Well-differentiated/dedifferentiated liposarcoma associated with myxoid-like morphology: a clinicopathological and molecular genetic characteristics analysis of 34 cases
10.3760/cma.j.cn112151-20231025-00302
- VernacularTitle:具有黏液样变的高分化/去分化脂肪肉瘤34例临床病理及分子遗传学特征分析
- Author:
Shuang XUE
1
;
Qiuyu LIU
;
Xiangnan GOU
;
Yuewu ZHAO
;
Qiong CHENG
;
Lingfei KONG
Author Information
1. 河南省人民医院 郑州大学人民医院病理科，郑州 450003
- Keywords:
Soft tissue neoplasms;
Liposarcoma, myxoid;
Gene amplification
- From:
Chinese Journal of Pathology
2024;53(2):168-173
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinicopathological and molecular genetic characteristics of well-differentiated/dedifferentiated liposarcoma (WDLPS/DDLPS) with myxoid-like morphology, and to distinguish them from myxofibrosarcoma (MFS) with similar morphology.Methods:Twenty-nine cases of myxoid-like liposarcoma and 5 cases of MFS were collected from Henan Provincial People′s Hospital, Zhengzhou, China and the First Medical Center of PLA General Hospital, Beijing, China from January 2015 to March 2023. Relevant markers were detected using immunohistochemistry and fluorescence in situ hybridization (FISH). The literature was also reviewed.Results:There were 24 males and 10 females, with ages ranging from 41 to 73 years. The tumor sites included retroperitoneum ( n=17), abdomen ( n=9), lower limbs ( n=5), scrotum ( n=1), upper limb ( n=1) and axilla ( n=1). WDLPS was commonly seen as lipomatoid type (12 cases), while the dedifferentiated components of DDLPS included low-grade (13 cases) and high-grade (2 cases) morphology, with low-high grade myxofibrosarcoma, dermatofibrosarcoma protuberans, and low-grade fibrosarcoma structures. Twenty-nine liposarcomas had various proportions of myxoid-like morphology, while 16 showed various degrees of tumor necrosis. The myxoid-like component showed myxoid pleomorphic liposarcoma (MLPS)-like morphology, lobulated growth, characteristic slender, ramified capillary network,"chicken claw-like"morphology, mucus-rich stroma and lung edema-like morphology. Tumor cells were spindle and oval, with many variable vacuolar lipoblasts. MDM2 gene amplification was detected using FISH and present in all tested cases (29/29). DDIT3 break-apart mutation was not detected, but its cluster amplification was present (24/29). Among the MFS cases, one showed cluster amplification (1/5), but no cases showed break-apart or amplification of MDM2 gene. Conclusions:WDLPS/DDLPS with myxoid-like morphology is most commonly seen in the retroperitoneum and abdominal cavity and mostly harbors DDIT3 break-apart probe amplification, while this amplification is not specific to liposarcoma. For core biopsy specimens or very rare tumors in the limbs, when histology has mucinous stroma and MLPS-like morphology, misdiagnosis of MLPS or other non-lipomatous neoplasms with myxoid morphology should be avoided.
