Inflammatory myofibroblastic tumour of the uterus: report a case with clinical, radiological and macroscopic features resembling a uterine fibroid

Abstract

Introduction Inflammatory myofibroblastic tumour (IMT) is a histologically low-grade neoplasm of myofibroblasts and is most commonly seen in lung. Uterine IMT is a rare entity with limited number of cases reported in the literature. Case report We report a case of uterine IMT in a 65-year-old woman presenting with menorrhagia. Her ultrasound showed an intramural ‘fibroid’ 18 mm in diameter. Macroscopic examination of the uterus identified a well defined intramural pale tan rubbery lesion consistent with the ‘fibroid’ described by the ultrasound. In histological examination, this was a spindle cell lesion with bland nuclear features, rare mitoses and scattered small aggregates of mononuclear chronic inflammatory cells. The tumour cells exhibited strong widespread cytoplasmic staining with ALK-1 as well as patchy strong cytoplasmic staining with smooth muscle actin and desmin. CD34 staining was negative. The findings were consistent with an IMT. Discussion Uterine IMTs appear to behave in an indolent fashion. A constellation of morphologic and immunohistochemical features, including ALK expression, distinguishes this entity from its malignant mimics and allows for a more conservative management than dictated by uterine sarcomas. This case emphasises the significance of considering IMT as a possible differential diagnosis in a uterine lesion.