Fine needle aspiration diagnosis of extraadrenal myelolipoma presenting asa pleural mass - A case report

BACKGROUND: Myelolipoma is a benign tumor composed of mature adipose tissue and hematopoietic cells. Although they are commonly found in adrenal gland s, extraadrenal myelolipomas (EMLs) are rare but well documented. They have been found in various sites, including mediastinum, liver, stomach, lungs, pelvis, spleen, retroperitoneum, presacral region and mesentery. EMLs must be distinguished from extramedullary hematopoieses, which are also compose d of hematopoietic elements but may lack adipose tissue and are associated with anemia and marked bone marrow hyperplasia. CASE: We describe a case of a pleura-based, extraadrenal myelolipoma in a 5 3-year-old female with unremarkable bone marrow findings that were initiall y encountered on fluoroscopy-guided fine needle aspiration (FNA). One year later the mass was removed via open thoracotomy. It showed typical EML feat ures histologically. CONCLUSION: EML manifests on aspiration cytology as a cellular specimen wit h numerous trilineage hematopoietic cells and a variable proportion of matu re adipose cells. To our knowledge, FNA cytology of EML has not been found in this location before. Aspiration biopsy offers a simple and reliable met hod for the diagnosis of EML in the presence of appropriate clinical settin gs.