Small cell neuroendocrine carcinoma of the urinary bladder. An immunohistochemical and ultrastructural evaluation of 3 cases with a review of the literature

Extrapulmonary Small Cell Carcinoma of the Bladder

Among the many sites for primary small cell cancer is the genitourinary system. The majority of cases have been observed in the bladder and prostate. Small cell carcinoma accounts for less than 1% of all bladder tumors. Definitive predisposing factors are unknown; however, small cell carcinoma of the bladder has been associated with cigarette smoking, long-standing cystitis, bladder calculus, and augmented cystoplasty. Contrary to the early theory of derivation from Kulchitsky cells, it is now believed that small cell carcinoma of the bladder originates from the totipotent stem cells present in the submucosa of the bladder wall. A number of chromosomal aberrations have been reported in small cell cancer of the bladder. There are no specific clinical features that differentiate these patients from transitional cell carcinoma of the bladder; however, some patients may have associated paraneoplastic conditions. Diagnosis is established by cystoscopic-assisted biopsy. Like small cell carcinoma of the lung, small cell carcinoma of the bladder has a propensity for early metastases. There is no standard therapy for small cell carcinoma of the bladder and the prognosis is poor; however, patients treated with cisplatin-based chemotherapy regimens seem to have a better prognosis.

The effect of serotonin and serotonin antagonists on bladder cancer cell proliferation

OBJECTIVE

To investigate the role of serotonin (5-hydroxytryptamine, 5HT) and its antagonists in the proliferation of high-grade bladder cancer cells (HT1376), as high-grade bladder cancer has a rapid rate of progression, invasion and recurrence, and 5HT antagonists inhibit the growth of the prostate cancer cell line (PC3).

MATERIALS AND METHODS

HT1376 (human grade III transitional cell carcinoma) cells were incubated with either 5HT or 5HT antagonists (5HT(1A), 5HT(1B), 5HT(1D), 5HT(2), 5HT(3) and 5HT(4)). After 72 h, cell viability was assessed using the crystal violet assay. The presence of 5HT receptor subtypes on HT1376 cells and sections of human bladder cancer tissue was determined by immunohistochemistry and Western blot analysis.

RESULTS

5HT caused a dose-dependent increase in the proliferation of HT1376 cells. The maximum increase in cell proliferation (12%; 12 samples, P < 0.001) was at 10(-8)m as compared to the control at 72 h. At 10(-4)m, 5HT(1A) antagonist (NAN-190 hydrobromide) and 5HT(1B) antagonist (SB224289 hydrochloride) had a 10% (12 samples, P < 0.001) and 93% (12, P < 0.001) inhibitory effect on HT1376 cell growth, respectively, compared to the control at 72 h. There was immunostaining for 5HT(1A) and 5HT(1B) receptors in HT1376 cells and malignant bladder tissue, confirming the presence of these two receptor subtypes. Western blot analysis showed the presence of 5HT(1A) and 5HT(1B) receptor proteins with bands of 46 kDa and 43 kDa, respectively.

CONCLUSION

5HT(1A) and to a greater extent 5HT(1B) antagonists significantly inhibit bladder cancer cell growth. This effect is probably mediated via the 5HT(1A) and 5HT(1B) receptors. These results highlight the potential use of 5HT(1A) and 5HT(1B) antagonists in the treatment of bladder cancer.

Small cell carcinoma of the bladder: a contemporary clinicopathological study of 51 cases

AIMS

We present 51 cases of primary small cell carcinoma of the bladder in a clinicopathological study with emphasis on features that aid in the initial recognition and diagnosis of small cell carcinoma of the bladder.

METHODS AND RESULTS

The patients were 40 men and 11 women between the ages of 39 and 87 years (mean age 67 years). Clinical data were available in 41 cases. The most common symptomatology was haematuria in 63% of the patients while dysuria was present in 12%. Thirty-eight patients were caucasians; seven patients were Hispanics; two patients were Asian; one patient was African-American; in the three additional patients no racial information was obtained. Biopsy material was obtained in all of the patients. Cystectomy was performed in 20 patients. At diagnosis, clinical stage was as follows: stage I in two (5%), stage II in 18 (44%), stage III in 10 (24%), and stage IV in 11 (27%). Histologically, urothelial carcinoma was present in 70% of the cases, adenocarcinoma in 8%, and squamous cell carcinoma in 10% of the cases. Small cell carcinoma was the only histology present in only 12% of the cases studied. Immunohistochemical studies using chromogranin, synaptophysin and chromogranin were positive in 30-70% of the cases.

CONCLUSIONS

The present study highlights the unusual phenomenon of pure small cell carcinoma of the bladder and its association with other non-small cell carcinomas in that anatomical location. In addition, the study highlights the different modalities employed to treat patients in whom there is a component of small cell carcinoma of the bladder.

Small-cell carcinoma of the urinary bladder: 10-year experience

AIMS

Small-cell carcinoma of the urinary bladder is rarely encountered in clinical practice. We report on our clinical experience with affected patients presenting to our institution from 1986 to 1996.

MATERIALS AND METHODS

We retrospectively analysed 14 pathologically confirmed cases, specifically looking at stage, presenting features, treatment and overall survival. The median age at presentation was 74 years (range 54-91 years).

RESULTS

Ten patients presented with stage III disease, and four patients with stage IV disease (1 = nodal, 3 = distant metastases). Four patients were treated with radical radiotherapy (one patient receiving neoadjuvant chemotherapy) and two underwent a radical cystoprostatectomy. Five patients received palliative bladder radiotherapy and three were too frail for treatment at presentation. The overall median survival was 5 months. Patients receiving radical treatment had a median overall survival of 21 months, with only one long-term survivor.

CONCLUSION

This highly aggressive tumour tends to affect an elderly population who are generally frail and have significant comorbidity. Many are unfit for radical treatment. In patients with disease confined to the pelvis who are able to tolerate radical intervention, the results of local therapy alone are poor. It therefore remains incumbent on treating clinicians to explore means of improving these results. Initial chemotherapy analogous to small-cell lung cancer may offer a durable response with a better chance for long-term survival.

Small cell carcinoma arising from the proximal urethra

Primary neuroendocrine carcinomas of the lower urinary tract are distinctly rare, locally aggressive neoplasms with a high rate of metastasis. We present a case of primary small cell carcinoma of the urethra occurring in a 64-year-old man. The clinical, histological and immunohistochemical features of urethral small cell carcinoma are highlighted with respect to the differential diagnosis of neuroendocrine and other urethral tumors. The possible histogenesis of urethral small cell carcinoma, reported at this location in only a small number of cases, is briefly discussed. We favor an origin from pluripotent epithelial stem cells as one of the possible histogenic pathways.

Primary small cell neuroendocrine carcinoma of urinary bladder: an uncommon entity to be recognized

INTRODUCTION

To describe the clinical presentation, diagnosis and treatment outcome of neuroendocrine carcinoma of urinary bladder.

METHODS

Clinical and pathological findings of 11 patients with diagnosis of small cell neuroendocrine tumour (SCNE) of urinary bladder are reviewed between Jan. 1991 to Jan 2001. Clinical data including age, sex, presenting symptoms, clinical stage at presentation, modality of treatment and outcome were determined. Sections of the tumour were studied by immunohistochemical methods using various antibodies to determine neuroendocrine pattern.

RESULTS

Patient age ranged from 35 to 79 years (mean 60 years). The clinical presentation included, gross hematuria 6, increased urinary frequency and dysuria 3, hydroureteronephrosis with flank pain 2. 3 patients had open exploration for presumed bladder stones by suprapubic route. Undifferentiated carcinoma was the initial report in 2 and associated transitional cell carcinoma in 2 cases. Urinary cytology obtained in 4 patients showed poorly differentiated carcinoma. Immunohistochemistry showed in all cases. 7 patients had radical cystoprostatectomy with adjuvant chemotherapy and 4 patients had combination of chemotherapy and radiotherapy. The survival ranged from 6 months to 30 months (mean 16.5 months).

CONCLUSION

Primary small cell neuroendocrine carcinoma of urinary bladder is an aggressive malignancy with poor long-term outcome. Awareness of clinical presentation with free application of immunocytochemistry is emphasized to diagnose this unusual malignancy at earliest.

Cytomorphology of high-grade neuroendocrine carcinoma of the urinary tract

High-grade neuroendocrine carcinoma of the bladder is a rare malignant tumor with poor prognosis. We present the cytomorphologic features of six retrospectively identified cases which displayed high-grade tumors with neuroendocrine differentiation in bladder washings. Cytology specimens showed small-to-medium-sized tumor cells with powdery chromatin, inconspicuous nucleoli, and ill-defined nuclear membranes. Tumor fragments showed prominent nuclear molding and single-cell necrosis. All cases also revealed a varying proportion of tumor cells resembling the usual transitional-cell carcinoma. Biopsy specimens from five cases demonstrated high-grade transitional-cell carcinoma with areas resembling small-cell carcinoma. In one case the entire tumor consisted of classic small-cell carcinoma and failed to show any areas of transitional-cell differentiation. All cases were positive for neuroendocrine markers. Neuroendocrine carcinomas of the urinary bladder are rare, with cytological features similar to high-grade neuroendocrine carcinomas seen in other organs. They can be accurately diagnosed cytologically, and an awareness of the cytomorphologic features is important.

Combined small and transitional cell carcinoma of the urinary bladder with CA19-9 production

It is well known that extrapulmonary small cell carcinoma, which exhibits morphological features similar to those observed in the lung, occurs in various organs. Clinically, most cases manifest aggressive biological behavior. A case of small cell carcinoma of the urinary bladder producing a high level of serum carbohydrate antigen (CA) 19-9, in which expression was confirmed in cancer cells of small as well as transitional cell carcinoma in the same tumor mass by immunostaining is reported. This paper documents combined small and transitional cell carcinoma of the urinary bladder with CA19-9 production, although it has already been reported that adenocarcinoma or transitional cell carcinoma in various organs frequently expresses CA19-9. Observations suggest that the histogenesis of some cases of combined small and transitional cell carcinoma in the urinary bladder may be the same, as both can produce CA19-9.

Genitourinary small cell carcinoma: determination of clinical and therapeutic factors associated with survival

PURPOSE

We assessed the prognostic impact of genitourinary small cell carcinoma tumor and patient characteristics, and therapy.

MATERIALS AND METHODS

We retrospectively reviewed the records of 180 patients with genitourinary small cell carcinoma in which patient and tumor characteristics, therapy, followup duration and survival status had been documented. Patient age, sex, primary site, histological features, tumor size, stage, locoregional therapy, systemic chemotherapy and hormonal manipulations were analyzed for association with survival.

RESULTS

There were 106 cases of bladder, 60 prostatic, 8 renal and 6 ureteral small cell carcinoma. Median survival was 10.5 months overall, and 7 and 13 months for prostatic and bladder small cell carcinoma, respectively (p <0.0001 log rank analysis). In all cases metastatic disease at presentation (p <0.008, risk ratio 1.9) predicted poor survival on multivariate analysis. Radical surgery (p <0.0001, risk ratio 0.34) and cisplatin chemotherapy (p <0.0001, risk ratio 0.20) were the only factors that predicted improved survival on multivariate analysis. For prostatic small cell carcinoma primary surgical therapy (p <0.012, risk ratio 0.46) was the only parameter that predicted survival on univariate analysis. For bladder small cell carcinoma only cisplatin chemotherapy (p <0.0001, risk ratio 0.15) predicted survival on multivariate analysis.

CONCLUSIONS

Genitourinary small cell carcinoma has a poor prognosis, which is worse in prostatic than bladder disease. Patient and tumor characteristics were not determinants of survival when prostatic and bladder small cell carcinoma were analyzed individually. For prostatic disease only primary surgical therapy was associated with prolonged survival, while for bladder disease cisplatin chemotherapy was associated with a favorable prognosis. We recommend considering primary surgical therapy for prostatic and cisplatin based chemotherapy for bladder small cell carcinoma.

Pathology of transitional cell carcinoma of the bladder and its clinical implications

Transitional cell carcinomas are divided into superficial and muscle-invasive tumors. Most of them are superficial tumors, and approximately 15-20% are muscle-invasive carcinomas. Pathologists play a significant role in diagnosing bladder tumors and in reporting features important for determining prognosis. We will review the cytologic and histopathologic features that help determine prognosis, including depth of invasion, tumor grade, multicentricity, tumor size, and the presence of vascular/lymphatic invasion, blood group antigen expression, proliferative indices, and molecular markers. Brief mention will be made of specimen handling, interpretation, reporting, and histologic variants of transitional cell carcinoma.

The role of synaptic proteins in the pathogenesis of disorders of the central nervous system

Complex sets of nervous system functions are dependent on proper working of the synaptic apparatus, and these functions are regulated by diverse synaptic proteins that are distributed in various subcellular compartments of the synapse. The most extensively studied synaptic proteins are synaptophysin, the synapsins, growth associated protein 43 (GAP-43), SV-2, and p65. Moreover, synaptic terminals contain a great number of other proteins involved in calcium transport, neurotransmission, signaling, growth and plasticity. Probes against various synaptic proteins have recently been used to study synaptic alterations in human disease, as well as in experimental models of neurological disorders. Such probes are useful markers of synaptic function and synaptic population density in the nervous system. For the present, we will review the role of synaptic proteins in the following conditions: Alzheimer's disease (AD) and other disorders including ischemia, disorders where synapse-associated proteins are abnormally accumulated in the nerve terminals, synaptic proteins altered after denervation, and synaptic proteins as markers in neoplastic disorders. The study of the molecular alterations of the synapses and of plasticity might yield important clues as to the mechanisms of neurodegeneration in AD, and of the patterns of presynaptic and dendritic damage under diverse pathological conditions.

Carcinosarcoma of the urinary bladder: a distinct variant characterized by small cell undifferentiated carcinoma with neuroendocrine features

The clinicopathological features of two carcinosarcomas of the urinary bladder are reported. The tumours occurred in a 64- and a 66-year-old patient presenting with haematuria and both were polypoid. The epithelial component was consistent with small cell undifferentiated carcinoma with neuroendocrine differentiation, whereas the sarcomatous component did not display specific features. The carcinomatous component showed immunohistochemical reactivity for different epithelial markers as well as for chromogranin and neuron specific enolase. Conversely, the sarcomatous cells stained strongly for vimentin and in one case for muscle actin and smooth muscle actin. The differential diagnosis of biphasic tumours of the bladder is discussed and the literature reviewed.

Unusual forms of carcinoma of the urinary bladder

Carcinomas of the urinary bladder, which differ histologically from the usual transitional cell carcinoma of the bladder, are reviewed. These tumors, which account for approximately 15% of all bladder carcinomas, have diverse microscopic appearances. They fall into four major categories: variant forms of urothelial (transitional cell) carcinoma, squamous cell carcinoma, adenocarcinoma, and undifferentiated carcinoma. In the first category, the most common are carcinomas with glandular or squamous differentiation. Less common, but more troublesome diagnostically, are variants in which the cells are spindle shaped (sarcomatoid carcinoma), form small cysts (microcystic carcinoma), or differentiate toward trophoblast. In other variants, the stroma has unusual features that may lead to diagnostic difficulty. These are carcinomas with pseudosarcomatous stroma, osseous or cartilaginous metaplasia, or osteoclast-type giant cells. Also reviewed are squamous cell carcinoma and its variant, verrucous carcinoma. Vesical adenocarcinoma has several variants, including signet-ring cell and clear cell types. Finally, the category of undifferentiated carcinoma, including small cell carcinoma, giant cell carcinoma, and lymphoepithelioma-like carcinoma, is discussed.

Small cell carcinoma of the prostate

This report details clinical and pathologic aspects of a patient with small cell undifferentiated carcinoma of the prostate and systemic hyperglucagonemia. A panel of potential serologic markers was evaluated in order to document additional evidence of ectopic hormonal production. Immunocytochemical markers were sought in tissue samples from the primary neoplasm and a lung metastasis. Stains were positive for corticotropin (ACTH) and gastrin in both the prostate and in the lung, but no evidence of excess secretion was documented. These findings are consistent with the notion that neuroendocrine activity is common in undifferentiated small cell carcinomas, regardless of their site of origin.

Synaptophysin. A widespread constituent of small neuroendocrine vesicles and a new tool in tumor diagnosis

Synaptophysin, a vesicular integral membrane protein, is specifically expressed in neuroendocrine tissues. According to cDNA cloning studies, it has a molecular weight of 33,300 Dalton, one potential N-glycosylation site at the vesicle inside, four major hydrophobic domains as well as a C-terminus containing approximately 90 amino acids. The C- and N-termini of synaptophysin are located on the cytoplasmic side of the vesicle membrane. No signal sequence is found. Transfection of non-neuroendocrine cells with synaptophysin cDNA leads to the synthesis of synaptophysin-containing vesicles, which contain this protein in highly enriched form and have biophysical properties similar to presynaptic vesicles of neurons. So far, the vesicular content has only been determined in rat neurons, where classical neurotransmitters such as biogenic amines and transmitter-active amino acids were found. Reconstitution of the purified protein in liposomes suggests a possible channel function of synaptophysin. Using mono- and polyvalent antibodies against synaptophysin, a considerable number of studies in several laboratories have shown that this protein is a reliable marker molecule for neuroendocrine tumors of various degrees of differentiation.

Immunohistochemical examination of 25 cases of Merkel cell carcinoma: a comparison with small cell carcinoma of the lung and oesophagus, and a review of the literature

Merkel cell carcinomas (MCC) were compared to small cell carcinomas of the lung (SCCL) and oesophagus (SCCO). Most MCC were of the intermediate cell type while SCCL and SCCO were usually of the small cell type. Only MCC of trabecular type could be separated from SCCL and SCCO by means of histopathological examination alone. All MCC (25) stained with cytokeratin CAM 5.2, 20 of which in a "paranuclear globular" or combined "paranuclear globular"/diffuse pattern while 17 MCC stained with cytokeratin AE1/AE3. Cytokeratin CAM 5.2 reacted with 60 percent of the SCCL and 86 percent of the SCCO, and cytokeratin AE1/AE3 with 33 and 28 percent respectively. Neurofilament stained 17 MCC in a "paranuclear globular" pattern but none of the SCCL and SCCO. All MCC with a diffuse staining pattern for cytokeratin CAM 5.2 were negative for neurofilament. The results of this study and review of the literature indicate that in most instances Merkel cell carcinoma can be separated from other SCC, pulmonary as well as extrapulmonary, by means of histopathological and, above all, immunohistochemical examinations.

Neuroendocrine differentiation in a case of acinic cell carcinoma of the parotid gland

We report a case of acinic cell carcinoma of the parotid gland with neuroendocrine differentiation. Light microscopically, the tumor appeared as clear cell-type acinic cell carcinoma. In addition, the tumor showed neurosecretory features such as Grimelius positivity and the presence of neurosecretory granules by electron microscopy. We suggest that a tumor cell arising from a stem cell can show simultaneous differentiation to both neuroendocrine and acinic cells.

Synaptophysin and chromogranins/secretogranins--widespread constituents of distinct types of neuroendocrine vesicles and new tools in tumor diagnosis

Normal and neoplastic neuroendocrine (NE) cells have been identified for many years by morphological criteria only. With the advent of immunocytochemistry, antibodies against NE-specific polypeptides have been used to identify NE cells that had been missed by conventional techniques, thus improving the diagnosis of NE cells. In this review article we discuss (i) the biochemical, cell biological and molecular biological data obtained so far for two major types of NE markers, synaptophysin, which is characteristic of the small "transparent-looking" neurosecretory vesicles, and the chromogranins/secretogranins, which are widespread constituents of the larger "dense-cored" secretory granules; (ii) the immunohistochemical data obtained for these marker proteins in normal and neoplastic human NE cells and tissues; and (iii) future possible developments involving these as well as other proteins that are associated with these two distinct secretory organelles of NE cells and may serve as potential markers in NE cell diagnosis.

Morphometric and flow cytometric analysis of small cell undifferentiated carcinoma of the bladder

Eighteen cases of primary small cell carcinoma of the bladder were studied. Three patients survived for two years and one survived for five years, which was significantly worse when compared with poorly differentiated transitional cell carcinoma (WHO grade 3). Aggressive tumour behaviour was independent of the presence of neuroendocrine characteristics. Morphometric analysis showed that the nuclear size, which was comparable with that reported in pulmonary small cell carcinoma, was significantly smaller than in poorly differentiated transitional cell carcinoma. Nuclear morphometry may therefore help identify small cell bladder carcinoma, especially in the absence of neuroendocrine differentiation characteristics. DNA flow cytometry of paraffin wax embedded specimens showed aneuploidy in 14 tumours--five were peritetraploid and two multiple aneuploid--and only three were diploid. Aggressiveness of small cell bladder carcinoma usually coincides with aneuploidy in most cases, but diploid tumours may also follow a rapid, lethal clinical course.

Small cell carcinoma of the urinary bladder. A clinicopathologic, morphometric, immunohistochemical, and ultrastructural study of 18 cases

A multiinstitutional review of 3778 patients with a primary malignancy of the urinary bladder revealed 18 cases (0.48%) of small cell carcinoma which were histologically and morphometrically identical to pulmonary small cell undifferentiated carcinoma. Age, sex, and symptoms at first presentation were comparable to that known in transitional cell carcinoma. Sixteen patients (89%) developed metastatic disease, with most frequent involvement of regional lymph nodes, liver, skeleton, and abdominal cavity. The unfavorable clinical outcome was worse as compared with that reported in advanced stage poorly differentiated transitional cell carcinoma, and was similar to the rapidly fatal outcome of pulmonary small cell undifferentiated carcinoma. Fourteen patients (78%) died by tumor at a mean follow-up period of 9.4 months, and only one patient was free of recurrent disease more than 5 years after cystectomy. This apparent aggressive tumor behavior was independent of the presence of neuroendocrine differentiation characteristics at immunohistochemical (13 cases, 72%) or electron microscopic study (eight cases, 44%). The prolonged survival periods (15-38 months) of the five patients who received combination chemotherapy suggested that, just as in small cell lung carcinoma, chemotherapy may be profitable. A unified concept of histogenesis of bladder cancer with a common origin from a multipotent mucosal stem cell is proposed.