Extraskeletal Ewing’s Sarcoma in Diverse Anatomical Sites

Abstract Ewing’s sarcoma (ES), part of the ES family of tumors (ESFTs), is the second most common childhood bone tumor. However, extraskeletal ES (EES) is rare. It affects soft tissues and other nonosseous sites, including the chest wall, skin, gastrointestinal tract, kidney, female genital tract, and central nervous system (CNS). EES is the rarest form in young adults’ soft tissue and extraskeletal sites. ESFTs exhibit monomorphic small, round blue cell morphology, often with Homer–Wright rosettes. Immunohistochemistry (IHC) profiling helps differentiate EES from other small, round cell tumors. Here, we present three cases of EES arising in the ovary, kidney, and CNS, emphasizing histopathology, IHC findings, and diagnostic challenges. This case series highlights that any mass lesions with small, blue round cell morphology in a diverse anatomical site, EES should be one of the main differential to consider and confirmed with IHC as its prognosis is much better than skeletal ES and early interventions drastically improves patient prognosis.