Uchihashi Kazuyoshi, Matsuyama Atsuji, Shiba Eisuke, Kimura Yoshizo, Ogata Toshiro, Yabuki Kei, Harada Hiroshi, Kubo Chisachi, Tsuda Yojiro, Jotatsu Mao, Hisaoka Masanori
Department of Pathology & Oncology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Department of Pathology, St. Mary's Hospital, Kurume, Japan.
Pathol Int. 2017 May;67(5):264-268. doi: 10.1111/pin.12525. Epub 2017 Mar 23.
Prominent cyst formation is an unusual feature of liposarcoma. We report here a case of dedifferentiated liposarcoma with huge cystic change without preoperative chemo- or radiation therapy. The lesion arose in the retroperitoneum juxtaposed to the right kidney of a 67-year-old woman. She underwent a surgical removal of the retroperitoneal cyst. The cystic tumor contained 1600 mL of old bloody fluid, and its wall was composed of edematous, inflamed or sclerosing fibrous tissue with fatty tissue containing abundant atypical stromal cells, which were immunohistochemically positive for MDM2 and CDK4, and demonstrated MDM2 gene amplification by fluorescence in situ hybridization. The wall was contiguous to an atypical lipomatous nodule located in the mesentery. The following surgical specimens of the right hemicolectomy and right nephrectomy revealed atypical cells infiltrating into the subserosa of the colon and the perirenal fat tissue or that in the renal sinus. This case indicates that well differentiated or dedifferentiated liposarcoma should be also considered as a differential diagnosis of perirenal cystic mass.
显著的囊肿形成是脂肪肉瘤的一个不寻常特征。我们在此报告一例未接受术前化疗或放疗的去分化脂肪肉瘤伴巨大囊性变的病例。该病变发生于一名67岁女性右肾旁的腹膜后。她接受了腹膜后囊肿的手术切除。囊性肿瘤内含有1600毫升陈旧性血性液体，其壁由水肿、炎症或硬化的纤维组织组成，伴有含丰富非典型间质细胞的脂肪组织，这些细胞MDM2和CDK4免疫组化呈阳性，并通过荧光原位杂交显示MDM2基因扩增。该壁与位于肠系膜的非典型脂肪瘤性结节相连。随后右半结肠切除术和右肾切除术的手术标本显示非典型细胞浸润至结肠浆膜下层和肾周脂肪组织或肾窦。该病例表明，高分化或去分化脂肪肉瘤也应被视为肾周囊性肿块的鉴别诊断之一。
