Primary Ewing sarcoma of the mesentery: An extremely uncommon case

Abstract

Ewing sarcoma usually arises in the bones of children. Extra-skeletal Ewing sarcoma commonly occurs in soft tissue and rarely involves other organs of the body. The mesentery besides the intestine is an extremely uncommon location. The diagnosis poses a challenge as other malignant small round cell tumors come in the differential diagnosis in this location. Early histopathological diagnosis and immunohistochemical confirmation are crucial to outline an appropriate treatment plan. Expression of membranous CD99 and nuclear FLI-1 and NKX2.2 are fairly specific for diagnosis. The molecular study is reserved for difficult cases. Prognosis is poor in an extra-skeletal location in older individuals.

Keywords

• ewing sarcoma
• extra-skeletal
• mesentery
• cd99
• nkx2.2