A 32 year old man came with abdominal distension since three months. He is known to have hemophilia.
Contrast enhanced CT scan of the abdomen shows a large, well-defined,hypodense, peripherally enhancing retroperitoneal 10 x 26 x 39 cm (vol.5500cc) collection within the right psoas muscle with presence of multiple air foci and hyperdense content. The collection extends caudally along the planes of right iliopsoas muscle into the proximal right thigh for distance of 10cm from right inguinal ligament. Cranially the lesion extends till the left subhepatic region. There is osteolysis of the inner cortex and marrow of right iliac blade with fatty atrophy of quadriceps groups of muscles.