Morel-Lavallée Lesion with Intramuscular Extension: A Case Report

Abstract

Morel-Lavallée lesions (MLLs) are closed degloving injuries that occur between subcutaneous tissue and underlying fascia, creating a potential space that fills with hemolymphatic fluid. By definition, MLLs are located in the pre-fascial space and generally do not extend into muscle. An 83-year-old male presented with two mass lesions, sized 14 and 8 cm respectively in diameter, on the right lateral thigh. The lesions had been asymptomatically present for over 10 years but presented with recent inflammatory symptoms. Magnetic resonance imaging revealed two interconnected cystic masses under the subcutaneous fat layer, with an extension from the superior lesion into the tensor fasciae latae (TFL). Surgical exploration revealed a thick pseudocapsule filled with brown paste-like old hematoma and serosanguinous fluid. The interconnected upper lesion also had a pseudocapsule with sinus tract formation into an elongated fibrous cavity in the TFL. Serial debridement with removal of both capsules and most of the TFL supplemented by negative pressure wound therapy with continuous betadine instillation allowed delayed repair. This case demonstrates that intramuscular extension can occur in chronic MLL.