Magnetic resonance imaging of typical polypoid adenomyoma of the uterus in 8 patients: correlation with pathological findings

OBJECTIVE: To study the magnetic resonance imaging findings of typical polypoid adenomyoma and correlate radiological findings with histopathologic findings. METHODS: Magnetic resonance imaging and histopathologic findings were retrospectively reviewed in 8 patients. The size, location, polyp's shape, and signal intensity of magnetic resonance imaging findings were evaluated. RESULTS: The polyp's shape of 8 cases is pedunculated in 7 and sessile in 1, and all 8 cases are well circumscribed. Four cases (50%) show an isointense mass relative to the myometrium with small or large hyperintense foci on T1-weighted imaging (T1WI) or T2-weighted imaging (T2WI), reflecting the fascicle of smooth muscle with islands of hemorrhagic endometrial tissue. One case forms a large hemorrhagic cavity, being hyperintense on T1WI and hypointense on T2WI. Three cases (37%) show almost homogeneous isointense or hyperintense mass on T2WI. CONCLUSIONS: When there is a well-defined polypoid mass protrusion into the uterine endometrial cavity that is isointense relative to the myometrium with small or large foci of high signal on T1WI or T2WI in a premenopausal woman, typical polypoid adenomyoma can be considered in the differential diagnosis.