Computed tomography of traumatic serosanguineous cysts

Giant post-traumatic cyst after closed degloving injury

Post-traumatic cysts of soft tissue usually occur at the junction of the subcutaneous fat and deep fascia, most often filled with serosanguinous fluid and lined with fibrous tissue. It appears as complication after closed degloving injuries when crushing and shearing forces cause separation of the skin and subcutaneous fat from the deep fascia and muscle, creating a cavity filled with hematoma and liquefied fat. This rare condition calls Morel-Lavallee lesion, which was first described by this French physician in 1853. Unrecognized injuries will evolve in cystic formation filled with serous fluid. Predestined regions of body for this kind of trauma are trochanteric, proximal thigh and ischiolumbal, most often associated with a pelvic girdle fracture. Long-standing Morel-Lavallee lesion may either remain stable or occasionally expand and can induce chronic pain. Sometimes, it is hard clinically to distinguish chronic cyst from cystic-tumor formation. Magnetic resonance imaging is the modality of choice for detection and revealing the exact size and location of these lesions. The best method of treatment is surgical excision with complete resection.