<unk>  is an extremely rare, highly aggressive, and malignant neoplasm initially reported by Gerald and Rosai in 1989. The pathogenesis or histogenesis of<unk>  is uncertain; it mainly occurs in adolescents and mostly involves the abdominal and/or pelvic peritoneum. Moreover, it was also reported in epididymis, pleura, soft tissues, bone, ovary, and kidney. The diagnosis can be confirmed by histological and immunohistochemistry studies. CT scan is the most widely used diagnostic modality; abdominopelvic site was the commonest presentation and the disease can occur at other nonserosal surfaces also. Despite multimodality treatments, optimal treatment strategies remain controversial and the prognosis is poor. Current multimodality treatment rarely achieves cure and prolongs life. Here, we described 12 cases of abdominal<unk>  and retrospectively analyzed its clinical, radiological, and biopathological features, highlighting the modalities of treatment
Desmoplastic small round cell tumor
Adenomatoid tumor
Reticulum cell sarcoma
Mycetoma
Signet ring cell carcinoma
Gastrointestinal stromal tumor
Epithelioid sarcoma
Oncocytoma