Imaging features of mesonephric-like adenocarcinoma of the endometrium

Mesonephric-like adenocarcinoma (MLA) is a newly classified endometrial carcinoma known for its poor prognosis, although the imaging characteristics of this tumour have yet to be reported. This study aims to clarify the imaging characteristics of MLA of the endometrium.

Imaging findings of 8 pathologically confirmed cases with MLA were retrospectively analysed. The mean patients were 65 years old (57-72) and were postmenopausal. Contrast-enhanced MR was available in all cases, including dynamic contrast enhancement (DCE) in 7. Pre- and post-contrast CT and FDG-PET/CT were performed in 6 and 2, respectively. We analysed the size, location, growth pattern, signal intensity on T1-, T2-weighted images, the pattern of enhancement on DCE and static phase, ADC, local extension on MR, density on pre-contrast CT, SUVmax on FDG-PET/CT, and metastatic diseases.

Seven of the 8 patients had an endophytic, eccentric growth pattern. The tumour location within the uterus, the signal intensity, and the density varied. However, the ADC was low, and SUVmax was high in all available cases. The enhancing pattern of the solid part was transient early in 5 and gradually in 2 of 7 patients with DCE, and a micro-honeycombing pattern was observed on the static phase in 6 of the 8 cases.

Although in a limited number of cases in a single-institute analysis, large eccentric masses within the myometrium with restricted diffusion and a micro-honeycombing pattern may be imaging characteristics of MLA.

This is the first manuscript describing the imaging features of MLA.