Myolipoma

Myolipoma is a rare tumor that is typically benign. It is composed of mature adipose tissue and smooth muscle tissue. Myolipomas are most commonly found in the abdomen, but can also occur in the retroperitoneum, thigh, and uterus.

History

Myolipoma was first described in the medical literature by Meis and Enzinger in 1991. Since then, fewer than 50 cases have been reported worldwide. Despite its rarity, myolipoma is an important diagnosis to consider in the differential of soft tissue tumors.

Pathology

Myolipomas are composed of a mixture of mature adipose tissue and smooth muscle cells. The proportion of these two components can vary widely from case to case. The adipose tissue is typically well-differentiated, while the smooth muscle cells can range from well-differentiated to atypical. Despite the presence of atypical cells, myolipomas are generally considered benign and do not metastasize.

Diagnosis

The diagnosis of myolipoma is typically made through histopathology following surgical removal of the tumor. Imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) can be helpful in identifying the location and size of the tumor, but are not definitive for diagnosis.

Treatment

The primary treatment for myolipoma is surgical removal of the tumor. Because myolipomas are typically benign, complete removal of the tumor is usually curative. In cases where the tumor is large or located in a difficult-to-reach area, partial removal may be performed with close follow-up to monitor for recurrence.

Prognosis

The prognosis for individuals with myolipoma is generally good. Because these tumors are typically benign, complete surgical removal usually results in cure. However, recurrence can occur, particularly in cases where complete removal was not possible.