Pang Brendan, Leong Cheng Chee, Salto-Tellez Manuel, Petersson Fredrik
Department of Pathology, National University of Singapore, Singapore.
Appl Immunohistochem Mol Morphol. 2011 Jan;19(1):70-5. doi: 10.1097/PAI.0b013e3181eec73c.
Desmoplastic small round cell tumor is a rare malignant neoplasm mostly occurring in the vicinity of or within the peritoneal cavity, and is uncommon in the head and neck region. Tumor location within a major salivary gland is exceptional. We report a case of a 41-year-old Chinese man with a history of diabetes mellitus and end-stage renal failure on peritoneal dialysis with a desmoplastic small round cell tumor occurring in the left submandibular gland. Fine-needle aspiration cytology showed variably cohesive clusters of small cells with hyperchromatic nuclei and fine granular chromatin. On histology the neoplasm displayed classic features of a desmoplastic small round cell tumor with angulated nests of small round blue cells in a fibromyxoid/desmoplastic stroma. Neoplastic cells were immunoreactive for cytokeratins (AE1/3), desmin (paranuclear dot-like), WT-1 (nuclear), epithelial membrane antigen, and CD56. EWS gene translocation and EWS-WT1 gene fusion were detected by fluorescence in situ hybridization and reverse transcriptase polymerase chain reaction, respectively. The case presented is the sixth case of and the oldest reported patient with a desmoplastic small round cell tumor occurring in a major salivary gland to date. Desmoplastic small round cell tumor should be considered in the differential diagnosis of a salivary gland neoplasm with a basaloid or small cell pattern on fine-needle aspiration cytology.
促纤维增生性小圆细胞瘤是一种罕见的恶性肿瘤，主要发生在腹膜腔附近或内部，在头颈部区域并不常见。肿瘤位于大唾液腺内的情况极为罕见。我们报告一例41岁的中国男性患者，有糖尿病病史且因终末期肾衰竭正在进行腹膜透析，其左下颌下腺发生了促纤维增生性小圆细胞瘤。细针穿刺细胞学检查显示，有不同程度聚集的小细胞团，细胞核深染，染色质呈细颗粒状。组织学检查显示，该肿瘤具有促纤维增生性小圆细胞瘤的典型特征，在纤维黏液样/促纤维增生性基质中有成角的小圆形蓝色细胞巢。肿瘤细胞对细胞角蛋白（AE1/3）、结蛋白（核旁点状）、WT-1（细胞核）、上皮膜抗原和CD56呈免疫反应阳性。分别通过荧光原位杂交和逆转录聚合酶链反应检测到EWS基因易位和EWS-WT1基因融合。该病例是迄今为止报道的第六例发生在大唾液腺的促纤维增生性小圆细胞瘤，也是年龄最大的患者。在细针穿刺细胞学检查中，对于具有基底样或小细胞模式的唾液腺肿瘤进行鉴别诊断时，应考虑促纤维增生性小圆细胞瘤。
