RESUMEN
RATIONALE: Endometrial neuroendocrine carcinoma is a rare histological subtype of endometrial cancer, divided into low-grade neuroendocrine carcinoma (carcinoid) and high-grade neuroendocrine carcinoma (small cell and large cell neuroendocrine carcinoma). It is characterized by high invasiveness and poor prognosis. L/SCNEC is an extremely rare pathological type of endometrial carcinoma, and the number of reports on this condition is few globally. PATIENT CONCERNS: A 54-year-old Chinese female presented with vaginal bleeding. DIAGNOSES: Outpatient hysteroscopy and endometrial biopsy were performed, and the pathological examination revealed that cervix was invaded by endometrial malignancy. The patient underwent a laparoscopic radical hysterectomy was diagnosed with the mixed large and small cell neuroendocrine carcinoma (L/SCNEC) of the endometrium combined with serous carcinoma III C2 (FIGO2009). INTERVENTIONS: Chemotherapy-radiotherapy-chemotherapy "sandwich" treatment was performed as postoperative therapy. OUTCOMES: After three chemotherapy circles, the patient showed no evidence of further disease progression. LESSONS: L/SCNEC is a rare and invasive disease. Once diagnosed, comprehensive treatments including surgery, radiotherapy, and chemotherapy can prolong the survival of patients and improve the prognosis.