ReviewMechanismInconclusiveModerate evidenceTier 4 · clinical
Histopathology · Jan 2026
neuroendocrine tumour of the urinary bladdersmall cell carcinomalarge cell neuroendocrine carcinomawell-differentiated neuroendocrine tumourparaganglioma
This review summarizes recent advances in the pathology and molecular understanding of neuroendocrine tumours of the urinary bladder. It reports that small cell carcinoma is the most commonly encountered bladder NET and may occur alone or alongside urothelial carcinoma or other histologies. Large-cell neuroendocrine carcinoma is being increasingly recognized but remains incompletely characterized, whereas well-differentiated NETs and paragangliomas of the bladder are rare. The authors state that molecular characterization advances have improved biological understanding and may enable better classification and risk stratification.
Studied with: urothelial carcinoma, other histological subtypes.
Key findings
- Small cell carcinoma is the most frequently encountered neuroendocrine tumour of the urinary bladder and may present as either pure or in combination with urothelial carcinoma or other histological subtypes.
- Large cell neuroendocrine carcinoma is increasingly recognized in this location, but it is not yet fully characterized.
- Well-differentiated NET and paraganglioma of the bladder are rare neuroendocrine neoplasms.
- Advances in the molecular characterization of these tumours have enhanced our understanding of their biology and can provide better classification and more accurate risk stratification for clinical decision-making.
Limitations: Narrative review format (no methods, search strategy, or systematic synthesis described in the abstract).; Abstract does not present new primary data or quantitative results.; Abstract provides no details on specific molecular markers, study cohorts, or clinical outcome data..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed
ReviewInconclusiveLimited evidenceTier 4 · clinical
Bladder cancer (Amsterdam, Netherlands) · Aug 2025 · narrative review
small cell carcinoma of the bladder (SCCB)
This is a narrative review of small cell carcinoma of the bladder (SCCB), a rare and aggressive subtype that represents under 1% of bladder cancers. The authors summarize clinical presentation, staging, local and systemic management, and molecular insights, noting most treatment regimens are extrapolated from small cell lung cancer and that novel agents are in development. They call for greater preclinical research and increased patient participation in clinical trials.
Key findings
- SCCB is a rare, aggressive malignancy accounting for less than 1% of bladder cancers.
- The review summarizes epidemiology, cystoscopic and imaging findings, staging methods, local and systemic treatment approaches, and molecular mechanisms underlying SCCB.
- Most treatment regimens for SCCB are extrapolated from small cell lung cancer due to shared neuroendocrine features and aggressive phenotype.
- Novel agents for SCCB are in clinical development.
- The authors recommend increased preclinical research and greater participation of SCCB patients in clinical trials to expand treatment options.
Limitations: Review article with no new primary data reported.; Evidence base is limited and heterogeneous because SCCB is rare (<1% of bladder cancers).; Many treatment recommendations are extrapolated from small cell lung cancer rather than SCCB-specific trials.; Likely lack of large, randomized clinical trials specific to SCCB..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Case reportMixed resultsLimited evidenceTier 3 · early humann = 1
Radiology case reports · Mar 2025 · case report
This is a single-patient case report of extrapulmonary small cell carcinoma of the liver in a 52-year-old woman. The patient received systemic chemotherapy with carboplatin and etoposide combined with durvalumab, had clinical improvement of symptoms, but died 10 months after starting chemoimmunotherapy. The authors note that optimal treatment for EPSCC is generally extrapolated from small cell lung cancer and that there is insufficient evidence to routinely recommend immunotherapy in this group.
Reported effects: tumor_dimensions, n=1 · time_to_death_after_starting_chemoimmunotherapy 10 mo, n=1
Studied with: carboplatin, etoposide, carboplatin + etoposide.
Key findings
- Diagnosis of EPSCC of the liver was made after biopsy and immunohistochemistry (positive for CKA1/A3, chromogranin, synaptophysin, CD56 and TTF-1).
- Abdominal MRI showed an enlarged liver secondary to a mass affecting segments IV, V, VI, VII and VIII of 16.9 × 9.4 cm.
- Systemic chemotherapy with carboplatin and etoposide plus durvalumab was started.
- There was clinical improvement of the symptoms after starting treatment.
- The patient died 10 months after starting chemoimmunotherapy treatment.
- Authors state that optimal treatment of EPSCC is generally extrapolated from small cell lung cancer and there is insufficient evidence to routinely recommend immunotherapy for EPSCC.
Limitations: Single-patient case report (n=1), so findings are not generalizable.; No control or comparator group to assess treatment effect.; No dosing, schedule, or detailed treatment toxicity information provided.; Cannot establish causality or efficacy from a single observational case.; EPSCC is rare and treatment recommendations are extrapolated from small cell lung cancer, limiting direct applicability..
This report describes use of carboplatin + etoposide chemotherapy combined with durvalumab in a patient with extrapulmonary small cell carcinoma of the liver.
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Human · observationalReported positiveLimited evidenceTier 3 · early humann = 3
Human vaccines & immunotherapeutics · Dec 2024 · case series (3 patients)
small cell carcinoma of the esophagus (SCCE)
This case series reports three patients with small cell carcinoma of the esophagus treated with chemoimmunotherapy. Two limited-stage patients received neoadjuvant chemoimmunotherapy followed by surgery and experienced notable, durable positive responses. The authors performed immunohistochemistry and whole exome sequencing and found that tumor CD8+ T-cell infiltration and PD-L1 expression were associated with favorable responses. This is described as the first reported use of neoadjuvant chemoimmunotherapy in limited-stage SCCE.
Studied with: chemotherapy, immunotherapy.
Key findings
- Three SCCE patients (one extensive-stage, two limited-stage) were treated with chemoimmunotherapy.
- The two limited-stage patients underwent surgery after neoadjuvant chemoimmunotherapy and experienced notable and enduring positive responses.
- Comprehensive immunohistochemical analysis and whole exome sequencing indicated that infiltration of CD8+ T cells and PD-L1 expression in the tumor were key factors associated with favorable responses to chemoimmunotherapy.
Limitations: Very small sample size (three patients) from a case series; No control or comparison group; Treatment regimen details (drug names, doses, schedules) are not reported in the abstract; Follow-up duration and objective outcome measures are not described in the abstract; Observational case reports cannot establish causality; biomarker associations are exploratory.
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Case reportInconclusiveLimited evidenceTier 3 · early humann = 1
ACG case reports journal · Oct 2024 · case report
gastric small cell carcinomaGSCCsmall cell carcinoma of the stomach
This is a single-patient case report describing a 57-year-old man who presented with partial gastrointestinal obstruction and was found to have primary stage IV gastric small cell carcinoma with liver metastases. The authors note GSCC is a rare, aggressive neuroendocrine tumor with early widespread metastasis and historically poor overall survival (<12 months), and that treatment regimens often mirror those used for small cell lung carcinoma because of histopathologic similarity.
Key findings
- Primary gastric small cell carcinoma (GSCC) is an extremely rare type of small cell carcinoma.
- GSCC has an aggressive nature with early widespread metastasis and late detection, giving it a poor prognosis with overall survival of <12 months.
- GSCC is a type of neuroendocrine tumor and, because of histopathological similarity to small cell lung carcinoma (SCLC), treatment regimens of GSCC include the same chemotherapy agents as SCLC.
- Case reported: a 57-year-old man presented with signs of partial gastrointestinal obstruction and was found to have a primary stage IV GSCC with metastasis to the liver.
Limitations: Single-patient case report — findings are not generalizable.; No experimental intervention or comparative data reported.; No quantitative outcomes or follow-up data provided for this patient.; Prognostic statistic (<12 months overall survival) is presented as background rather than as a result from this case..
Clinical case description of a rare, aggressive gastric small cell carcinoma with metastatic disease.
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
ReviewMechanismInconclusiveLimited evidenceTier 4 · clinical
Frontiers in immunology · Aug 2024 · review
neuroendocrine neoplasms of the thymustypical carcinoidatypical carcinoidlarge cell neuroendocrine carcinomasmall cell carcinomathymus neoplasms
This is a narrative review summarizing neuroendocrine neoplasms of the thymus (tNENs), including typical and atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma. The authors note these tumors are rare, that clinical and pathological data are scarce, and that tNENs share features with neuroendocrine neoplasms in other organs (notably the lung) while also having some distinct clinical and pathological characteristics; the review focuses on pathologic diagnosis and differential diagnosis.
Key findings
- tNENs include typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma.
- These tumors are rare and there are scarce clinical and pathological data available in the literature.
- tNENs share many common features with neuroendocrine neoplasms in other organs (such as the lung) but also demonstrate some distinct clinical and pathological features.
- The review primarily focuses on pathologic diagnosis and differential diagnosis of tNENs.
Limitations: Narrative review rather than original research; no new primary data are reported.; Abstract states clinical and pathological data on tNENs are scarce, limiting conclusions.; No quantitative results, methods, or systematic review/meta-analysis methodology are provided in the abstract..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Animal studyReported positivePreclinical onlyTier 2 · animal
Signal transduction and targeted therapy · Jul 2024
lung adenocarcinomaprostate adenocarcinomasmall cell carcinoma (lung and prostate)neuroendocrine transformation
The study tested CDC7 inhibition with simurosertib in models of neuroendocrine (NE) transformation in lung and prostate tumors. In in vivo models, CDC7 inhibition suppressed NE transdifferentiation and extended responses to targeted therapy and to cytotoxic drugs by inducing proteasome-mediated degradation of the MYC oncoprotein; a degradation-resistant MYC isoform reversed this effect.
Studied with: targeted therapy (unspecified), cisplatin, irinotecan.
Key findings
- CDC7 is upregulated during the initial steps of neuroendocrine transformation after TP53/RB1 co-inactivation.
- CDC7 inhibition with simurosertib suppressed NE transdifferentiation and extended response to targeted therapy in in vivo models of NE transformation.
- CDC7 inhibition induced proteasome-mediated degradation of MYC, implicated in stemness and histological transformation.
- Ectopic overexpression of a degradation-resistant MYC isoform reestablished the NE transformation phenotype even in the presence of simurosertib.
- CDC7 inhibition markedly extended response to standard cytotoxics (cisplatin, irinotecan) in lung and prostate small cell carcinoma models.
- Authors propose CDC7 inhibition as a strategy to constrain lineage plasticity and to treat NE tumors; simurosertib clinical trials are ongoing (not reported in this study).
Limitations: All reported experiments are preclinical (in vivo models); no human trial data are presented in this abstract.; The abstract does not report sample sizes, doses, or detailed experimental parameters.; Species and detailed model descriptions are not specified in the abstract.; Safety, toxicity, and clinical efficacy in patients are not addressed in this study..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text
Case reportInconclusiveLimited evidenceTier 3 · early humann = 1
Caspian journal of internal medicine · Jul 2024 · case report
small cell carcinoma of the uterine cervixcervical cancer
This is a case report of a 47-year-old woman with a history of breast cancer who presented with abnormal vaginal bleeding and was diagnosed with small cell carcinoma of the cervix. She underwent radical hysterectomy with bilateral salpingo-oophorectomy and then received postoperative adjuvant chemoradiation. The authors state that small cell carcinoma of the cervix is aggressive with poor prognosis and that optimal treatment remains unsettled.
Key findings
- Patient: 47-year-old woman with prior breast cancer presented with abnormal vaginal bleeding and was diagnosed with small cell carcinoma of the cervix.
- Treatment reported: radical hysterectomy and bilateral salpingo-oophorectomy followed by adjuvant chemoradiation.
- Authors' conclusion: small cell carcinoma of the cervix is aggressive and has poor prognosis; optimal treatment remains unsettled.
Limitations: Single-patient case report (n=1), so findings are not generalizable.; Abstract does not report clinical outcome, follow-up duration, or treatment response.; No control group or comparative data.; Limited clinical and pathological detail provided in the abstract..
AI summary of the abstract, human-reviewed · Jun 2026. Describes what this study reported, not medical advice. View on PubMed · Full text