BACKGROUND: Both small-cell carcinoma (SCLC) and large-cell neuroendocrine carcinoma (LCNEC) of the lung are often clinically dealt with as being in the same category as neuroendocrine carcinoma, and their clinical differences have not been adequately assessed.
METHODS: The postoperative prognosis was retrospectively analyzed using the data of 196 patients who underwent resection for SCLC or LCNEC.
RESULTS: Of the patients included, 99 (50.5%) had SCLC and 97 (49.5%) had LCNEC. The median duration of follow-up was 39 months (interquartile range [IQR] 21-76) and 56 months (IQR 21-87) for SCLC and LCNEC, respectively. The estimated 5-year overall survival (OS) probabilities were 53.7% and 62.7% (p = 0.133) for patients with SCLC and LCNEC, respectively. In the SCLC group, a multivariate analysis showed that adjuvant chemotherapy (hazard ratio 0.54, 95% confidence interval 0.30-0.99, p = 0.04) was the only factor that was significantly associated with OS. In the LCNEC group, univariate analyses demonstrated that pathologic stage I (p = 0.01) was the only factor that was associated with better OS after surgery.
CONCLUSIONS: We found different clinical features in SCLC and LCNEC; in patients with SCLC, because OS could be expected to significantly improve with postoperative adjuvant chemotherapy, patients with resected SCLC of any pathologic stage should receive adjuvant chemotherapy. For patients with LCNEC, because pathologic stage I LCNEC is related to better prognosis than any other stages, a thorough clinical staging, including invasive staging, according to present guidelines should be performed to identify clinical stage I LCNEC with the highest certainty.

Large cell neuroendocrine carcinoma (LCNEC) is an extremely rare malignant tumor of the colon, presenting with more severe clinical outcomes in comparison to colonic adenocarcinoma. There are very few reported cases in the literature. We hereby add our voice to the incidence of this disease by presenting the first report of a patient with ileocolic intussusception secondary to a large cell neuroendocrine cancer of the cecum. The patient was a 48-year-old woman who presented with acute onset of generalized abdominal pain and leukocytosis. CT scan revealed an ileocecal intussusception and multiple liver metastases suggestive of a malignant bowel lesion. She underwent emergency surgery, and an extended right hemicolectomy with ileo-transverse anastomosis was performed. Histology of the resected lesion revealed large cell neuroendocrine carcinoma of the cecum with invasion through the muscularis propria into peri colorectal tissues. The tumor retained mismatch repair (MMR) proteins with low potential for microsatellite instability (MSI). With a clinical diagnosis of stage IV LCNEC, the patient began platinum doublet chemotherapy with carboplatin and etoposide; however, her disease progressed, and the patient expired within a few months after her diagnosis. Clinical diagnosis of adult intussusception should prompt clinicians to rule out malignant etiology. This patient had a large cell neuroendocrine carcinoma of the colon, a rare and extremely aggressive malignancy. Patients with LCNEC will benefit from a multidisciplinary approach to treatment.

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disorder characterized by myoclonus, ataxia, and tremors. It can be classified as neoplastic or idiopathic, with small cell lung cancer being commonly associated. Herein, we present a rare case of refractory paraneoplastic neurological syndrome (PNS) caused by large cell neuroendocrine carcinoma (LCNEC), a rare form of non-small cell lung cancer (NSCLC). A 60-year-old otherwise healthy man presented with acute-onset dysarthria, gait instability, and numbness on the right side of his body. According to the clinical symptoms and neurological examination, we initially suspected cerebellar infarction; however, brain imaging revealed no abnormal findings. After a few days, the patient developed worsening horizontal nystagmus, irregular ocular rhythms, and generalized involuntary movements, indicative of OMS. A systemic evaluation revealed a solitary nodule in the lower lobe of the right lung, leading to a clinical diagnosis of PNS. The patient underwent segmentectomy to treat an early-stage LCNEC nodule after one month from onset. Despite all therapeutic interventions, OMS was refractory, and after consulting with the person himself and the family, palliative care was selected. However, the patient showed a clinical response belatedly five months after surgery. This case highlights the importance of considering PNS, and that it may be associated with a rare malignancy when cerebellar symptoms are observed, and the challenges in managing refractory PNS associated with rare forms of NSCLC.

OBJECTIVE: Cytoplasmic p53 expression indicates a high frequency of TP53 abnormalities in gynaecological carcinoma. However, the implication of this expression in pulmonary neuroendocrine carcinoma (NEC) remains unclear. Thus, our study aimed to fill this research gap.
RESULTS: Immunohistochemistry (IHC) of p53 was performed on 146 cases of resected small-cell lung carcinoma and large-cell NEC, and next-generation sequencing was conducted on cases showing cytoplasmic and wild-type p53 expression. IHC revealed overexpression in 57% of the cases (n = 83), complete absence in 31% (n = 45), cytoplasmic expression in 8% (n = 12) and wild-type expression in 4% (n = 6) of the cases. TP53 mutations were identified in nine of the 13 cases with available genetic analysis. The TP53 mutation rates in cases with cytoplasmic and wild-type p53 expression were 88% (seven of eight) and 40% (two of five), respectively. All seven cases showing cytoplasmic expression with TP53 mutations harboured loss-of-function type mutations: four had mutations in the DNA-binding domain, two in the nuclear localisation domain and one in the tetramerisation domain. Clinically, cases with cytoplasmic p53 expression had a poor prognosis similar to that in cases with p53 overexpression or complete absence.
CONCLUSIONS: Cytoplasmic p53 expression in patients with pulmonary NEC suggests a high TP53 mutation rate, which is associated with a poor prognosis similar to that in patients with p53 overexpression or complete absence. This cytoplasmic expression should not be misidentified as a wild-type expression. This is the first report, to our knowledge, that demonstrates the implication of cytoplasmic p53 expression in pulmonary NEC.

BACKGROUND: According to the 2019 World Health Organization (WHO) classification of gastric neuroendocrine neoplasms, gastric neuroendocrine carcinoma (GNEC) can be further divided into gastric large-cell neuroendocrine carcinoma (GLNEC) and gastric small-cell neuroendocrine carcinoma (GSNEC). Whether the prognoses of the two types have a discrepancy has long been disputed.
METHODS: We collected patients diagnosed with GLNEC or GSNEC in the National Cancer Center of China between January 2000 and December 2020. The characteristics and survival outcomes were compared between the two groups. We further verified our conclusion using the SEER dataset.
RESULTS: A total of 114 GNEC patients, including 82 patients with GLNEC and 32 patients with GSNEC, have completed treatment in our hospital. Clinicopathologic differences were not observed between patients with GSNEC and GLNEC concerning the sex, age, body mass index, Charlson Comorbidity Index, tumor location, tumor size, stage, treatment received, the expression of neuroendocrine markers (CD56, Chromogranin A, synaptophysin), and score on the Ki-67 index. The 1-year, 3-year, and 5-year overall survival rates of GLNEC and GSNEC were 89.0%, 60.5%, and 52.4%, and 93.8%, 56.3%, and 52.7%, which showed no statistically significant differences. This result was confirmed further by using the SEER dataset after the inverse probability of treatment weighting.
CONCLUSIONS: Although with different cell morphology, the comparison of prognosis between the GLNEC and GSNEC has no significant statistical difference.

BACKGROUND: With the widespread use of low-dose computed tomography for lung cancer screening, the detection rate of pulmonary lesions manifesting as ground-glass opacities (GGOs) has been increasing dramatically. The volume doubling time (VDT) has been introduced in clinical practice to monitor the potential growth rate of GGOs during long-term follow-up periods.
METHODS: A 72-year-old never-smoker female diagnosed with mixed GGO manifested abruptly accelerated growth with sudden decreased VDT from 400 to 36 days. A thoracoscopic left lower lobectomy with mediastinal lymph node dissection was performed, and the diagnosis was stage IB large-cell neuroendocrine carcinoma (LCNEC). Next-generation sequencing of the tumor highlights an EML4-ALK gene fusion.
CONCLUSIONS: The LCNEC may present as GGO with longer VDT in the early stage. VDT should calculate by the whole size either on the entire tumor diameter or on consolidation diameter. It is recommended that meticulous long-term follow-up with dynamic VDT monitoring may help select high-risk GGOs performing timely semi-elective surgical resection in clinical practice.

OBJECTIVE: This study aimed to investigate the prognostic significance of surgery in large-cell neuroendocrine carcinoma (LCNC) patients.
METHODS: A total of 453 patients from the Surveillance, Epidemiology, and End Results database diagnosed with stage T1-4N0-2M0 LCNC from 2010 to 2015 were analyzed. The propensity-score matching analysis with a ratio of 1:1 was used to minimize the bias effect of other clinical characteristics, and 77 pairs of patients\' data were performed for subsequent statistical analysis. The Cox proportional hazards model, Kaplan-Meier analysis, and Log-rank test were used in the present study. The primary observational endpoint was cancer-specific survival (CSS).
RESULTS: The 1-year, 3-year, and 5-year CSS rates were 60.0%, 45.0%, and 42.0% in those 453 LCNC patients. Compared with patients who underwent surgical resection, patients without surgery had a lower 5-year CSS rate (18.0% vs. 52.0%, P < 0.001). After analyses of multivariable Cox regression, chemotherapy, T stage, N stage, and surgery were identified as independent prognostic indicators (all P < 0.05). In the cohort of old patients, the median survival time was longer in cases after surgery than those without surgery (13.0 months vs. NA, P < 0.001). Besides, in patients with different clinical characteristics, the receiving surgery was a protective prognostic factor (all hazard ratio < 1, all P < 0.05). In addition, for the cohort with stage T1-2N0-2M0, patients after the operation had more improved outcomes than patients without surgery (P < 0.001).
CONCLUSIONS: We proposed that the surgery could improve the survival outcomes of LCNC patients with stage T1-4N0-2M0. Moreover, old patients could benefit from surgery.

Gallbladder neuroendocrine carcinoma is rare, representing ~4% of all primary malignant gallbladder neoplasms. We report the case of a 75-year-old female who presented for radiologic restaging for lung adenocarcinoma diagnosed elsewhere, demonstrating a hypermetabolic gallbladder mass. With concern for a gallbladder primary, radical cholecystectomy followed. Gross showed a 2-cm polypoid fundic mass; microscopically, tumor cells were arranged in sheets, with organoid features and necrosis, variable cytoplasm, vesicular-granular chromatin, prominent nucleoli, frequent mitoses, and apoptotic figures. Immunohistochemically, synaptophysin, chromogranin, CK7, and TTF-1 were positive; Ki67 was 80%. The combined findings were diagnostic of large-cell neuroendocrine carcinoma. Further investigation including outside slide review with additional stains revealed the lung primary to be classified large-cell neuroendocrine carcinoma, thus the gallbladder tumor representing metastasis. Within 4 months, the patient expired with widespread metastases. To our knowledge, this is the first reported case of metastatic lung large-cell neuroendocrine carcinoma to gallbladder in the English literature.

Thymic neuroendocrine tumors associated with multiple endocrine neoplasia are only defined as carcinoid and are not associated with large-cell neuroendocrine carcinoma (LCNEC). We report the case of a multiple endocrine neoplasia type 1 patient with atypical carcinoid tumors with elevated mitotic counts (AC-h), an intermediate condition between carcinoid and LCNEC. A 27-year-old man underwent surgery for an anterior mediastinal mass and was diagnosed with thymic LCNEC. Fifteen years later, a mass appeared at the same site, which was determined to be a postoperative recurrence based on the pathological results of a needle biopsy and the clinical course. The patient\'s disease remained stable for 10 months on anti-programmed death-ligand 1 antibody and platinum-containing chemotherapy. The needle biopsy specimen was submitted for next-generation sequencing, which revealed a MEN1 gene mutation, and after further examination, a diagnosis of multiple endocrine neoplasia type 1 was made. A re-examination of the surgical specimen from 15 years prior showed that it corresponded to AC-h. Although thymic AC-h is classified as thymic LCNEC according to the current definition, our data suggests that a search for multiple endocrine neoplasia is warranted in such patients.

Primary lung cancers in children are rare, and most children are diagnosed incidentally while being investigated for another medical problem. The diagnosis of primary lung tumors in children is very difficult because many children are asymptomatic until the advanced stages of the disease and nonspecific imaging findings. Although the usage of 68Ga-tetraazacyclododecane tetraacetic acid-DPhe1-Tyr3-octreotate (68Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT) in adult patients is well known, it is a relatively new imaging modality for the pediatric patient group. Herein, we presented a unique case of large-cell neuroendocrine carcinoma of the lung in a child on 68Ga-DOTATATE PET/CT.