Related Experiment Video
Updated: Aug 25, 2026

Intravital Microscopy of the Microcirculation in the Mouse Cremaster Muscle for the Analysis of Peripheral Stem Cell Migration
Published on: November 5, 2013
Acquired smooth-muscle hamartoma of the scrotum: a histological simulator?
E O van Kooten1, J J Hage, W Meinhardt
1Department of Plastic and Reconstructive Surgery, Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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.
