Uterus inflammatory myofibroblastic tumor: a clinicopathological and molecular analysis of four cases
10.3760/cma.j.cn112151-20250122-00056
- VernacularTitle:子宫炎性肌纤维母细胞瘤4例临床病理及分子遗传学特征
- Author:
Jinyi MENG
1
;
Can YIN
;
Xingjie YANG
;
Xiaohua SHI
Author Information
1. 中国医学科学院 北京协和医学院 北京协和医院病理科，北京 100730
- Publication Type:Journal Article
- Keywords:
Uterine neoplasms;
Immunohistochemistry;
Sequence analysis, RNA;
Uterus inflammatory myofibroblastic tumor
- From:
Chinese Journal of Pathology
2025;54(8):819-824
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the clinical manifestations, histological features, immunophenotype, molecular characteristics, and treatments of uterine inflammatory myofibroblastic tumor (UIMT).Methods:Clinical and pathological data of 4 UIMT cases diagnosed at the Peking Union Medical College Hospital, Beijing, China from 2020 to 2024 were collected. Their clinicopathological and genetic characteristics were analyzed.Results:The patients′ ages were 63, 42, 53 and 37 years, respectively. The tumors were located in the submucosa and intermuscular walls of the uterus, with a diameter ranging from 1.5 to 6.0 cm. All tumors were suspected by the clinician as leiomyosarcoma. Histologically, 3 of the 4 tumors showed spindle cells that appeared like leiomyoma. Prominent myxoid stroma and inflammatory cells infiltration were observed, with mitotic figures of 1-2 per 10 high-power fields. One case was primarily composed of spindle cells arranged in fascicles, with inflammatory cell infiltration, inconspicuous myxoid stroma and mitotic figures of 3 per 10 high-power fields. Two cases exhibited a pushing pattern of invasion and slightly unclear boundaries, while the other two showed infiltrative growth with unclear boundaries. The immunohistochemistry revealed diffuse and strong, cytoplasmic granular staining of ALK in all 4 cases. RNA sequencing was performed in 3 cases, of which 2 cases showed ALK gene rearrangements, and 1 case did not. One case underwent FISH testing and showed ALK gene translocation. Follow-up showed that no recurrence or metastasis was observed after surgery in all patients.Conclusions:UIMT is a rare mesenchymal tumor of the uterus and lacks specific clinical manifestations. When tumor cells exhibit mild atypia, indistinct borders, myxoid stroma, inflammatory cell infiltration, and decreased expression of ER and PR on immunohistochemistry, immunohistochemical staining of ALK is recommended to confirm the diagnosis of UIMT. This tumor shares many features with myogenic tumors and endometrial stromal sarcomas. Molecular testing may also be needed to assist in diagnosis when necessary. For patients who are not suitable for surgery or have recurrence and metastasis, targeted therapy with ALK inhibitors can be used.
