Vastus lateralis intramuscular lipoma incarcerating the lateral femoral cutaneous nerve (LFCN)

Abstract

Background: Intramuscular lipoma is an uncommon fatty tumor reported in up to 1.8% of all primary tumors of adipose tissue. It can occur at any age and is often found in the large muscles of the arms, legs and trunk. They have a slow growth and usually are asymptomatic. However, pain, paresthesia and decreased range of motion of the affected muscle have been reported.

Case Presentation: A 30-year-old male with a giant mass in the left thigh for 15 years, that grew rapidly for the past 5 years. He complained of pain and a burning sensation when pressure was applied on the mass. MRI revealed an intra-intermuscular lipoma measuring  31.6 x 10.3 x 11.6 cm.

Intervention: The patient underwent surgery. A giant mass attached to the vastus lateralis muscle and originating from the periosteal layer of the trochanter, was excised.

Outcome: The postoperative course was uneventful. Full range of motion in both the hip and knee joints was preserved. The patient remains under continuous follow-up.

Conclusion: Intramuscular lipomas are deep-seated lesions that may resemble well-differentiated liposarcomas. Surgical excision is the treatment of choice in symptomatic patients and is also indicated for cosmetic reasons, particularly for giant lipomas. When sensory peripheral nerves are incorporated within the mass, nerve coagulation with intramuscular rerouting can be performed.

Keywords: Giant intramuscular lipoma, liposarcoma, vastus lateralis, FCLN incarceration.