A rare case of mixed endometrial tumor with endometroid adenocarcinoma and G2 neuroendocrine tumor: case report and literature review

ABSTRACT
Background. Neuroendocrine tumors (NETs) of the endometrium are exceptionally rare. NETs belong to a heterogeneous group of neuroendocrine neoplasms (NENs) that infrequently involve the genital tract and typically present with abnormal vaginal bleeding.
Case presentation. We report a case involving a 77-years-old woman who experienced abnormal uterine bleeding persisting for one year. Initial evaluation utilizing transvaginal ultrasound revealed an area of increased endometrial thickness, prompting further investigation. Subsequent office hysteroscopy confirmed the presence of an endometrial lesion macroscopically without signs of malignancy, necessitating a polypectomy. Histological examination of the excised polyp revealed in the first instance a G1  endometrioid carcinoma of the endometrium. Consequently, the patient underwent a total laparoscopic hysterectomy, bilateral salpingo-oophorectomy, as well as sentinel left and right external iliac node dissection. Surprisingly, the pathologic assessment of the final surgical specimen revealed an unusual mixed endometrial tumor consisting of both G2 endometrioid adenocarcinoma and G2 neuroendocrine tumor (NET, formerly known as carcinoid).
Conclusions. This specific presentation is supported by a limited number of documented cases within the current literature. The patient is currently alive, with no evidence of recurrence, and is being closely monitored, with follow-up appointments scheduled every three months.