Department of Pathology, Koc University School of Medicine, Topkapi, 34010, Istanbul, Turkey.
Department of Pathology, Ondokuz Mayis University School of Medicine, Samsun, Turkey.
Diagn Pathol. 2020 Jul 23;15(1):95. doi: 10.1186/s13000-020-01015-w.
Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive neoplasm seen in children and young adults, usually manifested by involvement of abdominal serosa. Here, we present an unusual case of primary DSRCT of kidney.
The patient was an 8-year-old girl with a large renal mass which was confused with primitive neuroectodermal tumor (PNET) in the needle biopsy. The tumor had a variegated histology revealing frequent pseudo-rosette formations, pseudopapillary architecture, rhabdoid, clear or pleomorphic cells in addition to typical small round cell morphology and desmoplasia. It showed immunohistochemical features of DSRCT, and EWSR1 re-arrangement.
Proffering this diagnosis is particularly difficult for tumors of viscera because of the incognizance of the entity in these locations. Moreover, DSRCT is a great mimicker and may get easily confused with more common kidney malignancies of childhood such as Wilms tumor, PNET/EWS, rhabdoid tumor, clear cell sarcoma, and other small round cell tumors as well as renal cell carcinomas. The distinction is critical as the accurate therapeutic approach will require correct diagnosis.
促结缔组织增生性小圆细胞肿瘤（DSRCT）是一种罕见的、侵袭性的儿童和成人群体肿瘤，通常表现为腹腔浆膜受累。在此，我们报告一例肾脏原发性 DSRCT 的不典型病例。
患者为 8 岁女孩，有一巨大肾肿块，在针吸活检时与原始神经外胚层肿瘤（PNET）相混淆。肿瘤的组织学形态多样，频繁出现假菊形团形成、假乳头结构、横纹肌样、透明或多形性细胞，除了典型的小圆细胞形态和促结缔组织增生外。它还表现出 DSRCT 的免疫组织化学特征和 EWSR1 重排。
由于在这些部位对该实体缺乏认识，对于内脏肿瘤来说，提出这一诊断特别困难。此外，DSRCT 是一种高度模拟物，可能很容易与儿童更常见的肾脏恶性肿瘤相混淆，如肾母细胞瘤、PNET/EWS、横纹肌样瘤、透明细胞肉瘤和其他小圆细胞肿瘤以及肾细胞癌。这种鉴别非常重要，因为准确的治疗方法需要正确的诊断。
