Female reproductive tract inflammatory myofibroblastic tumor (IMT): A comprehensive analysis of clinicopathological and genomic features in a case series, including the identification of SERPINE1-ALK fusion in the fallopian tube.

Abstract

Inflammatory myofibroblastic tumors (IMTs) of the female reproductive tract are rare neoplasms, predominantly originating in the uterus, but can occasionally be identified in other locations. This retrospective study included 15 cases from six hospitals in China between 2017 and 2024, comprising 14 cases involving the uterus and one involving a fallopian tube. DNA and RNA next-generation sequencing (NGS) was conducted on all samples. The age of onset ranged from 34 to 54 years, with a median of 41 years and a mean of 42.40 ± 1.32 years. Tumor sizes varied from 2.9 cm to 10.0 cm, with a median size of 6.00 cm and a mean size of 5.90 ± 0.45 cm. RNA sequencing demonstrated ALK rearrangements with either identical or distinct fusion partners in individual cases, including a new partner, SERPINE1, detected in the case involving the fallopian tube. DNA sequencing revealed that 46.7 % (7/15) of the cases exhibited additional gene mutations, including one case with a TP53 mutation that had been previously reported and subsequently developed metastasis within a few months. ALK rearrangement remains the primary driver gene and therapeutic target for this type of tumor. From the perspective of predicting tumor biology, genetic variations at the DNA level, in addition to clinicopathological parameters, are equally significant and may provide a critical foundation for prognosis.