Cystic adenomyosis with florid glandular differentiation mimicking ovarian malignancy.

We report a case of cystic adenomyosis, presenting as a huge exophytic cystic mass with florid glandular differentiation. MR findings of the mass mimicked ovarian carcinoma associated with endometriosis. The presence of signal voids bridging the uterus and tumour should suggest a mass of uterine origin. Hyperintense protuberance in a hypointense loculus on T(2) weighted images may suggest benign disease. However, surgical exploration and resection is still required to exclude an ovarian malignancy.