Diffuse cystic adenomyosis simulating invasive uterine neoplasm on imaging: A postmenopausal diagnostic perplexity!

Postmenopausal bleeding (PMB) with a diffusely enlarged uterus necessitates Magnetic Resonance Imaging (MRI) to reach an accurate diagnosis. Adenomyosis, especially extensive glandular variant, is an extremely rare cause reported in a postmenopausal woman. We present a challenging case of an 81-year-old woman with PMB where preoperative MRI suggested possible invasive endometrial neoplasm. However, final histopathological evidence of the hysterectomy specimen suggested Adenomyosis with extensive glandular proliferation. The patient was a multiparous lady with controlled diabetes and hypertension (controlled on medications) and a Body Mass Index of 36 kg/m². Bimanual examination suggested a diffusely enlarged uterus corresponding to 8-10 weeks gestation. Transvaginal ultrasound (TVUS) and Contrast Enhanced (CE) MRI were performed that reported multiple cystic areas with myometrial thinning at the fundal region- suspected infiltrating endometrial neoplasm. A hysteroscopic guided endometrial biopsy was suggestive of endometrial hyperplasia. In view of concerning MRI findings, a total abdominal hysterectomy and bilateral Salpingo-oophorectomy was performed. Histopathological examination revealed Adenomyosis with extensive glandular proliferation co-existing with endometrial hyperplasia and no atypia. This case highlights an important variant of Adenomyosis that potentially mimics an invasive uterine neoplasm. There is a dearth of uniform reporting standards for Adenomyosis and rarity of this condition in postmenopausal woman posing a significant preoperative diagnostic challenge.