Case Number : Case 2558 - 27 April 2020 Posted By: Iskander H. Chaudhry

Atypical Intradermal Smouth Muscle Neoplasm.

Leiomyoma 

Atypical intradermal smouth muscle neoplasm.

Yes, atypical intradermal smooth muscle neoplasm

Agree. Atypical intradermal smooth muscle tumor

If the lesion is entirely confined to the dermis, then AISMT. But if it extends into the Dartos muscle layer, should we call this leiomyosarcoma? There is no subcutaneous fat in the scotum.

Agree. Atypical intradermal smooth muscle tumor

from Dr. Chaudhry - See below:

Dear All,

Thanks for some great comments and diagnoses. Below is my report:

Skin with fascicles of smooth muscle (Desmin+, SMA+) in the dermis with irregular borders. The lesional cells have fusiform cells with longitudinal striation, thin, cigar-shaped nuclei with blunt ends. There is a low mitotic index but moderate atypia. Coagulative tumor cell necrosis is not present. Proliferation index is 20 percent.

The features fall short of a diagnosis of leiomyosarcoma, however, the lesion is at least an atypical smooth muscle tumour.