The patient underwent right gluteal hematoma evacuation and debridement. 

Gross description: The specimen is received in formalin in one container, labeled with the patient's name, medical record number and "right gluteal sac". It consists of a previously opened cystic lesion measuring 15 x 10 x 9 cm and weighing 311 grams. The cystic wall thickness is 0.3 cm. One surface is smooth and glistening and the other surface shows focal hemorrhagic areas with fatty tissue. 

Microscopic description: Pseudocyst showing zones of fibrin, dense fibrosis, granulation tissue, foci of lymphohistiocytic inflammation & hemorrhage consistent with Morel-Lavallée lesion.

Case courtesy of Dr Ahmed Eid