Maryam Fatima, Ahmareen Khalid Sheikh and Ashok Kumar Tanwani
Department of Pathology, Pakistan Institute of Medical Science, Islamabad, Pakistan
Introduction: Myelolipomas are benign tumors composed of mature adipose tissue and normal hematopoietic cells. Myelolipomas develop in older age group and usual site of occurrence is adrenal gland. Their development in young individuals and at extra-adrenal site is quite rare. Very few cases of extra-adrenal myelolipomas have
been reported in the literature. An extra-adrenal myelolipoma is solitary, well defined mass in abdomen, commonly occurring in retroperitoneal area. The small sized lesions are usually asymptomatic, but if large in size they can produce symptoms related to mass effect. The patient has no hematological abnormalities.
Case Presentation: We present a case of a large intra abdominal extra-adrenal myelolipoma measuring 28 x 22 x 6cm in a 29 years old male patient who presented with abdominal pain and distention. His abdominal CT scan showed a large well defined retroperitoneal lesion measuring 13.1 x 10.3 x 22cm in Anteroposterior xTransverse x
Craniocaudal extent, in the region of left paraventricular gutter having fat density may represent liposarcoma. His both adrenals appeared normal. He was operated for this lesion and the specimen was sent to us for histopathological evaluation. Grossly it was solitary, encapsulated mass. Cut section showed fatty tissue with hemorrhagic
areas. Microscopically, mature adipose tissue with areas of mature hematopoietic cell of all lineages was seen.
Conclusion: Since extra-adrenal myelolipoma is a rare entity diagnosis of this lesion based on radiographic studies
alone is at times difficult. It is important to distinguish extra-adrenal myelolipoma from other fat-containing tumors in particular retroperitoneal liposarcoma, extra-medullary hematopoietic neoplasms and angiomyolipoma. Histopathologic evaluation is the gold standard for confirmation of the diagnosis. We have discussed the
background, pathology, complications, differential diagnosis and management of this rare entity.
Keywords: Myelolipoma, Extraadrenal myelolipoma, Hematopoietic neoplasm.