Intra-articular leiomyoma of the knee mimicking a ganglion cyst in a child: A case report and review of literature

INTRODUCTION AND IMPORTANCE: Angioleiomyoma is a rare benign soft tissue tumor of smooth muscle getting its origin from the muscular layer of vessel walls. The localized type of leiomyoma occurs on the skin, deep soft tissues, in the genitourinary, gastrointestinal, and respiratory tracts. CASE PRESENTATION: We report a case of a 16-year-old patient who presented with an intra-articular leiomyoma developed in the anterior cruciate ligament and treated with arthroscopy. CLINICAL DISCUSSION: Angioleiomyoma can occur anywhere in the body and is most often seen in the extremities, particularly the lower limbs, but is very rare in the knee joint. Angioleiomyoma should be included in the differential diagnosis of nodular lesions mimicking loose body, such as lipomas, inclusion cysts, ganglion, pigmented villonodular synovitis (PVNS), fibroma, nodular synovitis, hemangioma, synovial sarcoma, myopericytoma, leiomyosarcomas, glomus tumor. CONCLUSION: Angioleiomyoma related to the cruciate ligaments of the knee should be considered in the differential diagnosis of a painful knee especially when associated with a decreased of range of motion of knee. The arthroscopic debridement should be considered the treatment of choice in order to reliably restore active ROM.