This is a benign tumor of soft tissue.
Most leiomyomas occur in the uterus, so-called fibroids.
However, leiomyomas have occurred in nearly every organ and every location in the soft tissue. Under the microscope, they are nearly identical in every site. Clinically, it is one of the soft tissue tumors that present with pain. There is a prevailing view that leiomyomas of deep soft tissue are rare or nonexistent, but there are limited data on this subject in the form of large clinical studies with long follow-up information. Follow-up information was obtained to determine whether these stringent histologic criteria could identify a biologically benign group of smooth muscle tumors of deep soft tissue.