Leiomyosarcoma of the penis: a clinicopathologic study of 14 cases with review of the literature and discussion of the differential diagnosis.

Primary leiomyosarcomas of the penis are very rare. To date, less than 30 have been documented in the English language literature. In this report, we describe the clinical, histopathologic, and immunohistochemical findings in 14 cases retrieved from our files. The patients ranged in age from 43 to 62 years (mean age, 51 years) at the time of initial surgical resection. The tumors involved the prepuce (n = 1), prepuce and distal shaft (n = 1), circumcision scar line (n = 2), circumcision scar line and distal shaft (n = 1), shaft (n = 5), base of the penis (n = 3), and penis, not otherwise specified (n = 1). The lesions ranged in size from 0.5 to 6.0 cm (median size, 1.5 cm) in greatest dimension. Nine tumors were superficially located, two were of indeterminate depth, and three were deep-seated. The superficial tumors were relatively asymptomatic, and seven were reportedly present for 1 year to more than 20 years (median duration, 5 years) before medical attention was sought. In contrast, one deep-seated lesion caused dysuria and difficulty voiding, prompting the patient to seek a clinical opinion within only a few months of the apparent onset. Histologically, all tumors contained smooth muscle cells with both cytologic atypia and mitotic activity. Immunohistochemical studies were available for nine tumors, and immunoreactivity for desmin was present in all instances. All patients were initially treated with a local procedure. Follow-up information is available for 9 of the 14 patients (64%), with a median follow-up interval of 12 years 11 months. Three patients had multiple (two to four) local recurrences. Two of these patients were ultimately treated with a wide local excision or partial penectomy, and both were alive and well at last follow-up. In contrast, one patient, who had four local recurrences and refused a penectomy, developed a distant metastasis 10 months after the fourth recurrence. The best predictors of outcome are tumor depth and tumor size. Superficial leiomyosarcomas of the penis are optimally managed by wide local excision whenever this is technically feasible. Tumors with a deep-seated component may require more aggressive intervention to ensure complete removal.