RESUMO
Morel-Lavallée lesions are posttraumatic hemolymphatic collections related to shearing injury of variable mechanism (severe trauma or low-velocity crush injury), resulting in disruption of interfacial planes between subcutaneous soft tissue and muscle and perforating lymphatics and blood vessels. A 69-y-old woman, without medical history, was admitted to the emergency ward for important pain located from her behind to the anterior face of the thighs. Physical examination revealed large semirecent hematoma with a large soft fluctuant area with hypermobility of the skin and cutaneous hyperesthesia, spreading from her behind to the anterior face of her thigs. Her symptoms were typical of a Morel-Lavallée lesion. The ultrasound examination revealed hypoechoic heterogeneous compressible fluid containing fat debris with irregular margins and lobular shape, localized between subcutaneous fat and deep fascia, without flow on color Doppler, confirming the acute Morel-Lavallée lesion. After evacuation by needle puncture, the collection reappearance was probably due to hemolymphatic fluid corresponding to type 1 of the Mellado and Bencardino classification of Morel-Lavallée lesions. Patients and Physicians should be aware of the worsening effects of balneotherapy on skin hematoma to prevent dramatic extension of Morel-Lavallée lesions.