Clinical Outcomes of Small Cell Carcinoma of the Genitourinary Tract and the Prognostic Significance of the Tumor Immune Microenvironment.

PURPOSE: Small cell carcinoma of the genitourinary tract (GU SCC) is a rare disease with a poor prognosis. There are only limited treatment options due to insufficient understanding of the disease. In this study, we analyzed the clinical outcomes of patients with GU SCC and their association with the tumor immune phenotype. MATERIALS AND METHODS: Patients diagnosed with GU SCC were included. Survival outcomes according to the primary location (prostate and non-prostate) and stages (limited disease [LD] and extensive disease [ED]) were analyzed. We performed multiplex immunohistochemistry (IHC) in non-prostate SCC patients and analyzed the immune cell population. RESULTS: A total of 77 patients were included in this study. Their median age was 71 years, 67 patients (87.0%) were male, and 48 patients (62.3%) had non-prostate SCC. All patients with ED (n=31, 40.3%) received etoposide plus platinum (EP) as initial treatment and median overall survival (OS) was 9.7 months (95% confidence interval [CI], 7.1 to 18.6). Patients with LD (n=46, 59.7%) received EP followed by radiotherapy or surgery, and 24-months OS rate was 63.6% (95% CI, 49.9 to 81.0). The multiplex IHC analysis of 21 patients with non-prostate SCC showed that patients with a higher density of programmed death-ligand 1-expressing CD68+CD206+ M2-like macrophages had significantly worse OS outcomes with an adjusted hazards ratio of 4.17 (95% CI, 1.25 to 14.29; adjusted p=0.02). CONCLUSION: Patients with GU SCC had a poor prognosis, even those with localized disease. The tumor immune phenotypes were significantly associated with survival. This finding provides new insights for treating GU SCC.

Clonal Origin and Lineage Ambiguity in Mixed Neuroendocrine Carcinoma of the Uterine Cervix.

Small-cell neuroendocrine carcinoma (SCNEC) of the cervix is a rare disease characterized by a high incidence of mixed tumors with other types of cancer. The mechanism underlying this mixed phenotype is not well understood. This study established a panel of organoid lines from patients with SCNEC of the cervix and ultimately focused on one line, which retained a mixed tumor phenotype, both in vitro and in vivo. Histologically, both organoids and xenograft tumors showed distinct differentiation into either SCNEC or adenocarcinoma in some regions and ambiguous differentiation in others. Tracking single cells indicated the existence of cells with bipotential differentiation toward SCNEC and adenocarcinomas. Single-cell transcriptional analysis identified three distinct clusters: SCNEC-like, adenocarcinoma-like, and a cluster lacking specific differentiation markers. The expression of neuroendocrine markers was enriched in the SCNEC-like cluster but not exclusively. Human papillomavirus 18 E6 was enriched in the SCNEC-like cluster, which showed higher proliferation and lower levels of the p53 pathway. After treatment with anticancer drugs, the expression of adenocarcinoma markers increased, whereas that of SCNEC decreased. Using a reporter system for keratin 19 expression, changes in the differentiation of each cell were shown to be associated with the shift in differentiation induced by drug treatment. These data suggest that mixed SCNEC/cervical tumors have a clonal origin and are characterized by an ambiguous and flexible differentiation state.

Clinical characteristics and prognosis of primary small cell carcinoma of the breast: a propensity score-matched, population-based study.

OBJECTIVE: The purpose of this study was to describe the clinicopathological characteristics and prognosis of primary small cell carcinoma of the breast (PSCCB) and compare PSCCB with breast invasive ductal carcinoma (IDC). DESIGN: A retrospective cohort study. SETTING: Data of patients with PSCCB and breast IDC were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2016. PARTICIPANTS: Eighty-three patients with PSCCB and 410 699 patients with breast IDC were enrolled in the present cohort study. MATERIALS AND METHODS: Patients with PSCCB and breast IDC were identified from the SEER database between 2004 and 2016. The clinicopathological characteristics and survival of patients with PSCCB and IDC were compared. Propensity score matching (PSM) analysis was performed to adjust for differences in baseline characteristics when comparing overall survival (OS) and cancer-specific survival (CSS). Moreover, OS-/CSS-specific nomograms were established to predict the prognosis of PSCCB. RESULTS: Compared with IDC, PSCCB was significantly correlated with older age, male, higher pathological grade, higher TNM (tumour, node, metastases) stage, a higher proportion of triple-negative breast cancer, a lower proportion of ER/PR positivity and significantly worse clinical outcome. The median OS and CSS of patients with PSCCB were 23.0 m (95%CI 13.0 to 56.0) and 28.0 m (95%CI 18.0 to 66.0), respectively. The 5-year OS and CSS rates in the PSCCB group were 36.1% and 42.4%, respectively. In the matched cohort after PSM analysis, patients with PSCCB had significantly worse OS and CSS than IDC patients. Multivariate Cox regression analysis demonstrated that T stage and administration of chemotherapy were independent prognostic factors for both OS and CSS in patients with PSCCB. The C-index for OS-/CSS-specific nomogram was 0.75 (95%CI 0.66 to 0.85)/0.79 (95%CI 0.69 to 0.89), respectively. The calibration curve in the ROC analysis indicated that the predicted value was consistent with the actual observation value. Decision curve analysis suggested that the nomogram model has a significant positive net benefit from the risk of death and are better than the traditional TNM staging system. CONCLUSION: PSCCB has distinct clinicopathological characteristics, and patients with PSCCB have significantly worse clinical outcomes than those with IDC.

Case series of ovarian neuroendocrine carcinoma: overview of clinicopathological features.

BACKGROUND: Ovarian neuroendocrine carcinoma (O-NEC) is a relatively uncommon neoplasm, and the current knowledge regarding its diagnosis and management is limited. In this series, our objective was to provide an overview of the clinicopathological characteristics of the disease by analyzing clinical case data to establish a theoretical foundation for the diagnosis and management of O-NEC. CASE PRESENTATION: We included three patients in the present case series, all of whom were diagnosed with primary O-NEC based on pathomorphological observation and immunohistochemistry. Patient 1 was a 62-year-old patient diagnosed with small cell carcinoma (SCC) of the pulmonary type. Post-surgery, the patient was diagnosed with stage II SCC of the ovary and underwent standardized chemotherapy; however, imaging examinations conducted at the 16-month follow-up revealed the existence of lymph node metastasis. Unfortunately, she passed away 21 months after the surgery. The other two patients were diagnosed with carcinoid tumors, one at age 39 and the other at age 71. Post-surgery, patient 2 was diagnosed with a carcinoid in the left ovary, whereas patient 3 was diagnosed with a carcinoid in her right ovary based on clinical evaluation. Neither of the cases received adjuvant therapy following surgery; however, they have both survived for 9 and 10 years, respectively, as of date. CONCLUSION: Primary O-NECs are rare and of diverse histological types, each of which has its own unique biological features and prognosis. SCC is a neoplasm characterized by high malignancy and a poor prognosis, whereas carcinoid tumors are of lesser malignancy and have a more favorable prognosis.

Population-Based Survival Analysis of Stage IVB Small-Cell Neuroendocrine Carcinoma in Comparison to Major Histological Subtypes of Cervical Cancer.

The aim of the current study is to investigate the survival outcome of stage IVB SCNEC of the uterine cervix in comparison to major histological subtypes of cervical cancer. A population-based retrospective cohort study was conducted using the Osaka Cancer Registry data from 1994 to 2018. All FIGO 2009 stage IVB cervical cancer patients who displayed squamous cell carcinoma (SCC), adenocarcinoma (A), adenosquamous cell carcinoma (AS), or small-cell neuroendocrine carcinoma (SCNEC) were first identified. The patients were classified into groups according to the types of primary treatment. Then, their survival rates were examined using the Kaplan-Meier method. Overall, in a total of 1158 patients, clearly differential survival rates were observed according to the histological subtypes, and SCNEC was associated with shortest survival. When examined according to the types of primary treatments, SCNEC was associated with significantly decreased survival when compared to SCC or A/AS, except for those treated with surgery. In patients with FIGO 2009 stage IVB cervical cancer, SCNEC was associated with decreased survival when compared to SCC or A/AS. Although current treatments with either surgery, chemotherapy or radiotherapy have some therapeutic efficacies, to improve the prognosis, novel effective treatments specifically targeting cervical SCNEC need to be developed.

Pathologic collision of urinary bladder urothelial carcinoma with small cell carcinoma: a case report.

BACKGROUND: Urothelial carcinoma is a major subtype of bladder cancer and small cell carcinoma (SCC) is a rare type of cancer in clinical practice. Pathologic collision of urinary bladder urothelial carcinoma with SCC is not common in clinical settings. CASE PRESENTATION: Here, we report a patient with high-grade papillary carcinoma which changed to collision tumor with SCC. The patient underwent radical cystectomy; however, neck and mediastinum lymph nodes metastases were detected 11 months after the operation. The lymph nodes were diagnosed pathologically as SCC. Chemoradiotherapy was subsequently prescribed. Unfortunately, this patient died of COVID-19 in early 2023. DISCUSSION: We hypothesized the mechanism underlying this pathological transformation. For patients with urothelial bladder cancer, pathological analysis should be conducted to allow standardized and persistent treatment. Moreover, drugs should be selected depending on the type of pathology, especially for patients who develop relapse, since collision tumor or other pathological tumors may be present. CONCLUSIONS: We recommend that radical cystectomy be performed early enough for patients with non-muscle invasive bladder cancer, who are at a high risk of tumor recurrence. However, this conclusion needs to be validated in a larger number of patients.

Unusual histomorphological spectrum of urinary bladder cancers and their treatment modalities revisited: Our experience with series of five cases.

Background: Urinary bladder cancer is the eighth-most frequent carcinoma in men, commonly occurs in elderly male. Major risk factors are smoking, chronic cystitis, urinary stones. The most common histologic variant of bladder cancer is urothelial carcinoma (UC), but certain variants are unusual yet aggressive for which there is no consensus guideline of therapy. Those entities include neuroendocrine tumors both primary and metastatic, squamous cell carcinoma, and sarcomatoid carcinoma. Neuroendocrine tumors comprise carcinoid, small-cell carcinoma, and large-cell carcinoma. Aim: The present study is undertaken to highlight certain biological features of these unusual aggressive histological forms of bladder carcinoma and their recent treatment modality to prevent recurrence, metastasis, upgrading of tumor stage, and enable surprisingly complete remission. Methods: This piece of hospital-based perspective study was done from June 2018 to May 2020. Both transurethral resection of bladder tumor and cystectomy surgical samples of the symptomatic patients were collected from the urology department of our institute along with demographic data. Then processed, stained in both routine H and E stain and immunohistochemical stains (Immunohistochemistry [IHC]) like PanCK, NSE, synaptophysin, chromogranin, etc. Results: Total number of bladder cancer encountered was 42 cases; of these five rare variants were observed, i.e., one case each of primary and secondary small cell neuroendocrine carcinoma, one large cell carcinoma, one squamous cell carcinoma (SCC), and one case of sarcomatoid carcinoma. Histomorphology with IHC conferred the diagnosis then multimodality therapy (neoadjuvant/radiotherapy/surgery) was installed and followed up. Conclusion: The unconventional forms of UC can be easily diagnosed by histomorphology and can have better survival with the help of the recent multimodal treatment approach.

Metastatic Small Cell Carcinoma of a Male Breast: A Case Report and Review of the Literature.

Neuroendocrine breast cancers are rare tumors that were recognized as a distinct entity by WHO classification in 2003. It is much rarer in male breast cancer. Diagnosis is based on immunochemical analysis in which the expression of at least one neuroendocrine marker is required, associated with the exclusion of another primary site of the tumor. These tumors have a worse long-term outcome compared to other breast cancers. Small cell carcinoma of the breast is a high-grade subtype, presents with more advanced disease, and has a poorer prognosis compared with other neuroendocrine breast subtypes. A proper therapeutic strategy is still not well established. In the herein reported case, a 62-year-old male patient was diagnosed with small cell neuroendocrine carcinoma of the breast, metastatic to the liver, lung, bone and lymph node, and was treated with a first-line Platinum-Etoposide chemotherapy combination with a good clinical and radiological response. Only four previous cases of male small cell breast carcinoma were reported. Keywords: Neuroendocrine Breast Carcinoma, Small Cell Carcinoma, Diagnosis, Prognosis, Treatment.

The prognosis of patients with small cell carcinoma of the cervix: a retrospective study of the SEER database and a Chinese multicentre registry.

BACKGROUND: Small cell carcinoma of the cervix is a rare but poor prognosis pathological type of cervical cancer, for which advice in clinical guidelines is unspecific. We therefore aimed to investigate the factors and treatment methods that affect the prognosis of patients with small cell carcinoma of the cervix. METHODS: In this retrospective study, we collected data from the Surveillance, Epidemiology, and End Results (SEER) 18 registries cohort and a Chinese multi-institutional registry. The SEER cohort included females diagnosed with small cell carcinoma of the cervix between Jan 1, 2000, and Dec 31, 2018, whereas the Chinese cohort included women diagnosed between Jun 1, 2006, and April 30, 2022. In both cohorts, eligibility was limited to female patients older than 20 years with a confirmed diagnosis of small cell carcinoma of the cervix. Participants who were lost to follow-up or those for whom small cell carcinoma of the cervix was not the primary malignant tumour were excluded from the multi-institutional registry, and those with an unknown surgery status (in addition to those for whom small cell carcinoma of the cervix was not the primary malignant tumour) were excluded from the SEER data. The primary outcome of this study was overall survival (length of time from the date of first diagnosis until the date of death from any cause, or the last follow-up). Kaplan-Meier analysis, propensity score matching, and Cox-regression analyses were used to assess treatment outcomes and risk factors. FINDINGS: 1288 participants were included in the study; 610 in the SEER cohort and 678 in the Chinese cohort. Both univariable and multivariable Cox regression analysis (SEER hazard ratio [HR] 0·65 [95% CI 0·48-0·88], p=0·0058; China HR 0·53 [0·37-0·76], p=0·0005) showed that surgery was associated with a better prognosis. In subgroup analyses, surgery remained a protective factor for patients with locally advanced disease in both cohorts (SEER HR 0·61 [95% CI 0·39-0·94], p=0·024; China HR 0·59 [0·37-0·95]; p=0·029). Furthermore, the protective effect of surgery was observed among patients with locally advanced disease after propensity score matching in the SEER cohort (HR 0·52 [95% CI 0·32-0·84]; p=0·0077). In the China registry, surgery was associated with better outcomes in patients with stage IB3-IIA2 cancer (HR 0·17 [95% CI 0·05-0·50]; p=0·0015). INTERPRETATION: This study provides evidence that surgery improves outcomes of patients with small cell carcinoma of the cervix. Although guidelines recommend non-surgical methods as first-line treatment, patients with locally advanced disease or stage IB3-IIA2 cancer might benefit from surgery. FUNDING: The National Key R&D Program of China and the National Natural Science Foundation of China.

Primary Ovarian Small Cell Carcinoma of Pulmonary Type: Analysis of 6 Cases and Review of 31 Cases in the Literatures.

Objective Primary ovarian small cell carcinoma of pulmonary type (SCCOPT) is a rare ovarian tumor with a poor prognosis. The platinum-based chemotherapy is the standard treatment. However, there is little research on the clinical characteristics of SCCOPT and the potential benefits of other treatments due to its low incidence. The study aims to investigate clinicopathological characteristics and treatment of SCCOPT.Methods We summarized the clinical, imaging, laboratorical and pathological characteristics of 37 SCCOPT cases, in which 6 cases were admitted to the Gansu Provincial Hospital from the year of 2008 to 2022 and 31 cases reported in 17 English and 3 Chinese literatures.Results The median age of the studied SCCOPT cases (n=37) was 56.00 (range, 22-80) years. Almost 80% of them had a stage Ⅲ or Ⅳ tumor. All patients underwent an operation and postoperative chemotherapy. Nevertheless, all cases had a poor prognosis, with a median overall survival time of 12 months. Immunohistochemically, the SCCOPT of all patients showed positive expressions of epithelial markers, such as CD56 and sex-determining region of Y chromosome-related high-mobility-group box 2 (SOX-2), and negative expressions of estrogen receptor, progesterone receptor, vimentin, Leu-7, and somatostatin receptor 2. The tumor of above 80% cases expressed synaptophysin. Only a few cases expressed neuron-specific enolase, chromogranin A, and thyroid transcription factor-1. Conclusions SCCOPT had a poor prognosis. SOX-2 could be a biomarker to be used to diagnose SCCOPT.

Small Cell Carcinoma of the Rectum-An Unexpected Diagnosis: Current Treatment Options for a Rare and Aggressive Entity.

Rectal small cell carcinoma is a rare and aggressive cancer subtype for which a consensus of optimal treatment has not yet been reached. This cancer presents a difficult surgical problem, and thus, the mainstay of treatment tends to mirror that of small cell carcinoma of the lung (chemotherapy, radiation therapy, and immune modulators). This brief report highlights current treatment options available for this rare and difficult entity. There is a significant need for large-center clinical trials and prospective studies to help determine the best treatment regimen to effectively care for patients with small cell carcinoma of the rectum.

[Clinical analysis of 11 patients with neuroendocrine carcinoma in maxillofacial region].

Objective: To investigate the clinicopathological features, treatment and prognosis of maxillofacial neuroendocrine carcinoma. Methods: A total of 11 patients with maxillofacial neuroendocrine carcinoma diagnosed in the Department of Pathology of The First Affiliated Hospital of Zhengzhou University from December 2010 to July 2022 were retrospectively enrolled, including 8 males and 3 females, aged (65.2±9.5) years (ranged from 49 to 87 years), with a disease course of 0.5 to 6.0 months. The clinicopathological data including head and neck CT, MRI and treatment methods were analyzed. Results: Submandibular gland and maxilla were involved in 3 cases, parapharynx in 2 cases, and face, tongue root and soft palate in 1 case respectively. Clinically, the initial symptom is a rapidly growing painless or tender mass, which may be accompanied by restricted mouth opening, dysphagia, and local numbness after invasion of masticatory muscles and nerves. The tumors were all invasive and low-density, with unclear boundaries from the surrounding tissues. Among the patients, 9 received surgical treatment, and 5 received adjuvant treatment after surgery (2 received chemotherapy, 3 received radiotherapy+chemotherapy). According to the 5th edition of the World Health Organization classification of head and neck tumors in 2022, there were 1 case (1/11) with poorly differentiated large cells and 10 cases (10/11) with poorly differentiated small cells. Histologically, the macrocell type is composed of large cells with rough chromatin, obvious vacuolar nucleolus, protruding nucleolus, and necrosis. The small cell type is dominated by small blue round cells with neuroendocrine characteristics, with active growth and multifocal necrosis. Immunohistochemical staining showed that cytokeratin (CK), epithelial membrane antigen (EMA) and synaptophysin (Syn) were diffusively expressed, 10 cases expressed CD56, 8 cases expressed p63, 6 cases expressed weakly punctated chromograin-A (CgA), and S-100 was not expressed. The Ki-67 index ranges from 20 to 90 percent. By the end of follow-up (0.5 to 127.0 months), 3 patients were alive, and the mean progression-free survival (21.0 months) of postoperative chemoradiotherapy patients was significantly longer than that of surgery and/or chemotherapy alone (3.3 months). Conclusions: Maxillofacial neuroendocrine carcinoma is characterized by low differentiation of small cells, high degree of malignancy and poor prognosis. Radical surgery combined with chemoradiotherapy has better local control effect.

Comparison of clinicopathological characteristics, gene expression profiles, mutational analysis, and clinical outcomes of pure and mixed small-cell carcinoma of the bladder.

AIMS: Small cell bladder carcinoma (SCBC) is a rare, divergent form of urothelial carcinoma (UC). We aimed to determine whether pure (n = 16) and mixed (SCBC and UC; n = 30) tumours differed in pathology, gene expression characteristics, genetic alterations, and clinical outcomes. METHODS AND RESULTS: Forty (87%) patients received first-line chemotherapy. Twenty-nine patients had no metastatic disease at diagnosis and underwent radical cystectomy. There were no differences in age, sex, race distribution, tumour size, stage at presentation, therapy response with pathological downstaging to ≤ypT1N0, or overall or progression-free survival (PFS) between pure and mixed tumours. There was a longer PFS among downstaged chemotherapy-responding tumours ≤ypT2N0M0 than among unresponsive tumours ≥ypT2 ≥ yN1M1 (P = 0.001). Patients who achieved pathological downstaging with neoadjuvant chemotherapy (n = 10) were stage cT2N0M0 at the time of diagnosis and were alive at the last follow-up (median 37 months), while 46% of patients who failed to achieve pathological downstaging were alive at the last follow-up (median 38 months; P = 0.008). RNA sequencing showed that the UC of mixed SCBC had similar neural expression signatures to pure SCBC. DNA sequencing revealed alterations in TERT (83%), P53 (56%), ARID1A (28%), RB1 (22%), and BRCA2 (11%). Immunohistochemistry for RB1 showed loss of expression in 18/19 (95%) patients, suggesting frequent pathway downregulation despite a low prevalence of RB1 mutation. CONCLUSION: Patients with pure and mixed SCBC have similar outcomes and these outcomes are determined by the pathological stage at RC and are best among patients who have pathological downstaging after NAC.

Impact of adjuvant chemotherapy on the overall survival of patients with resectable bulky small cell neuroendocrine cervical cancer: a JSGO-JSOG joint study.

OBJECTIVE: The aim of this study was to review the clinicopathological characteristics of small cell neuroendocrine cervical cancer (SCNEC) and to identify the optimal treatment. METHODS: The Japanese Society of Gynecologic Oncology conducted a retrospective cohort study of SCNECs enrolled in the Gynecological Tumor Registry of the Japan Society of Obstetrics and Gynecology between 2004 and 2015. All cases were modified and unified by International Federation of Gynecology and Obstetrics 2008 (Union for International Cancer Control 7th edition). RESULTS: There were 822 registered patients diagnosed with SCNEC from 2004 to 2015 which comprised 1.1% (822/73,698) of all uterine cervical cancer cases. Rates of lymph-node and distant metastasis were significantly higher in T1b2 (38.9% and 13.7%, respectively) than T1b1 (14.2% and 4.4%, respectively) (p<0.01). In IB2 and T1bN1M0 SCNEC, the 5-year survival rate with surgery followed by chemotherapy was significantly higher than that with surgery followed by radiation therapy/concurrent chemoradiation therapy (p<0.01). CONCLUSION: SNCEC tumors >4 cm in size had greater rates of lymph-node and distant metastasis when compared with tumors ≤4 cm. Adjuvant chemotherapy, rather than radiotherapy, may improve prognosis after surgery in T1bN1M0 SCNEC.

Outcomes of extensive stage extrapulmonary small cell cancer.

BACKGROUND: Extrapulmonary small cell cancer (EPSCC) is a rare malignancy with an incidence of approximately 0.1%-0.4% of all cancers. Treatment of this disease is often based on small cell lung cancer. AIMS: We aimed to investigate real-world clinical outcomes of patients with extensive-stage (ES) ESPCC. METHODS: Patients diagnosed with ES EPSCC between 2010 and 2020 from multiple centres in New South Wales were identified. Patient, disease and treatment characteristics were collected and presented using descriptive statistics. Survival was analysed using the Kaplan-Meier method. Univariate and multivariate Cox regression hazard models were used to identify potential prognostic factors. RESULTS: Sixty eligible ES EPSCC patients were identified, including 65% male and 35% female. The mean age was 69 years (range 37-88). Forty-five per cent were never smokers, 42% ex-smokers and 13% current smokers, and 17% of patients had limited-stage disease prior to development of ES disease. The most common primary sites were genitourinary (42%; mainly prostate (n = 14) and bladder (n = 10)), gastrointestinal (28%; mainly oesophagus (n = 5) and colon (n = 4)) and unknown primary (22%). Treatments received included palliative chemotherapy (67%), palliative radiotherapy (53%), palliative surgery (13%) and best supportive care alone (13%). The median overall survival (OS) was 8.0 months. The median progression-free survival was 5.4 months, and response rate to first-line chemotherapy was 65%. Platinum-based chemotherapy was prognostic of longer OS (HR 0.27, CI 0.12-0.60, P = 0.001). CONCLUSIONS: Patients with ES EPSCC had good response to palliative chemotherapy, but OS remained poor. Further research is required to improve the prognosis in this population.

Clinical analysis of 11 patients with neuroendocrine carcinoma in maxillofacial region / 中华口腔医学杂志

Objective: To investigate the clinicopathological features, treatment and prognosis of maxillofacial neuroendocrine carcinoma. Methods: A total of 11 patients with maxillofacial neuroendocrine carcinoma diagnosed in the Department of Pathology of The First Affiliated Hospital of Zhengzhou University from December 2010 to July 2022 were retrospectively enrolled, including 8 males and 3 females, aged (65.2±9.5) years (ranged from 49 to 87 years), with a disease course of 0.5 to 6.0 months. The clinicopathological data including head and neck CT, MRI and treatment methods were analyzed. Results: Submandibular gland and maxilla were involved in 3 cases, parapharynx in 2 cases, and face, tongue root and soft palate in 1 case respectively. Clinically, the initial symptom is a rapidly growing painless or tender mass, which may be accompanied by restricted mouth opening, dysphagia, and local numbness after invasion of masticatory muscles and nerves. The tumors were all invasive and low-density, with unclear boundaries from the surrounding tissues. Among the patients, 9 received surgical treatment, and 5 received adjuvant treatment after surgery (2 received chemotherapy, 3 received radiotherapy+chemotherapy). According to the 5th edition of the World Health Organization classification of head and neck tumors in 2022, there were 1 case (1/11) with poorly differentiated large cells and 10 cases (10/11) with poorly differentiated small cells. Histologically, the macrocell type is composed of large cells with rough chromatin, obvious vacuolar nucleolus, protruding nucleolus, and necrosis. The small cell type is dominated by small blue round cells with neuroendocrine characteristics, with active growth and multifocal necrosis. Immunohistochemical staining showed that cytokeratin (CK), epithelial membrane antigen (EMA) and synaptophysin (Syn) were diffusively expressed, 10 cases expressed CD56, 8 cases expressed p63, 6 cases expressed weakly punctated chromograin-A (CgA), and S-100 was not expressed. The Ki-67 index ranges from 20 to 90 percent. By the end of follow-up (0.5 to 127.0 months), 3 patients were alive, and the mean progression-free survival (21.0 months) of postoperative chemoradiotherapy patients was significantly longer than that of surgery and/or chemotherapy alone (3.3 months). Conclusions: Maxillofacial neuroendocrine carcinoma is characterized by low differentiation of small cells, high degree of malignancy and poor prognosis. Radical surgery combined with chemoradiotherapy has better local control effect.