Small cell carcinoma of the endometrium: A clinicopathological study and management of three cases

Neuroendocrine carcinoma of the endometrium: a retrospective analysis of data from a single center

BACKGROUND

Neuroendocrine carcinoma (NEC) originating from the endometrium is rare, and there is limited knowledge regarding its diagnosis and optimal management. In this study, we present our experience with 11 patients with endometrial NEC, aiming to provide guidance for clinical practice.

METHODS

We retrospectively collected the clinical, pathological, and treatment data of 11 patients with endometrial NEC who were treated at the First Affiliated Hospital of Zhengzhou University from January 2011 to July 2023. The clinicopathological characteristics, treatment and prognosis of these patients were analyzed.

RESULTS

The median age of the patients was 55.0 (39.0-64.0) years, and the median tumor size was 40.0 (33.0-60.0) mm. Irregular vaginal bleeding was the most common symptom observed in 10 out of 11 patients, while metabolic syndrome occurred in only 2 out of 11 patients. Six out of the 11 patients were diagnosed at an early stage. Among the patients, 6 were diagnosed with endometrial NECs, while the remaining patients had a combination of endometrial NEC and other non-NEC endometrial carcinomas. All patients underwent surgery, except for one who received only chemotherapy due to multiple metastases. After surgery, adjuvant chemotherapy was administered to 5 patients, chemotherapy combined with radiotherapy was given to 3 patients, and 2 patients did not receive any adjuvant therapy. A total of 10 patients completed the follow-up, with a median follow-up time of 51.0 (14.3-81.0) months. Unfortunately, 2 patients died from the disease.

CONCLUSION

NECs originating from the endometrium might not be affected by metabolic disorders. Preoperative diagnosis of these tumors was challenging. The primary approach for managing endometrial NEC can be multimodal treatment centered around surgery.

Molecular Characterization of Neuroendocrine Carcinomas of the Endometrium: Representation in All 4 TCGA Groups

High-grade neuroendocrine carcinomas (NEC) of the endometrium are rare and account for <1% of all endometrial carcinomas. Both small cell neuroendocrine carcinoma (SCNEC) and large cell neuroendocrine carcinoma (LCNEC) morphologies have been reported. Little is known regarding the molecular features of endometrial NEC including how they compare to pulmonary NEC (the most common site for these neoplasms) and the more common endometrial carcinoma histotypes. In this study, we investigated the molecular alterations in a series of endometrial NEC using a targeted next generation sequencing panel (Oncopanel). Fourteen NEC were sequenced; pure NEC (n=4) and mixed (n=10) with endometrioid adenocarcinoma (n=9) or carcinosarcoma (n=1). The NEC components of mixed tumors comprised LCNEC (n=6) and SCNEC (n=4). The 4 pure NEC comprised LCNEC (n=2) and SCNEC (n=2). Molecular analysis classified tumors into the 4 The Cancer Genome Atlas groups: (1) POLE-mutated/ultramutated (1/14; 7%), (2) microsatellite instability/hypermutated (6/14; 43%), (3) TP53 mutated/copy number high (2/14; 14%), or (4) no specific molecular profile (5/14; 36%). Overall, 50% of cases were ultramutated or hypermutated. In 8 cases of mixed carcinomas, the different histologic components were macrodissected and separately sequenced; molecular alterations were nearly identical among the 2 components, with the non-NEC component harboring slightly increased tumor mutational burden. Only 2 carcinomas (both with pure SCNEC morphology) had a molecular profile that would be expected in typical pulmonary SCNEC (RB1 deletion and TP53 mutations). Our findings, similar to data from NECs of other anatomic sites, suggest that the molecular context may be important when selecting therapies for women with endometrial NEC. Immune checkpoint inhibition may be a reasonable approach to treatment of microsatellite instability-NEC and we thus recommend that all endometrial NEC be tested for mismatch repair abnormalities, either molecularly or by mismatch repair protein immunohistochemistry.

Mixed large and small cell neuroendocrine carcinoma of the endometrium with serous carcinoma: A case report and literature review

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.