. We describe a patient with squamous cell carcinoma of the lung who developed a metastatic lesion in the penis. A 75-year-old Japanese male visited a local hospital complaining cough and bloody sputum. A chest plain radiograph and computed tomographic (CT) scans of the chest demonstrated a right hilar mass. He was diagnosed with squamous cell carcinoma of the lung at stage IIIB (T4N2M0). Then he was treated with concurrent chemoradiotherapy consisting of cisplatin, docetaxel, and thoracic irradiation, and after the chemoradiotherapy, he achieved a partial response. However, 6 months later, he visited an urologist complaining of firm mass in the penis with slight pain. A biopsy of the corpus cavernosum penis was performed, which provided a histological diagnosis of squamous cell carcinoma. The histology of the specimen was consistent with that of previous lung cancer, so he was considered to have penile metastasis from squamous cell carcinoma of the lung. Radiotherapy was given to the metastatic tumor in the penis. The penile tumor was diminished and the pain was completely relieved. In addition, we review reported cases to investigate the clinical characteristics and appropriate management of this rare involvement.