A case of acquired smooth muscle hamartoma of the scrotum

Abstract

We report a case of acquired smooth muscle hamartoma (ASMH) of tunica dartos, believed to be only the fifth so far reported. A 24-year-old man had a 6-month history of an asymptomatic tight and thickened scrotum. The skin was difficult to pinch. A biopsy specimen from the skin showed increased and proliferated smooth-muscle bundles composed of well-differentiated and uniform spindle cells that showed typical features of acquired smooth muscle hamartoma. Interestingly, dilatations of the lymph vessels were noted in the upper dermis above the proliferated smooth muscles. It has been reported recently that long-standing severe lymphoedema may cause histological features mimicking ASMH. As the present case was not preceded by oedema of the scrotum, we consider this case to be true ASMH.

Acquired hyperplasia of the tunica dartos mimicking smooth muscle hamartoma

“…Five similar cases have been reported recently, 1,4 , 5 two of them diagnosed as SMH of the tunica dartos 1,5 . However, histopathology showed hyperplasia of the tunica dartos in all cases, without proliferation of another cell type 1,4 , 5 .…”

“…Five similar cases have been reported recently, 1,4 , 5 two of them diagnosed as SMH of the tunica dartos 1,5 . However, histopathology showed hyperplasia of the tunica dartos in all cases, without proliferation of another cell type 1,4 , 5 . In three of these patients, surgery or radiotherapy of the groin or repeated erysipelas preceded the diagnosis, 4 whereas the medical history of the other two patients was unremarkable 1,5 .…”

“…However, histopathology showed hyperplasia of the tunica dartos in all cases, without proliferation of another cell type 1,4 , 5 . In three of these patients, surgery or radiotherapy of the groin or repeated erysipelas preceded the diagnosis, 4 whereas the medical history of the other two patients was unremarkable 1,5 . We speculate that in our patient, chronic intertrigo may have led to long‐standing oedema that finally triggered the proliferation of smooth muscle cells of the tunica dartos.…”

A Case of Acquired Smooth Muscle Hamartoma on the Sole

“…ASMH appears later in life as a slightly hyperpigmented or hypertrichotic patch or plaque with associated itching, pain or numbness. These lesions are usually negative for Pseudo-Darier's sign 7 . The histopathologic hallmark of SMH is a local increase of large, randomly oriented bundles of smooth muscle cells with central, cigar-shaped nuclei.…”

Embryonal Rhabdomyosarcoma of the Tunica Dartos in the Scrotum

“…Genitourinary rhabdomyosarcoma can occur in the bladder, testis, epididymis, spermatic cord, paratesticular region, prostate, ureter, and other sites, 7 but only a few tumors (leiomyoma, leiomyosarcoma, primary lipoma, and smooth muscle hamartoma) have been reported to arise from the dartos muscle of the scrotum. [8][9][10][11][12] In addition, rhabdomyosarcoma is exceedingly rare in adults. Soft tissue sarcomas account for less than 1% of all adult malignant tumors, and rhabdomyosarcoma accounts for only 3% of all soft tissue sarcomas.…”