Acquired smooth-muscle hamartoma of the scrotum: a histological simulator?

BACKGROUND

In three cases of chronic scrotal lymphedema, histological and immunohistochemical changes were observed that were strikingly similar to an exceedingly rare lesion reported previously under the name of acquired smooth-muscle hamartoma (ASMH) of the scrotum. The clinical context indicated that the cases were reactive rather than hamartomatous in nature.

MATERIALS AND

METHODS

The histological and immunohistochemical findings of the three cases were compared to macroscopically normal scrotal specimens obtained during sex reassignment surgery in seven male-to-female transsexuals.

RESULTS

Compared to the seven controls, the three cases of chronic scrotal edema revealed a marked increase of dartos smooth-muscle tissue and of connective tissue of the scrotal skin and underlying soft tissues. Still, even the normal amount of scrotal smooth-muscle tissue may easily be misinterpreted as smooth-muscle hyperplasia.

CONCLUSIONS

Chronic scrotal lymphedema may induce hyperplasia of the dartos muscle, resulting in a histological appearance previously described as ASMH. This indicates that ASMH may not always represent a later onset of abnormality similar to congenital smooth-muscle hamartoma but, rather, may constitute a histological simulator.