Endometrial carcinoma development in an endometrial polyp with early metaplastic bone formation in a young female patient

摘要

A 30-year-old nulliparous married woman presented with a 4-month history of vaginal spotting. She was not obese (height: 1.63 m; weight: 49 kg; BMI: 18.44 kg/m2) and had no history of pregnancy or hormone intake. Ultrasonographic examination showed a 3 X 2 X 1 cm protruding endometrial mass (Figure 1A). The patient subsequently underwent polypectomy. Microscopic examination revealed a mixed simple and complex hyperplasia with adenocarcinoma in situ; squamous metaplasia with morule formation; multiple cystically dilated glands and thick-walled vessels (Figure 1B-D). Some foci of osteoid formation were observed, and one of them was partially mineralised (Figure IE). Numerous entrapped osteoblasts as osteocytes were observed in the osteoids. Before the diagnosis, we had considered the possibility of an atypical polypoid adenomyofibroma of low malignant potential (APA-LMP), since the patient was young and the tumour was polypoid with proliferation of irregular glands and squamous metaplasia. However, the lesion was not confined to the polyp but had spread widely into the surrounding endometrium of the anterior wall of the uterus. Furthermore, cellular smooth muscle was not prominent. The patient was finally diagnosed with an adenocarcinoma in situ arising from an endometrial polyp (EMP).