A Case Report of the Synchronous Occurrence of Ovarian Granulosa Cell Tumour and Malignant Endometrial Polyp with Immunohistochemical Expression of Hormone Receptors and Biomarkers p-53 and Ki-67

<b>Background and Clinical Significance:</b> Abnormal uterine bleeding during the postmenopausal years is a pathological sign that may be due to simultaneous intrauterine and ovarian pathology. Granulosa cell tumours of the ovary are malignant neoplasms producing oestradiol, which leads to the abnormal proliferation of the endometrium, precancerous lesions, and endometrial carcinoma type I. <b>Case Presentation:</b> The authors present a clinical case of a 67-year-old woman with postmenopausal bleeding who underwent a total abdominal hysterectomy with bilateral adnexectomy, pelvic lymphadenectomy, and partial omentectomy. The histopathological examination showed a granulosa cell adult-type ovarian tumour and a malignant endometrial polyp with atypical hyperplasia of the endometrium. <b>Conclusions:</b> The immunohistochemical analysis of the malignant endometrial polyp confirmed the expression of oestrogen, progesterone receptors, and the biomarker Ki-67.