腹部促结缔组织增生性小圆细胞肿瘤的CT、MRI表现

CT and MRI Features of Intra-abdominal Desmoplastic Small Round Cell Tumors

目的探讨腹部促结缔组织增生性小圆细胞肿瘤(desmoplastic small round cell tumor,DSRCT)的CT、MRI表现。资料与方法回顾性分析经病理证实的7例DSRCT患者的临床及影像学资料,7例中单发2例,多发5例;病灶直径>10cm者5例。7例均行CT检查,2例在1周内行MRI。结果腹、盆腔内可见分叶状或结节状低密度肿块,其内有小片状坏死,5例可见斑点状钙化;增强扫描2例轻度强化,5例中度强化;病灶与浆膜面关系密切,对周围组织及血管呈推移、包绕、侵犯倾向,但无明显起源关系,5例病灶内可见分隔状强化血管影。2例伴腔积液;2例肝转移、骨转移;3例淋巴结转移。MR T1WI上呈等低信号,T2WI呈稍高信号,其内可见更高信号的囊变坏死区。结论CT和MRI表现为腹、盆腔内巨大结节状或分叶状肿块,特别是位于膀胱后方或子宫直肠区域,与周围器官无明显起源关系,广泛腹膜、网膜种植,肿瘤呈不均匀低密度,内见斑点状钙化及小片状坏死,腹腔积液少见,增强扫描呈轻、中度强化,可考虑DSRCT的可能。

Objective To investigate the CT and MRI features of intra-abdominal desmoplastic small round cell tumors （DSRCT）. Materials and Methods Clinical and image data of 7 cases with DSRCT verified by pathology or stereotactic biopsy were analyzed retrospectively. Results There were single lesions in 2 cases and multiple nodular tumors in 5 cases. The tumor diameter was large than 10 cm in 5 cases. CT showed a large,lobulated or nodular,heterogeneous,low-attenuation mass in the abdominopelvic district with several lamellar necrotic zone in the tumors. 5 cases appeared stippled calcification in the tumors. Contrast-enhanced CT scan revealed mild or medium heterogeneous enhancement in 2 or 5 cases. Peritoneal involvement was most commonly seen The mass trended to lapse, encase and offend surrounding tissues and vessels without any obvious organ origin. 5 cases showed enhanced septative vessels in abdominopelvic tumors. 2 cases were associated with ascites. The liver and bone metastases were found in 2 cases and lymphonode metastases in 3 cases. MRI showed iso-hypotensity signal in T1WI and slightly hypertensity signal in T2WI. Cystic and necrotic zone appeared ob- vious hypertensity signal in T2WI. Conclusion Intra-abdominal DSRCT has some CT and MRI features.