增生性小圓細胞腫瘤是一種極為少見、進展快速的惡性腫瘤，好發於男青少年及年輕成人，由於此腫瘤具有嗜葡萄糖的特性，因此F-18-氟化去氧葡萄糖正子斷層掃描/電腦斷層掃描在治療前偵測及治療後療效評估均扮演重要角色。先前報告顯示：此腫瘤的正子斷層掃描大部分都只是腹及骨盆腔的局部淋巴侵犯，我們報告一位患有此腫瘤的年輕男性病人，復發時的正子斷層掃描影像呈現罕見的全身廣泛淋巴侵犯，代表這個腫瘤有不尋常的快速進展模式，尚有許多不解之處。

Desmoplastic small round cell tumor (DSRCT) is a very rare and an aggressive malignant tumor of the small round blue cell tumor family that mainly affects male adolescents and young adults. Due to its glucose hypermetabolism nature, fluorine-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography with computed tomography (PET/CT) scan has been shown useful in the pre-treatment survey and post-treatment response evaluation. Most commonly reported PET/CT scan findings are hypermetaboilc lesions in the abdominopelvic cavity with regional lymphadenopathy. Here we report a young male patient with recurrent DSRCT, which manifested as widespread lymph node involvement. This case showed an uncommon pattern of DSRCT progression on F-18-FDG PET/CT scan and entailed that much is left to know about this disease.