Small cell carcinoma of the urinary bladder: a rare, aggressive neuroendocrine malignancy

Effect of chemotherapy alone or combined with immunotherapy for locally advanced or metastatic genitourinary small cell carcinoma: a real-world retrospective study

BACKGROUND

Genitourinary small cell carcinoma is rare, and has a poor prognosis. However, effective treatment options for this disease are limited. We present a study to assess the efficacy of chemotherapy alone or combined with immunotherapy for locally advanced or metastatic genitourinary small cell carcinoma (GSCC).

METHODS

We performed a retrospective analysis of patients with locally advanced or metastatic GSCC from Jan 2013 to September 2022 at Sun Yat-sen University Cancer Center. The survival and safety profiles were analyzed.

RESULTS

Forty-two GSCC patients were enrolled, which included 20 with chemotherapy plus immunotherapy and 22 with chemotherapy alone. The median follow-up time was 15.13 months (95% CI, 8.84-21.42). The addition of immunotherapy to chemotherapy demonstrated no significant difference in median progression-free survival (p = 0.37). However, the median overall survival (OS) was 22.97 and 14.03 months with immunotherapy plus chemotherapy and chemotherapy alone, respectively (HR = 0.69, 95%CI 0.08-0.55, p = 0.017). Two patients with immunotherapy plus chemotherapy achieved clinical complete remission. The overall response rate for patients receiving chemotherapy combined with immunotherapy was 65%, which was higher in comparison to those treated with chemotherapy alone (50%). Univariate and multivariate analyses demonstrated that chemotherapy combined with immunotherapy independently achieved favorable OS. Four patients experienced immunotherapy-related adverse events, with one developing grade 3 hypothyroidism.

CONCLUSIONS

Among patients with locally advanced or metastatic GSCC, immunotherapy combined with chemotherapy might be thought of as a potentially effective treatment option for patients with GSCC.

Small-cell neuroendocrine tumor of the bladder: Unexpected long-term survival with carboplatin-etoposide therapy in a patient with metastatic stage disease

Neuroendocrine small-cell bladder cancer is an extremely rare and aggressive entity, it constitutes <1% of all bladder malignancies. The small-cell neuroendocrine histological variant has a worse prognosis than the classical subtypes. A case of a 53-year-old female consulting with gross hematuria is presented. Cystoscopy revealed a solid aspect lesion involving the posterior wall and dome that was resected. Histopathological findings showed small-cell pure variant carcinoma, high grade, with lymph, vascular, and perineural infiltration, infiltrating the muscle layer. The extension study made by hole body computed tomography scan, showed evidence of multiple lymph nodes and multiple visceral radiological involvements, with pulmonary, hepatic, and peritoneal implants. More than 10 years later, after receiving nine cycles of carboplatin-etoposide remains in complete remission and without radiological evidence of the disease. This is, to our knowledge, one of the longest disease-free survival cases in metastatic small-cell bladder cancer published nowadays.

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.

Long-term complete response in small cell bladder carcinoma treated with carboplatin, etoposide, and atezolizumab

Background

Small cell bladder carcinoma (SCBC) is a rare and aggressive malignant tumor with no established treatment guidelines. Its treatment algorithm has been based on the small cell lung cancer (SCLC) guidelines. Metastatic SCBC has poor prognosis (even when treated with platinum-based chemotherapy, which is usually used for extensive-disease SCLC).

Case presentation

Herein, we report a case of a 71-year-old man with SCBC who underwent radical cystectomy and received adjuvant chemotherapy with gemcitabine and cisplatin. However, recurrent tumors were found 6 months postoperatively. The patient was then treated with carboplatin, etoposide, and atezolizumab and achieved complete response. He continues receiving maintenance therapy with atezolizumab monotherapy without any evidence of recurrence over the 12 months follow up.

Conclusion

To our knowledge, this is the first case of metastatic SCBC where carboplatin, etoposide, and atezolizumab achieved long-term complete response.

Metastatic small-cell carcinoma of the bladder that maintains a complete response to chemoradiation therapy

Introduction

Small-cell carcinoma of the urinary bladder has a poor prognosis, and no standard treatment has been established. We encountered a case of a patient with metastasis in which complete response and long-term survival were obtained by treating the primary lesion with a combination of irinotecan, carboplatin chemotherapy, and radiation therapy.

Case presentation

An 83-year-old man was diagnosed with a bladder tumor with liver metastasis. Small-cell carcinoma was diagnosed via transurethral resection. Second-line chemotherapy with irinotecan and carboplatin and irradiation of the primary lesion were significantly effective. The imaging evaluation showed a complete response. The therapeutic effect was maintained for 1 year, even after the discontinuation of chemotherapy.

Conclusion

Irinotecan and carboplatin should be considered for the treatment of small-cell carcinoma of the bladder. Irradiation of the primary lesion may also be useful if the extent of metastasis is low.

Prognostic Factors of Survival for High-Grade Neuroendocrine Neoplasia of the Bladder: A SEER Database Analysis

Background: High-grade neuroendocrine carcinoma (NEC) is a rare and aggressive variant of bladder cancer. Considering its rarity, its therapeutic management is challenging and not standardized. Methods: We analyzed data extracted from the Surveillance, Epidemiology, and End Results (SEER) registry to evaluate prognostic factors for high-grade NEC of the bladder. Results: We extracted data on 1134 patients: 77.6% were small cell NEC, 14.6% were NEC, 5.5% were mixed neuro-endocrine non-neuroendocrine neoplasia, and 2.3% were large cell NEC. The stage at diagnosis was localized for 45% of patients, lymph nodal disease (N+M0) for 9.2% of patients, and metastatic disease for 26.1% of patients. The median overall survival (OS) was 12 months. Multivariate analysis detected that factors associated with worse OS were age being >72 years old (HR 1.94), lymph nodal involvement (HR 2.01), metastatic disease (HR 2.04), and the size of the primary tumor being >44.5 mm (HR 1.80). In the N0M0 populations, the size of the primary tumor being <44.5 mm, age being <72 years old, and major surgery were independently associated with a lower risk of death. In the N+M0 group, the size of the primary lesion was the only factor to retain an association with OS. Conclusions: Our SEER database analysis evidenced prognostic factors for high-grade NEC of the bladder that are of pivotal relevance to guide treatment and the decision-making process.

Classifying Pulmonary and Urinary High-grade Neuroendocrine Carcinoma by CK7 Immunohistochemistry

High-grade neuroendocrine carcinoma (HGNEC) is subclassified into small cell carcinoma (SmCC) and large cell neuroendocrine carcinoma (LCNEC). Although both are clinically aggressive, the SmCC and LCNEC need to have different treatment strategies, and accurate pathologic diagnosis is challenging. We studied a large retrospective cohort (186 cases) of HGNEC of bladder and lung to investigate the abundance of cytokeratin (CK) 7 expression and staining pattern in SmCC and LCNEC. Overall, the pulmonary and urinary HGNEC exhibited several different CK7 staining patterns, including negative staining (n=28), dot-like staining (n=73), partial membranous staining (n=26), and complete membranous staining (n=60). Overall, 88.9% (44/49) of pulmonary SmCC and 88.0% (44/50) of urinary SmCC showed negative or dot-like patterns for CK7, while 90.8% (59/65) of pulmonary LCNEC and 72.7% (16/22) of urinary LCNEC showed partial or complete membranous patterns for CK7 (χ 2 =105.05, P <0.0001). The distinct staining patterns were also present in those mixed SmCC and LCNEC. In addition, the specimen types or fixation did not affect CK7 staining patterns. In conclusion, CK7 has a high differential value for SmCC and LCNEC and could help guide personalized treatment for patients.

Neuroendocrine Neoplasms of the Female Genitourinary Tract: A Comprehensive Overview

Simple Summary

Primary neuroendocrine neoplasms (NENs) are a rare, heterogeneous group of tumors that include well-differentiated neuroendocrine tumors, poorly differentiated neuroendocrine carcinoma, and paraganglioma. NENs in the urinary tract are observed in <0.05% of individuals, in whom the bladder is the most common site. In this review, we described the epidemiology, pathogenesis, imaging, staging, and management of the genitourinary NENs.

Abstract

Primary neuroendocrine neoplasms are a rare heterogeneous group of tumors that include well-differentiated neuroendocrine tumors, poorly differentiated neuroendocrine carcinoma, and paraganglioma. An extensive literature search was used to compile the data regarding epidemiology, pathogenesis, imaging features, and management of the urinary system NENs. We also included the updated staging of the NENs at various locations of the urinary system.

Synaptophysin, CD117, and GATA3 as a Diagnostic Immunohistochemical Panel for Small Cell Neuroendocrine Carcinoma of the Urinary Tract

Although SCNEC is based on its characteristic histology, immunohistochemistry (IHC) is commonly employed to confirm neuroendocrine differentiation (NED). The challenge here is that SCNEC may yield negative results for traditional neuroendocrine markers. To establish an IHC panel for NED, 17 neuronal, basal, and luminal markers were examined on a tissue microarray construct generated from 47 cases of 34 patients with SCNEC as a discovery cohort. A decision tree algorithm was employed to analyze the extent and intensity of immunoreactivity and to develop a diagnostic model. An external cohort of eight cases and transmission electron microscopy (TEM) were used to validate the model. Among the 17 markers, the decision tree diagnostic model selected 3 markers to classify NED with 98.4% accuracy in classification. The extent of synaptophysin (>5%) was selected as the initial parameter, the extent of CD117 (>20%) as the second, and then the intensity of GATA3 (≤1.5, negative or weak immunoreactivity) as the third for NED. The importance of each variable was 0.758, 0.213, and 0.029, respectively. The model was validated by the TEM and using the external cohort. The decision tree model using synaptophysin, CD117, and GATA3 may help confirm NED of traditional marker-negative SCNEC.

Hemorrhagic brain metastasis from small-cell carcinoma of the urinary bladder

Background:

Small-cell carcinoma of the urinary bladder (SCCB) accounts for 1% of all bladder tumors. We present a rare case of hemorrhagic metastatic brain tumor from SCCB diagnosed by navigation-guided endoscopic biopsy.

Case Description:

A 76-year-old man presented with sudden onset of aphasia and right hemiplegia from 3 weeks previously. He had a medical history of prostate cancer and SCCB. Computed tomography showed a mixed density mass in the left basal ganglia. On magnetic resonance imaging, the mass showed mixed intensity in both T1-weighted images and T2-weighted images, suggesting subacute hemorrhage. The mass was partially enhanced with gadolinium. The patient underwent endoscopic hematoma evacuation and partial removal of the tumor. Histopathological diagnosis was neuroendocrine carcinoma, which was consistent with SCCB metastasis. After surgery, the patient underwent whole-brain radiation therapy of 30 Gy. His general condition gradually deteriorated, however, and he died 4 months after surgery.

Conclusion:

Our patient had a rare case of brain metastasis derived from SCCB which presented with cerebral hemorrhage. Navigation-guided endoscopic biopsy was useful for the diagnostic sampling of deep localized brain tumors with hemorrhage.

Insulinoma-associated Protein 1 (INSM1) Expression in Small Cell Neuroendocrine Carcinoma of the Urinary Tract

Clinical guidelines state that neoadjuvant chemotherapy should be administered before surgery in muscle invasive urinary bladder small cell neuroendocrine carcinoma. Recently described marker insulinoma-associated protein 1 (INSM1) has been reported to be sensitive and specific for neuroendocrine differentiation, however, its efficacy in urinary tract small cell carcinoma is not well established. This study examines immunohistochemical expression of INSM1 on whole tissue sections of urinary tract small cell neuroendocrine carcinoma and compares INSM1 expression with established neuroendocrine markers. Immunohistochemical stains for CD56, INSM1, synaptophysin, and chromogranin were performed on 32 cases of small cell neuroendocrine carcinoma of the bladder. Staining was scored for intensity (0: no staining; 1: weak; 2: moderate; 3: strong) and proportion of cells stained (0: 0%; 1: >0% to ≤25%; 2: >25% to ≤50%; 3: >50% to ≤75%; 4: >75% to 100%). INSM1 was positive (intensity 1 to 3 or proportion 1 to 4) in 87% (28/32) of cases (20 with intensity 2 to 3, 17 with proportion 3 to 4). CD56, synaptophysin, and chromogranin were positive in 75% (24/32), 60% (19/32), and 44% (14/32) of cases, respectively. INSM1 was negative (n=4) or only showed weak intensity staining (n=7) in 34% (11/32) of cases. INSM1 is a sensitive marker of small cell neuroendocrine differentiation of the urinary tract. However, this study suggests that optimal utilization of INSM1 would be inclusion in a limited panel of stains rather than as a stand-alone screening marker given that it is negative or only shows weak intensity staining in a significant proportion of cases.

Neuroendocrine Carcinoma of the Urinary Bladder: A Large, Retrospective Study From the French Genito-Urinary Tumor Group

BACKGROUND

Neuroendocrine carcinoma of the urinary bladder (NCUB) is rare, accounting for < 1% of bladder cancer cases, with scarce reported data available.

MATERIALS AND METHODS

We retrospectively reviewed the data from patients with NCUB treated at French institutions. The objectives were to describe the patient characteristics, treatments received, and outcomes (ie, disease-free survival [DFS], progression-free survival, overall survival [OS]) and investigate the prognostic factors.

RESULTS

From 1997 to 2017, we included 236 patients, 173 with early-stage NCUB and 63 with advanced-stage NCUB. For those with early-stage disease, the median DFS was better for the patients who had received cisplatin-based chemotherapy compared with carboplatin (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.1-3.46), with no difference found between the neoadjuvant and adjuvant settings (HR, 1.1; 95% CI, 0.61-1.97). The median OS was 36 months (95% CI, 29-43 months) for stage I and II, 26 months (95% CI, 18 months to not reached) for stage IIIA, 16 months (95% CI, 12-21 months) for stage IIIB. The HR for stage IIIB compared with stage I/II was 2.6 (95% CI, 1.5-4.4). The DFS at 6 months was associated with OS (HR, 7.8; 95% CI, 4.1-15.0). For patients with metastases at diagnosis who had received chemotherapy, the median progression-free survival was 9 months (95% CI, 8-11) for first-line cisplatin and 6 months (95% CI, 4-13 months) for carboplatin; the median OS was 13 months (95% CI, 9-15 months). A high-risk Bajorin score (HR, 11.5; 95% CI, 1.2-112.6) and the use of carboplatin (HR, 2.26; 95% CI, 1.03-4.96) were associated with worse outcomes.

CONCLUSIONS

In early-stage disease, a shorter DFS was associated with worse OS, and the use of cisplatin was associated with better OS. For the patients with metastases at diagnosis, a high-risk Bajorin score and the use of carboplatin were associated with worse outcomes.

Primary small cell carcinoma of the urinary bladder

Small cell carcinoma of the urinary bladder (SCCB) is an extremely rare but aggressive tumour constituting less than 0.7% of all urinary bladder tumours. It is often misdiagnosed as transitional cell carcinoma, owing to the similarities in presentation. Diagnosis of SCCB is based on the WHO criteria for small cell lung carcinoma. A 58-year-old man who had presented with haematuria and burning micturition for 3 months was initially diagnosed as high-grade muscle-invasive urothelial carcinoma based on the TURBT specimen. The patient was put on neoadjuvant chemotherapy, but presented again with haematuria and back pain after 3 months. Imaging studies showed a lesion in the posterolateral wall of the urinary bladder, along with partial collapse and anterior wedging of L1 vertebra. He underwent TURBT, and on the basis of histopathology and immunohistochemistry, a diagnosis of primary SCCB bladder with vertebral metastasis was made.

Update of the International Consultation on Urological Diseases on bladder cancer 2018: non-urothelial cancers of the urinary bladder

PURPOSE

To provide a comprehensive update of the joint consultation of the International Consultation on Urological Diseases (ICUD) for the diagnosis and management of non-urothelial cancer of the urinary bladder.

METHODS

A detailed analysis of the literature was conducted reporting on the epidemiology, etiology, diagnosis, treatment and outcomes of non-urothelial cancer of the urinary bladder. An international, multidisciplinary expert committee evaluated and graded the evidence according to the Oxford System of Evidence-based Medicine modified by the ICUD.

RESULTS

The major non-urothelial cancers of the urinary bladder are squamous cell carcinoma, adenocarcinoma, and neuroendocrine tumors. Several other non-urothelial tumors are rare but important to identify because of their aggressive behavior when compared to urothelial bladder tumors. Radical cystectomy and urinary diversion, preceded by neoadjuvant radiation or chemotherapy in some of these tumors, is the main method or treatment for resectable disease. Adjuvant therapy is not usually successful and no novel targeted or immunotherapeutic agents have been identified to provide benefit. Patients with small cell neuroendocrine tumors of the bladder should be offered chemotherapy before surgery. Because non-urothelial cancers are usually locally advanced and/or metastatic at the time of diagnosis, 5-year survival is generally poor.

CONCLUSIONS

Non-urothelial cancers of the urinary bladder are rare and mostly lack established protocols for treatment. The prognosis of most of these tumors is poor because they are usually advanced at the time of diagnosis. A multimodal treatment approach should be considered to improve outcomes.

[PRIMARY SMALL CELL NEUROENDOCRINE CARCINOMA OF THE URETER]

Primary small cell neuroendocrine carcinoma of the upper urinary tract is a rare disease that is associated with a poor prognosis. An 81-year-old man was diagnosed with carcinoma of the stomach and underwent laparoscopic distal gastrectomy. Computed tomography (CT) revealed carcinoma of the left ureter and left hydronephrosis. The patient was diagnosed with carcinoma of the left ureter (cT2N0M0) and left laparoscopic radical nephroureterectomy was performed via a retroperitoneal approach. The pathological diagnosis was left ureter carcinoma (small cell neuroendocrine carcinoma, pT3). He was treated with four courses of the CE regimen (carboplatin area under the curve: 5, intravenously [IV] on day 1 and etoposide [80 mg/m²], IV on days 1-3). There is no evidence of disease at 21 months after radical nephroureterectomy.

Clinicopathologic and Immunohistochemical Study of Combined Small Cell Carcinoma and Urothelial Carcinoma Molecular Subtype

Muscle invasive bladder cancer, an aggressive disease with heterogeneous molecular profiles, has recently been subclassified into three major molecular subtypes -basal, luminal and "p53-like" urothelial carcinomas (UCas), which bear prognostic and therapeutic implication. Similar to breast cancer, basal and luminal subtype UCas are designated by basal (CK5/14) and luminal (CK20) markers. The "p53-like" subtype presents with wild-type p53 gene with upregulated p53 pathways and is implicated in chemoresistance. Urinary bladder is one of the most common primary sites of extrapulmonary small cell carcinoma (SmCC). Bladder SmCC frequently coexists with UCa; however, the relation of SmCC with specific UCa molecular subtypes has not been studied. The aim of this study is to investigate the clinicopathology and immunophenotypes of the combined SmCC and UCa molecular subtypes. A total of 22 combined SmCC and UCa cases were studied for the clinicopathology and immunohistochemical (IHC) profiles by luminal and basal cell markers as well as Her2/Neu and p53. Our results demonstrated that all the urinary bladder SmCCs were associated with high grade UCas. They were more commonly seen in older male patients with a smoking history and had a poor prognosis. Based on the reported molecular subtyping, the UCas could be immunohistochemically subclassified into luminal, basal, dual and null types, which showed different clinicopathologic and IHC features. Compared to non-SmCC associated UCa, the subtypes of UCa in the combined SmCCs and UCas were characterized by: 1) Although overall luminal type was still relatively more common in men, basal marker-expressing subtypes were significantly increased in incidence and were more common in women. 2) Her2/Neu overexpression was more commonly observed in luminal than basal cell marker-expressing UCas. 3) IHC overexpression of p53 was common in all the subtypes, with UCas and SmCCs sharing the same p53 expression pattern. Although limited by relatively a small number of cases, the results of this study will enhance our understanding of the combined SmCC and UCa entity and potentially lead to a future therapeutic management.

Clinical analysis of small cell carcinoma of the bladder in Chinese: nine case reports and literature reviews

Background

Small cell carcinoma of the bladder (SCCB) is a kind of rare and highly aggressive tumor that is present in an advanced stage and has a propensity for early metastasis. The main presenting symptom of SCCB is hematuria. Surgery, chemotherapy, and radiotherapy, either alone or as a part of combined therapy, have been used as the treatment. The aim of this study is to present our experience with 9 SCCB patients who were treated with different modalities and to share the findings upon reviewing the literatures for patients with SCCB reported in 56 literatures in Chinese.

Methods

We retrospectively evaluated 9 patients with SCCB from February 1980 to January 2014 in Tongji Hospital, Huazhong University of Science and Technology. The general characteristics, clinical manifestations, the pathological and immunohistochemical characteristics, treatment options, and prognostication in those eligible manuscripts were analyzed. In order to gain a better understanding of the clinical features of SCCB, another 119 cases reported in 56 articles were reviewed together (from January 1979 to March 2014). And a retrospective analysis was performed.

Results

All the 9 cases in Tongji Hospital were successfully operated, and the tissue samples were sent for pathological examination. All the tumor tissues contained small cell carcinoma components. 4 cases coexisted with other histologic types of bladder cancers, and 2 out of the 9 cases had three different cell components. All the patients had muscle invasion, and 4 cases showed lymph nodes metastasis, 3 cases showed invasion of neighboring structures (seminal vesicle or uterus), and 1 case was highly suspected of liver metastasis. Immunohistochemistry results showed that PCK, Syn, NSE, and CD56 were all positive, but LCA was negative. After operations, 3 patients underwent chemotherapy and only 1 patient received postoperative radiotherapy. Patients were followed up, ranging from 3 to 84 months and the median survival time was 33 months. The leading cause of death was tumor recurrence or metastasis, while 2 patients are still alive. According to the published literature, the pathological stage, immunohistochemical markers, and survival curves of all the 128 cases were also retrospectively analyzed.

Conclusions

SCCB is different from transitional cell carcinoma (TCC) of the bladder. It has its unique cytology, immunohistochemistry, and ultrastructural features. Its diagnosis relies on pathological examination and immunohistochemistry. The current main treatment for SCCB is surgery combined with chemotherapy. Since the disease develops early metastasis easily, the overall prognosis of this cancer is poor. Further research need to clarify the molecular pathogenesis so that novel therapies can be developed for this rare cancer.

Mixed Neuroendocrine-Nonneuroendocrine Neoplasms (MiNENs): Unifying the Concept of a Heterogeneous Group of Neoplasms

The wide application of immunohistochemistry to the study of tumors has led to the recognition that epithelial neoplasms composed of both a neuroendocrine and nonneuroendocrine component are not as rare as traditionally believed. It has been recommended that mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are classified as only those in which either component represents at least 30 % of the lesion but this cutoff has not been universally accepted. Moreover, since their pathogenetic and clinical features are still unclear, mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are not included as a separate clinicopathological entity in most WHO classifications, although they have been observed in virtually all organs. In the WHO classification of digestive tumors, mixed neuroendocrine-nonneuroendocrine neoplasm is considered a specific type and is defined as mixed adenoneuroendocrine carcinoma, a definition that has not been accepted for other organs. In fact, this term does not adequately convey the morphological and biological heterogeneity of digestive mixed neoplasms and has created some misunderstanding among both pathologists and clinicians. In the present study, we have reviewed the literature on mixed neuroendocrine-nonneuroendocrine epithelial neoplasms reported in the pituitary, thyroid, nasal cavity, larynx, lung, digestive system, urinary system, male and female genital organs, and skin to give the reader an overview of the most important clinicopathological features and morphological criteria for diagnosing each entity. We also propose to use the term "mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN)" to define and to unify the concept of this heterogeneous group of neoplasms, which show different characteristics mainly depending on the type of neuroendocrine and nonneuroendocrine components.

Cytomorphologic and Immunophenotypic Profile of a Cohort of Small Cell Carcinoma of the Urinary Bladder

BACKGROUND

The incidence of primary small cell carcinoma (SCC) of the urinary bladder is extremely rare. We sought to analyze the cytologic and immunophenotypic features of SCC of the urinary bladder in urine and reassert the importance of cytologic examination of urine specimens for diagnosis of this tumor.

METHODS

We studied the clinical and cytomorphologic features in the presurgical urine specimens (4 voided urine and 2 bladder-washing specimens) of histopathologically and immunohistochemically proven cases of SCC of the urinary bladder.

RESULTS

There were 6 cases, all males, with an age range of 61-81 years. On cytologic and histopathologic examination, typical SCC morphology was present in all cases. On immunohistochemistry, synaptophysin and CD56 were positive in all 6 cases, while chromogranin was positive in only 3. The Ki-67 labeling index ranged from 30 to 100%.

CONCLUSIONS

SCC should be kept in the differential diagnosis, when high-grade urothelial carcinoma is suspected in a urine cytology specimen, as this distinction has important therapeutic and prognostic implications. Therefore, a careful observation and, if required, the use of an appropriate immunocytochemical panel on the presurgical urine specimens can lead to a correct diagnosis.

Small cell carcinoma of the urinary bladder: changing trends in the current literature

Background Extrapulmonary small cell carcinoma (SmCC), also known as oat cell carcinoma or small cell neuroendocrine carcinoma, is characterized by an aggressive clinical course with early metastasis pattern and a short life expectancy. So far, there is no prospective, data-based case-control study due to its low incidence. The purpose of this paper is to discuss the epidemiology, morphopathology, clinical characteristics, differential diagnosis and treatment of bladder SmCC in the light of the literature. Scope PubMed and American Society of Clinical Oncology Meeting abstracts were searched according to the following keywords: 'extrapulmonary SmCC', 'bladder cancer', and 'therapeutic approach'. The last search was performed on 1 October 2015. Some additional papers were determined by reviewing references of the appropriate articles. Most of the data regarding small cell carcinoma of the urinary bladder (SmCCB) were found to be based on the retrospective trials. Findings Bladder SmCC is more frequent in men and usually appears in the seventh to eighth decades. Macroscopic hematuria is the most common clinical symptom. The diagnosis of SmCCB is performed based on the same criteria determined by the WHO classification for the diagnosis of small cell lung carcinoma (SCLC). Prognosis is closely correlated with the stage at presentation. Although the prognosis of the disease is poor, a long survival can be achieved particularly by radical surgery following neoadjuvant chemotherapy in patients with early stage tumors. Cystectomy is still the current standard local treatment. However, cystectomy alone is not sufficient. Chemotherapy and definitive radiotherapy should be preferred for limited disease in patients who are not candidate for surgery. Conclusion Considering the poor prognosis of the disease, further studies are needed to determine the optimal treatment options and new molecular markers in the way of early diagnosis and favorable outcomes. Prospective, multicenter, randomized studies are required to evaluate the role of neoadjuvant chemotherapy followed either by surgery or radiotherapy.

Primary Small Cell Carcinoma in Urinary Bladder: A Rare Case

Small cell carcinoma of bladder, which does not have a common and accepted treatment protocol, is a rare and highly aggressive tumor. It is mostly pulmonary originated; however, it can rarely be seen in extrapulmonary sites. We presented an interesting and uncommon case, in which the transitional cell tumor was found in the transurethral resection specimen, but the small cell carcinoma was detected in the final radical cystectomy material.

Genitourinary small cell malignancies: prostate and bladder

Small cell carcinoma is an aggressive malignancy often associated with dismal prognosis due to the presence of advanced disease. Small cell malignancies, initially described in the lung (small cell carcinoma of the lung), can occur in extrapulmonary sites, such as prostate (small cell carcinoma of the prostate) and bladder (small cell carcinoma of the bladder), with similar clinicopathologic outcomes. There has been a paradigm shift in the management of small cell carcinoma of the lung from initial surgical treatment to use of chemotherapy followed by local therapies. Such treatment modalities have been applied to small cell carcinoma of the prostate and the bladder, with promise in improving patient survival. Use of platinum-based combination chemotherapy followed by surgical resection and/or radiation offers the most benefit. Further investigation at the molecular level may offer targeted therapies earlier in the course of the disease.

Neuroendocrine Carcinoma of the Kidney and Bladder with Loss of Heterozygosity and Changes in Chromosome 3 Copy Number

Patient: Female, 77

Final Diagnosis: Neuroendocrine carcinoma of the kidney and bladder

Symptoms: Right lumbar pain

Medication: None

Clinical Procedure: CT • needele biopsy of renal tumor • transyrethral resection of bladder tumor

Specialty: Urology

Long-term results of radical cystectomy and role of adjuvant chemotherapy for small cell carcinoma of the bladder

OBJECTIVE

To review our experience with radical cystectomy for small cell carcinoma of the bladder, to compare outcomes with a cohort of patients with urothelial carcinoma, and to determine the effect of adjuvant chemotherapy and pathology re-review in this setting.

METHODS

Among 2427 patients who underwent radical cystectomy, 68 patients had small cell carcinoma of the bladder. Patients with small cell carcinoma of the bladder were compared with an unmatched cohort of 1146 patients with urothelial carcinoma, and were then matched (1:2) based on TNM stage. Survival was estimated using the Kaplan-Meier method, and Cox models were used to evaluate association of clinicopathological features with outcome.

RESULTS

Among the 68 small cell carcinoma of the bladder patients, 37 (54%) were found to have small cell carcinoma of the bladder only after pathology re-review. Patients with small cell carcinoma of the bladder had a higher rate of advanced (pT3/4) tumor stage (84% vs 46%; P < 0.0001) and pN+ disease (37% vs 20%; P = 0.001) compared with patients with urothelial carcinoma. When matched for stage and lymph node status, no significant difference in 5-year cancer-specific survival was observed between the two groups (27% vs 29%; P = 0.64). Among small cell carcinoma of the bladder patients, those receiving adjuvant chemotherapy had improved 5-year overall survival compared with patients who did not receive adjuvant chemotherapy (43% vs 20%; P = 0.03), and a trend toward superior cancer-specific survival (40% vs 23%; P = 0.07).

CONCLUSIONS

Small cell carcinoma of the bladder is often an unrecognized pathological entity, which is associated with a higher rate of locally advanced and N+ disease. However, although when matched for pathological features, survival outcomes appear similar to urothelial carcinoma. Small cell carcinoma of the bladder patients receiving adjuvant chemotherapy had improved overall survival and cancer-specific survival, and these results require further investigation.

Small cell carcinoma of the bladder

Small cell carcinoma of the urinary bladder is an extremely aggressive and rare tumor. Even though small cell carcinoma most commonly arises from the lungs there are several reports of small cell carcinoma in extrapulmonary sites. Due to its low frequency there is no well-established management for this disease. We report the case of a 61 year-old man with small cell carcinoma of the bladder who underwent radical cystectomy following neoadjuvant chemotherapy. We also reviewed the literature for the optimal treatment strategy.

Small cell carcinoma of the urinary bladder and prostate: Cytological analyses of four cases with emphasis on the usefulness of cytological examination

The occurrence of small cell carcinoma in the urinary bladder and prostate is rare. Only a few reports on the cytological features of small cell carcinoma of the urinary bladder in the urine specimen have been documented and, moreover, the urinary cytological features of prostate small cell carcinoma have been rarely reported. In this study, we analyzed the cytological features of four cases of small cell carcinoma of the urinary bladder and prostate, and discussed the usefulness of cytological examination of urine specimen for this type of tumor. This study included two urinary bladder and two prostate small cell carcinoma cases. Analyses of the cytological features of these cases revealed the following: i) the background was mostly inflammatory and necrotic material was also occasionally observed; ii) numerous tumor cells were present in two cases, whereas only a few neoplastic cells were observed in the remaining cases; iii) the neoplastic cells were small in size, had scant cytoplasm and a high nuclear/cytoplasmic ratio, and were arranged in small clusters or occasionally as single cells; iv) the tumor cell clusters showed prominent nuclear moldings; and v) the nuclei of the neoplastic cells were round to oval in shape with finely granular chromatin containing inconspicuous nucleoli. The cytological features of small cell carcinoma in the urine specimen are characteristic. Therefore, careful observation of the urine specimen may lead to a correct diagnosis of small cell carcinoma of the urinary bladder and, moreover, cytodiagnosis of prostate small cell carcinoma may also be possible.