A clinicopathologic study of tumors and tumor-like lesions of the penis.

A total of 147 specimens from 93 patients with penile lesions were examined at Nagasaki University Hospital during a 27-year period from 1961 to 1987. The most frequent malignant tumor was squamous cell carcinoma (SCC, 33 cases, 35.5%), followed by extramammary Paget's disease, transitional cell carcinoma, and Bowen's disease. The benign tumors and tumor-like lesions included condyloma acuminatum, cyst of the genitoperineal raphe, and lymphangioma. SCC of the penis accounted for less than 0.1% of all specimens and less than 0.62% of malignant tumors in men filed at our hospital. True phimosis accompanied 81.5% of the SCC cases. The 5- and 10-year survival rates for SCC were 77.2% and 71.3%, respectively. Two patients died of penile SCC. It was considered that an absence of both keratohyaline granules in the granular layer and melanin pigment in the basal layer can serve as a useful histologic indicator for diagnosis of well differentiated SCCs that are otherwise difficult to identify.