A CASE OF MOREL LAVALLEE LESION

Morel-Lavalle effusions are the result of the skin and subcutaneous fatty tissue abruptlyseparating from the underlying fascia, a traumatic lesion that has been termed closed deglovinginjury. These effusions are common in the trochanteric region and proximal thigh, where they havebeen referred to as Morel-Lavalle lesions . In this region, the dermis contains a rich vascular plexusthat pierces the fascia lata. The disrupted capillaries may continuously drain into the perifascial plane,filling up the virtual cavity with blood, lymph, and debris. An inflammatory reaction commonly createsa peripheral capsule, which may account for the self-perpetuation and occasional slow growth of theprocess .Morel-Lavalle lesions have been listed under different names, including posttraumatic softtissue cyst, pseudocyst, Morel-Lavalle extravasation, or Morel-Lavalle effusion. MRI protocol includedaxial and coronal spin-echo T1-weighted sequence, axial T2, coronal STIR sequences. gadoliniumdimeglumine is used as contrast agent. A thin hypointense ring, likely representing a hemosiderin-laden capsule, circumscribed all lesions. They show homogeneous hyperintensity on both T1- andT2-weighted sequences and surrounded by a hypointense peripheral ring. This T1 signal-intensity isprobably related to the existence of methemoglobin, characteristic of subacute hematomas.Methemoglobin is first observed on the periphery of subacute hematomas and produces a concentricring sign.Longstanding Morel-Lavalle lesions show a MRI pattern that includes variable signalintensity on T1 and hyperintensity on T2- weighted sequences, and a hypointense peripheral rim.peripheral enhancement also be present. The heterogeneous hyperintensity on T2-weightedsequences correlates with the existence of hemosiderin deposition, granulation tissue, necrotic debris, fibrin, and blood clots characteristic of chronic organizing hematoma. The hypointenseperipheral ring represent a hemosiderin-laden fibrous capsule with mild inflammatory infiltrate, which is said to be relevant for the self-perpetuation of An Initiative of The Tamil Nadu Dr. M.G.R. Medical University University Journal of Medicine and Medical Sciences the lesion. Finally, the internal enhancement is probably related to the capillary formation in the lesion The history of trauma, the characteristic location, and the MRI features may contribute to a correct diagnosis in such cases