MRI Findings of Uterine Adenofibroma With Squamous Metaplasia

Uterine adenofibroma is an extremely rare, benign, mixed epithelial and mesenchymal tumor, and its imaging characteristics remain poorly characterized because only a small number of cases have been reported. Accurate preoperative diagnosis can be difficult, as the clinical and radiological features of uterine adenofibroma often overlap with those of endometrial carcinoma, adenosarcoma, and other lesions of the endometrial cavity. Very few studies have documented detailed MRI findings, and further case reports are needed to establish distinctive imaging patterns. We report the case of an 84-year-old woman who presented with genital bleeding and a uterine mass on imaging. MRI revealed a mainly solid tumor with small cystic components occupying the endometrial cavity. Dynamic contrast-enhanced MRI demonstrated linear surface enhancement in the early phase and papillary projections with gradually increasing enhancement in the delayed phase. These imaging findings were consistent with the histopathological features of the tumor, which showed surface papillations and widespread squamous metaplasia. The presence of prominent squamous metaplasia likely contributed to the marked and progressive surface enhancement, a feature that distinguished this case from previously reported adenofibromas. This report highlights the importance of recognizing unique MRI characteristics, particularly papillary surface enhancement patterns, when evaluating endometrial cavity tumors. Further accumulation of imaging-pathology correlated reports may assist in improving the diagnostic accuracy of this rare tumor type.