Basal Cell Carcinoma of the Scrotum
Figure. Clinical photo on presentation, defect after Mohs micrographic surgery, and final linear closure.
A 72-year-old man presented to the clinic with a 1-year history of an asymptomatic growth on his right scrotum. He had been seen by dermatology a few months prior and was given the diagnosis of scrotal calcinosis. Past medical history included hypertension and high cholesterol. Surgical history included excision for squamous cell carcinoma (SCC) on his left upper back. On examination, there was a 1-cm pink pearly plaque on the right side of his scrotum without ulceration or drainage (Figure). Dermoscopic exam revealed arborizing vessels. Given these clinical findings, a shave biopsy was performed. Pathology results were consistent with a basal cell carcinoma (BCC), nodular type. The patient was scheduled for Mohs micrographic surgery. Negative margins were achieved after 1 stage of Mohs surgery and the surgical defect was closed with a linear closure (Figure).
Scrotal skin malignancies are very rare, with a reported incidence of only 1.5 per 100,000, and BCCs account for 17% of these.1,2 Additionally, while BCC is the most common type of skin cancer at all sites, accounting for 80% of all nonmelanoma skin cancers, fewer than 1% are located on the genitalia.1 BCCs on the scrotum have been reported to present as red papules or nodules, erythematous patches, and brownish plaques with or without ulceration.1 In general, BCCs have a reported metastatic risk of 0.0028% to 0.55%, most commonly to the lymph nodes, lungs, and bones.1 In review of 43 reported cases of scrotal BCCs, 5 (11.6%) had reported metastases while another study reported a 13% incidence of metastases.1,3 The most common reported locations were the lymph nodes and the lungs. This suggests that BCC of the scrotum may have a higher risk of metastasis than BCCs at all sites. However, both studies have a small sample size and there may be a reporting bias of cases that went on to develop metastases. Further studies are needed to elucidate how much more aggressive scrotal BCCs may be.
For BCCs at all sites, an increased risk for metastasis has been associated with older age, immunodeficiency, persistent neglected BCC, history of radiation, and large primary neoplasms.1 Pathologic findings associated with metastases are more aggressive subtypes such as morpheaform, infiltrative and basosquamous, increased depth of invasion, perineural or vascular invasion, and ulceration.1 Some of these clinical and pathological risk factors have been found in cases reporting metastases in scrotal BCCs as well.
The average age for scrotal BCCs has been reported as sixty-five.3 Rieder and colleagues reported that the genital region may often be unexamined by providers, which may allow lesions to be neglected and enlarge prior to diagnosis.4 Further, Dai and colleagues reported infiltrative and morpheaform subtypes in their 2 reported cases of scrotal BCCs, which went on to metastasize.1 Whether there are other tumor factors or regional characteristics that further increase this risk beyond that of other BCCs has not been discovered.
Article continues on page 2