Prostatic adenocarcinoma with carcinoidal features producing adrenocorticotropic syndrome. Immunohistochemical study and review of the literature

Reporting Trends, Practices, and Resource Utilization in Neuroendocrine Tumors of the Prostate Gland: A Survey among Thirty-Nine Genitourinary Pathologists

Background. Neuroendocrine differentiation in the prostate gland ranges from clinically insignificant neuroendocrine differentiation detected with markers in an otherwise conventional prostatic adenocarcinoma to a lethal high-grade small/large cell neuroendocrine carcinoma. The concept of neuroendocrine differentiation in prostatic adenocarcinoma has gained considerable importance due to its prognostic and therapeutic ramifications and pathologists play a pivotal role in its recognition. However, its awareness, reporting, and resource utilization practice patterns among pathologists are largely unknown. Methods. Representative examples of different spectrums of neuroendocrine differentiation along with a detailed questionnaire were shared among 39 urologic pathologists using the survey monkey software. Participants were specifically questioned about the use and awareness of the 2016 WHO classification of neuroendocrine tumors of the prostate, understanding of the clinical significance of each entity, and use of different immunohistochemical (IHC) markers. De-identified respondent data were analyzed. Results. A vast majority (90%) of the participants utilize IHC markers to confirm the diagnosis of small cell neuroendocrine carcinoma. A majority (87%) of the respondents were in agreement regarding the utilization of type of IHC markers for small cell neuroendocrine carcinoma for which 85% of the pathologists agreed that determination of the site of origin of a high-grade neuroendocrine carcinoma is not critical, as these are treated similarly. In the setting of mixed carcinomas, 62% of respondents indicated that they provide quantification and grading of the acinar component. There were varied responses regarding the prognostic implication of focal neuroendocrine cells in an otherwise conventional acinar adenocarcinoma and for Paneth cell-like differentiation. The classification of large cell neuroendocrine carcinoma was highly varied, with only 38% agreement in the illustrated case. Finally, despite the recommendation not to perform neuroendocrine markers in the absence of morphologic evidence of neuroendocrine differentiation, 62% would routinely utilize IHC in the work-up of a Gleason score 5 + 5 = 10 acinar adenocarcinoma and its differentiation from high-grade neuroendocrine carcinoma. Conclusion. There is a disparity in the practice utilization patterns among the urologic pathologists with regard to diagnosing high-grade neuroendocrine carcinoma and in understanding the clinical significance of focal neuroendocrine cells in an otherwise conventional acinar adenocarcinoma and Paneth cell-like neuroendocrine differentiation. There seems to have a trend towards overutilization of IHC to determine neuroendocrine differentiation in the absence of neuroendocrine features on morphology. The survey results suggest a need for further refinement and development of standardized guidelines for the classification and reporting of neuroendocrine differentiation in the prostate gland.

ACTH-secreting metastatic prostate cancer with neuroendocrine differentiation

Cushing's syndrome (CS) due to ectopic adrenocorticotropic hormone (ACTH) secretion (EAS) can result from a variety of tumours and rarely from those of prostatic origin. We present a male patient in his early 60s with ACTH-secreting metastatic prostate adenocarcinoma with neuroendocrine differentiation (ICD-O code 8574/3) years after prostatectomy and androgen-deprivation therapy, initially presenting with Cushingoid features. After open radical prostatectomy and bilateral orchiectomy for disease recurrence, the patient was found to have metastatic liver and bone lesions highly suggestive of metastatic prostatic cancer. About 10% of cells on liver biopsy expressed ACTH, a finding consistent with EAS as the cause of CS. His stay was complicated with multiple infections and ultimate death. Hence, we report a case of metastatic prostate adenocarcinoma with neuroendocrine differentiation who presented with CS. We also emphasize the importance of adequate and timely treatment.

ECTOPIC ADRENOCORTICOTROPIC HORMONE SYNDROME DUE TO METASTATIC PROSTATE CANCER WITH NEUROENDOCRINE DIFFERENTIATION

Objective

Neuroendocrine differentiation of prostate cancer can result in ectopic adrenocorticotropic hormone (ACTH) secretion (EAS) and Cushing syndrome. The aim of this report is to highlight this unusual mechanism of hypercortisolism and its management.

Methods

We report a 73-year-old patient with a history of prostate adenocarcinoma who presented with severe weakness, hyperglycemia, and hypokalemia caused by EAS.

Results

Diagnostic workup showed elevated 24-hour urine cortisol and ACTH levels consistent with EAS. Fluorodeoxyglucose positron emission tomography-computed tomography revealed a hypermetabolic mass in the prostate and metastatic lesions to the liver and bones. Liver biopsy was consistent with small cell carcinoma with positive immunostaining for ACTH. Pleural fluid analysis was consistent with high-grade neuroendocrine carcinoma. The patient underwent chemotherapy with carboplatin and etoposide. Hypercortisolism was treated with ketoconazole, metyrapone, mifepristone, and spironolactone. He suffered complications including opportunistic infections, deep venous thrombosis, and delirium. Given his poor prognosis and clinical decline, the patient opted for comfort measures only in a hospice facility.

Conclusion

Treatment-related neuroendocrine differentiation of prostate cancer is an emerging entity that may be associated with paraneoplastic syndromes including EAS.

Molecular analysis and literature-based hypothesis of an immunonegative prostate small cell carcinoma causing ectopic ACTH syndrome

Ectopic ACTH syndrome (EAS) due to a prostate small cell carcinoma (SCC) is very rare with only 26 cases reported to date and has a poor prognosis. We here describe another case of this disorder that was clinically typical based on prior reports as it showed hypercortisolemia and severe hypokalemia with multiple metastasis. However, our current case of prostate SCC causing EAS is the first to display negative immunostaining for ACTH despite detectable POMC mRNA expression in the primary lesion. ACTH immunonegativity is thought to be associated with a more aggressive disease course and a poorer prognosis although there are few studies of the underlying mechanisms. We explored two possibilities for this finding in our current patient: aberrant POMC processing prevented immunodetection with an anti-ACTH antibody; and the ACTH content per cell was below the threshold for immunodetection due to its rapid secretion or low synthesis. The aberrant processing theory was thought to be less likely because of immunonegative findings even using anti-POMC/ACTH antibodies. As the plasma ACTH levels in our patient were comparable with those reported for previous immunopositive prostate EAS cases, we speculated that the depletion of ACTH may be caused not only by rapid secretion but also by low production levels as a sign of de-differentiation. De-differentiation may therefore explain the mechanism underlying the negative correlation between immunoreactivity for ACTH in EAS and disease aggressiveness. We believe that our present findings will be of use in future prospective studies aimed at confirming the mechanism of immunonegativity.

Neuroendocrine tumors of the prostate

Neuroendocrine (NE) differentiation in tumors of the prostate or in the setting of prostate cancer (PCa) is rare. A survey of these lesions is presented, including usual PCa with focal NE marker-positive cells, Paneth cell-like change, prostatic 'carcinoid', high-grade NE carcinoma, as well as other tumors that do not fit neatly into these categories. The most significant clinical and pathologic features, emerging molecular evidence and the importance of differentiating NE tumors involving the prostate from secondary involvement are highlighted.

Severe Cushing's syndrome due to small cell prostate carcinoma: a case and review of literature

Cushing's syndrome (CS) due to ectopic adrenocorticotrophic hormone (ACTH) is associated with a variety of tumours most of which arise in the thorax or abdomen. Prostate carcinoma is a rare but important cause of rapidly progressive CS. To report a case of severe CS due to ACTH production from prostate neuroendocrine carcinoma and summarise previous published cases. A 71-year-old male presented with profound hypokalaemia, oedema and new onset hypertension. The patient reported two weeks of weight gain, muscle weakness, labile mood and insomnia. CS due to ectopic ACTH production was confirmed with failure to suppress cortisol levels following low- and high-dose dexamethasone suppression tests in the presence of a markedly elevated ACTH and a normal pituitary MRI. Computed tomography demonstrated an enlarged prostate with features of malignancy, confirmed by MRI. Subsequent prostatic biopsy confirmed neuroendocrine carcinoma of small cell type and conventional adenocarcinoma of the prostate. Adrenal steroidogenesis blockade was commenced using ketoconazole and metyrapone. Complete biochemical control of CS and evidence of disease regression on imaging occurred after four cycles of chemotherapy with carboplatin and etoposide. By the sixth cycle, the patient demonstrated radiological progression followed by recurrence of CS and died nine months after initial presentation. Prostate neuroendocrine carcinoma is a rare cause of CS that can be rapidly fatal, and early aggressive treatment of the CS is important. In CS where the cause of EAS is unable to be identified, a pelvic source should be considered and imaging of the pelvis carefully reviewed.

An Unusual Case of Resistant Hypokalaemia in a Patient with Large Bowel Obstruction Secondary to Neuroendocrine Carcinoma of the Prostate

Neuroendocrine Carcinoma of the Prostate (NECP) is rare and only few cases have been reported, constituting less than 0.5% of prostatic malignancies. We report a rare case of large bowel obstruction from NECP posing a further challenge in management due to resistant hypokalaemia. A 70-year-old man presented with clinical signs of large bowel obstruction who was known to have prostatic carcinoma three years ago, treated initially with hormone therapy then chemoradiation. The blood profile showed a severe hypokalaemia and CT scan revealed liver and lung metastases apart from confirming large bowel obstruction from local invasion of NECP. Severe hypokalaemia was believed to be caused by paraneoplastic syndrome from tumor burden or by recent administration of Etoposide. Intensive potassium correction through a central venous access in maximal doses of 150 mmol/24 hours under cardiac monitoring finally raised serum potassium to 3.8 mmol/L. This safe period allowed us to perform a trephine colostomy at the left iliac fossa. The postoperative period was relatively uneventful. This first case report is presenting a rare cause of large bowel obstruction from a neuroendocrine carcinoma of prostate and highlights the importance of an early, intensive correction of electrolytes in patients with large tumor burden from NECP.

Small Cell Carcinoma of the Prostate

An 82-year-old man, who 7 years previously had been treated for adenocarcinoma of the prostate, was found to have developed a small cell (oat cell) carcinoma of prostate, which presented with liver metastases. The expression of different neuroendo crine markers in these carcinomas is presented, the histogenesis of small cell carcinoma is discussed, and the relevant literature is reviewed. The importance of the recognition of small cell carcinoma of the prostate is emphasized because of the influence of small cell carcinoma on the prognosis. Int J Surg Pathol 2(3):237-244, 1995

Establishing prostate cancer patient derived xenografts: lessons learned from older studies

BACKGROUND

Understanding the progression of prostate cancer to androgen-independence/castrate resistance and development of preclinical testing models are important for developing new prostate cancer therapies. This report describes studies performed 30 years ago, which demonstrate utility and shortfalls of xenografting to preclinical modeling.

METHODS

We subcutaneously implanted male nude mice with small prostate cancer fragments from transurethral resection of the prostate (TURP) from 29 patients. Successful xenografts were passaged into new host mice. They were characterized using histology, immunohistochemistry for marker expression, flow cytometry for ploidy status, and in some cases by electron microscopy and response to testosterone. Two xenografts were karyotyped by G-banding.

RESULTS

Tissues from 3/29 donors (10%) gave rise to xenografts that were successfully serially passaged in vivo. Two, (UCRU-PR-1, which subsequently was replaced by a mouse fibrosarcoma, and UCRU-PR-2, which combined epithelial and neuroendocrine features) have been described. UCRU-PR-4 line was a poorly differentiated prostatic adenocarcinoma derived from a patient who had undergone estrogen therapy and bilateral castration after his cancer relapsed. Histologically, this comprised diffusely infiltrating small acinar cell carcinoma with more solid aggregates of poorly differentiated adenocarcinoma. The xenografted line showed histology consistent with a poorly differentiated adenocarcinoma and stained positively for prostatic acid phosphatase (PAcP), epithelial membrane antigen (EMA) and the cytokeratin cocktail, CAM5.2, with weak staining for prostate specific antigen (PSA). The line failed to grow in female nude mice. Castration of three male nude mice after xenograft establishment resulted in cessation of growth in one, growth regression in another and transient growth in another, suggesting that some cells had retained androgen sensitivity. The karyotype (from passage 1) was 43-46, XY, dic(1;12)(p11;p11), der(3)t(3:?5)(q13;q13), -5, inv(7)(p15q35) x2, +add(7)(p13), add(8)(p22), add(11)(p14), add(13)(p11), add(20)(p12), -22, +r4[cp8].

CONCLUSIONS

Xenografts provide a clinically relevant model of prostate cancer, although establishing serially transplantable prostate cancer patient derived xenografts is challenging and requires rigorous characterization and high quality starting material. Xenografting from advanced prostate cancer is more likely to succeed, as xenografting from well differentiated, localized disease has not been achieved in our experience. Strong translational correlations can be demonstrated between the clinical disease state and the xenograft model.

Proposed morphologic classification of prostate cancer with neuroendocrine differentiation

On July 31, 2013, the Prostate Cancer Foundation assembled a working committee on the molecular biology and pathologic classification of neuroendocrine (NE) differentiation in prostate cancer. New clinical and molecular data emerging from prostate cancers treated by contemporary androgen deprivation therapies, as well as primary lesions, have highlighted the need for refinement of diagnostic terminology to encompass the full spectrum of NE differentiation. The classification system consists of: Usual prostate adenocarcinoma with NE differentiation; 2) Adenocarcinoma with Paneth cell NE differentiation; 3) Carcinoid tumor; 4) Small cell carcinoma; 5) Large cell NE carcinoma; and 5) Mixed NE carcinoma - acinar adenocarcinoma. The article also highlights "prostate carcinoma with overlapping features of small cell carcinoma and acinar adenocarcinoma" and "castrate-resistant prostate cancer with small cell cancer-like clinical presentation". It is envisioned that specific criteria associated with the refined diagnostic terminology will lead to clinically relevant pathologic diagnoses that will stimulate further clinical and molecular investigation and identification of appropriate targeted therapies.

Variants and unusual patterns of prostate cancer: clinicopathologic and differential diagnostic considerations

Beyond the typical acinar morphology observed in the majority of prostatic adenocarcinomas, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be classified as: (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features and/or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details a number of variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Unusual cause of ectopic secretion of adrenocorticotropic hormone: Cushing syndrome attributable to small cell prostate cancer

OBJECTIVE

To report a rare cause of ectopic adrenocorticotropic hormone (ACTH) secretion leading to severe Cushing syndrome.

METHODS

We describe the clinical presentation and management of a case of Cushing syndrome attributable to ectopic ACTH secretion from small cell cancer of the prostate.

RESULTS

In a 70-year-old man with hypertension and diabetes, congestive heart failure developed. He was found to have severe hypokalemia (serum potassium, 1.7 mEq/L) and a huge pelvic mass on a computed tomographic scan performed because of a complaint of urinary retention. Transurethral biopsy of the prostate showed features of small cell prostate cancer. Hormonal evaluation revealed a high urine free cortisol excretion of 6,214.5 microg/d (reference range, 36 to 137), confirming the diagnosis of Cushing syndrome. A serum ACTH level was elevated at 316 ng/dL (reference range, 10 to 52). An overnight high-dose (8 mg orally) dexamethasone suppression test was positive (serum cortisol levels were 43.2 and 41 microg/dL before and after suppression, respectively), and magnetic resonance imaging of the pituitary gland disclosed no abnormalities. A prostate biopsy specimen showed small cell prostate cancer with positive staining for ACTH. The tumor was found to be unresectable, and the poor condition of the patient did not allow for bilateral adrenalectomy. He was treated with ketoconazole and metyrapone, which yielded good temporary control of his Cushing syndrome (24-hour urine free cortisol decreased to 55.2 microg/d). He received 1 cycle of chemotherapy (etoposide and cisplatin), but he died 6 months later as a result of sepsis.

CONCLUSION

Small cell prostate cancer is a rare subtype that can be associated with ectopic secretion of ACTH and severe Cushing syndrome. With this subtype of prostate cancer, Cushing syndrome should be considered and appropriately managed.

Hepsin cooperates with MYC in the progression of adenocarcinoma in a prostate cancer mouse model

BACKGROUND

Hepsin is a cell surface protease that is over-expressed in more than 90% of human prostate cancer cases. The previously developed Probasin-hepsin/Large Probasin-T antigen (PB-hepsin/LPB-Tag) bigenic mouse model of prostate cancer demonstrates that hepsin promotes primary tumors that are a mixture of adenocarcinoma and neuroendocrine (NE) lesions, and metastases that are NE in nature. However, since the majority of human prostate tumors are adenocarcinomas, the contribution of hepsin in the progression of adenocarcinoma requires further investigation.

METHODS

We crossed the PB-hepsin mice with PB-Hi-myc transgenic mouse model of prostate adenocarcinoma and characterized the tumor progression in the resulting PB-hepsin/PB-Hi-myc bigenic mice.

RESULTS

We report that PB-hepsin/PB-Hi-myc bigenic mice develop invasive adenocarcinoma at 4.5 months. Further, histological analysis of the 12- to 17-month-old mice revealed that the PB-hepsin/PB-Hi-myc model develops a higher grade adenocarcinoma compared with age-matched tumors expressing only PB-Hi-myc. Consistent with targeting hepsin to the prostate, the PB-hepsin/PB-Hi-myc tumors showed higher hepsin expression as compared to the age-matched myc tumors. Furthermore, endogenous expression of hepsin increased in the PB-Hi-myc mice as the tumors progressed.

CONCLUSIONS

Although we did not detect any metastases from the prostates in either the PB-hepsin/PB-Hi-myc or the PB-Hi-myc mice, our data suggests that hepsin and myc cooperate during the progression to high-grade prostatic adenocarcinoma.

Variants and Unusual Patterns of Prostate Cancer

Beyond the typical acinar morphology observed in most prostatic adenocarcinoma, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be further classified into (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details several variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Neuroendocrine lesions of the genitourinary tract

Neuroendocrine differentiation in tumors of the upper and lower urinary tracts, prostate, and testis is rare. The current review surveys the most significant pathologic and clinical features of primary neuroendocrine lesions at these sites, with emphasis on the cell types from which they derive. As many tumors in this spectrum often bear strong morphologic resemblance to similar neoplasms in other organs, the importance of considering secondary involvement of the genitourinary tract cannot be overstated.

Carcinoid tumors of the urinary tract and prostate

CONTEXT

Carcinoid tumors are exceedingly rare in the genitourinary tract and may occur in the kidney, urinary bladder, urethra, or prostate.

OBJECTIVE

To review the clinical and pathologic features of carcinoid tumors occurring in the urinary tract and prostate.

DATA SOURCES

We searched the English language literature using MEDLINE and Ovid.

CONCLUSIONS

Carcinoid tumors of the urinary tract and prostate share similar morphologic features with their counterparts in other organs. The differential diagnosis includes metastatic carcinoid tumor, paraganglioma, and nested variants of urothelial and prostatic carcinomas. Correlation of the clinical presentation and histopathologic features (including the immunohistochemical profile) will ensure accurate diagnosis of these rare tumors.

Low-grade neuroendocrine carcinoma (carcinoid tumor) of the prostate

A case of primary, prostatic, low-grade neuroendocrine carcinoma (carcinoid tumor) is described. The patient is an 86-year-old man who presented with symptoms of gross hematuria of several days' duration. Physical examination and a bladder biopsy specimen revealed the presence of a primary adenocarcinoma of the bladder with invasion into the muscularis propria. A cystoprostatectomy was performed, which revealed the presence of invasive adenocarcinoma of the bladder. Prostatic sampling demonstrated the presence of a low-grade neuroendocrine carcinoma (carcinoid tumor) and a small focus of well-differentiated conventional adenocarcinoma. Immunohistochemical studies using neuroendocrine markers clearly demarcated the presence of the neuroendocrine tumor. The case presented herein highlights the ubiquitous distribution of neuroendocrine neoplasms along the male genitourinary tract and the presence of 3 separate neoplasms in the genitourinary tract.

Neuroendocrine cells in the normal, hyperplastic and neoplastic prostate

Neuroendocrine cells can be demonstrated in normal, hyperplastic and neoplastic prostatic tissues. The products secreted by these cells can be used as tissue and/or serum markers but may also have biological effects. Neuroendocrine cells in prostate cancer most probably do not contain the androgen receptor and are therefore primarily androgen independent. Some of the neuropeptides secreted by the neuroendocrine cells may act as growth factor by activation of membrane receptors in an autocrine-paracrine fashion or by ligand-independent activation of the androgen receptor in neighboring non-neuroendocrine cells. Evidence is accumulating from experiments with tumor models that neuropeptides indeed can influence the growth of prostatic tumor cells. Future research on neuroendocrine differentiation may answer some questions concerning the biological behavior of clinical prostatic tumors.

Neurologic complications of patients with small cell prostate carcinoma. Report of two cases

BACKGROUND

Primary small cell carcinoma arising in organs other than the lung were thought to be relatively rare. However, with the increasing technical sophistication of pathology departments, tumors with foci of small cell neuroendocrine components are being identified more frequently. The pattern of disease involvement and optimal treatment have yet to be defined.

METHODS

Two cases of primary small cell carcinoma of the prostate are described in which patients previously had unreported degrees of central nervous system disease.

RESULTS

Approximately 75 cases of small cell carcinoma of the prostate have been reported. Neurologic complications have been reported infrequently, although a variety of neurologic paraneoplastic sequelae have been noted. However, carcinomatous meningitis or development of intraductal tumors without concomitant vertebral bone disease has never been reported. These tumors respond poorly to hormonal therapy alone, and recent reports suggest optimal therapeutic strategies may involve combination hormone and chemotherapy.

CONCLUSION

Small cell carcinoma of the prostate must be recognized when it arises de novo or with components of adenocarcinoma because the prognoses and response to treatment differs from the more common adenocarcinomas of the prostate.

Prostatic marker-negative amphicrine carcinoma of the prostate

It has been shown that prostatic adenocarcinoma differentiation correlates with prostatic-specific marker and neuroendocrine expression; that is, the more undifferentiated the tumor, the less it expresses prostatic markers and the more neuroendocrine cells are found in it. Complete absence of prostatic markers together with marked neuroendocrine expression has been associated with small cell morphology. This report describes a case of a metastatic, prostatic marker-negative, non-small cell prostatic adenocarcinoma with a prominent neuroendocrine component. The architecturally well-organized luminal-exocrine cells appeared ultrastructurally undifferentiated, however, displaying an almost empty cytoplasm. This contrasted with the prostatic marker-positive control cases of prostatic carcinoma, which contained relatively numerous cytoplasmic vacuoles. The neuroendocrine cells could be identified by light microscopy as eosinophilic cells. The number of the latter cells was markedly increased in the metastatic foci compared with the primary tumor. Light microscopically and ultrastructurally, the eosinophilic cells in this case differed from the Paneth-like cells described in prostatic carcinoma in previous reports. This case provides support for the general concept of multidirectional differentiation in human epithelial cancers and in particular for the association of poor tumor differentiation with neuroendocrine expression in prostatic carcinoma. In addition, in contrast with previous reports describing absence of basement membrane in metastatic foci of prostatic carcinoma, in the current case well-formed basal laminae were identified.

A major solid undifferentiated carcinoma pattern correlates with tumour progression in locally advanced prostatic carcinoma

Solid undifferentiated carcinoma was the major microscopic pattern in 24 prostatic carcinomas, 12 of which were clinically recurrent. Tumour cells were uniform, with moderately hyperchromatic nuclei and indistinct cytoplasm, and were arranged in solid or focally irregular aggregates. In areas, the tumour cells were large with vesicular nuclei, nucleoli and more abundant cytoplasm. In previous specimens, solid undifferentiated carcinoma was absent or was a minor pattern. Twenty of 23 cases showed prostate specific antigen and prostatic acid phosphatase immunoreactivity, and nine of 17 cases contained scattered argyrophilic or chromogranin-immunoreactive cells. On proliferating cell nuclear antigen immunostaining of 12 specimens, the mean tumour proliferative fraction in solid undifferentiated carcinoma (range: 10.5-18%) was greater than in areas of grade 3 prostatic carcinoma (range: 3-6%). In all 22 stage C and D cases, there was a close correlation with clinical evidence of tumour progression, and the overall 2-year survival rate was only 16.7%. It is concluded that a major solid undifferentiated pattern correlates with increased biological aggressiveness and a poor prognosis in locally advanced prostatic carcinoma.

Neuroendocrine differentiation in carcinoma of the prostate. Diagnostic, prognostic, and therapeutic implications

Endocrine-paracrine cells of the prostate (also known as APUD or neuroendocrine cells) constitute, in addition to the basal and exocrine secretory cells, a third population of highly specialized epithelial cells in the prostate gland. These endocrine-paracrine cells contain, and most likely secrete, serotonin and calcitonin, as well as variety of other peptides. Little is known of the functional role of these cells, but they probably subserve a paracrine or local regulatory role. They may also regulate via endocrine, lumencrine, or neurocrine mechanisms. These endocrine-paracrine cells probably play a significant role during prostatic growth and differentiation as well as regulating the secretory process of the mature gland. Neuroendocrine differentiation in prostatic carcinoma occurs in the form of the relatively rare small cell carcinoma and carcinoid or carcinoid-like tumor, but most commonly as focal neuroendocrine differentiation in a conventional prostatic adenocarcinoma that is a very frequent, if not ubiquitous phenomenon, and reflects tumor cell heterogeneity mimicking the normal differentiation process. The world's literature on neuroendocrine differentiation in prostatic carcinoma is reviewed. Neuroendocrine differentiation in all types of prostatic carcinoma appears to correlate with a poor prognosis. This correlation is probably multifactorial and may relate to a positive correlation with grade, a direct resistance to hormonal manipulation, and/or autocrine/paracrine growth factor activity due to the secretion of neuroendocrine products. Neuron-specific enolase and chromogranin, as well as other neuroendocrine products, may be useful as serum markers in patients with prostatic carcinoma with neuroendocrine differentiation. New therapeutic strategies need to be developed to treat these tumors. This includes the use of specialized protocols that have been effective against neuroendocrine carcinomas arising in other organ systems.

Small cell carcinoma of prostate: effectiveness of hormonal versus chemotherapy

Small cell carcinoma of the prostate is rare and associated with a rapidly fatal course. Since 1977, 47 cases have been reported in the world literature with data from 3 additional cases presented herein. The purpose of our review was to determine the effectiveness of hormonal versus chemotherapy. Thirty-four of the 50 cases have known clinical histories. Four patients were not treated, and all were dead of their disease within an average of 2.75 months. Six patients were eliminated from our review because small cell carcinoma was discovered at autopsy. Another 5 cases were omitted because hormonal +/- chemotherapy had already been given for a previous diagnosis of adenocarcinoma, but no specific therapy was given once the small cell carcinoma developed. Of the remaining 19 cases, only 2 have survived. One is still alive forty-three months after hormonal treatment, and another is alive with disease six months after the initiation of hormonal therapy and chemotherapy. Five patients were given hormonal therapy only, and none of them responded. In 4 patients chemotherapy was given after hormonal therapy had failed, and they too died of their disease within a short period of time. However, an additional 8 patients were treated with immediate chemotherapy +/- hormonal therapy and had substantially longer clinical remissions. Therefore, although small cell carcinoma is a uniformly fatal disease, immediate chemotherapy should be considered to promote better clinical remissions.

Neuroendocrine differentiation in human prostatic carcinoma

Endocrine-paracrine (APUD, neuroendocrine) cells are located in the prostatic ductal and acinar epithelium. These cells are of the open and closed type and have dendritic processes. There is a wide range of secretory granule morphology presumably indicating a variety of different cell "types." Secretory immunoreactive peptides include serotonin, calcitonin (and related peptides), somatostatin, bombesin-like, thyroid-stimulating hormone-like (beta chain), and alpha-glycoprotein chain-like. These cells may function by endocrine, paracrine, neurocrine, and lumencrine mechanisms and play an important regulatory role both during growth and differentiation of the prostate as well as in the secretory process of the mature gland. Neuroendocrine differentiation in prostatic carcinoma is a frequent occurrence and manifests itself in several forms, including (1) small cell carcinoma, (2) carcinoid and carcinoid-like tumors, and (3) conventional adenocarcinoma with focal neuroendocrine differentiation. This latter pattern is the most common, and there is evidence that all or nearly all prostatic adenocarcinomas show at least some focal neuroendocrine differentiation. A review of the world's literature on this topic is included. Neuroendocrine differentiation generally portends a poorer prognosis but may also correlate directly with the grade. There is some evidence to suggest that neoplastic cells with neuroendocrine differentiation are resistant to hormonal therapy. Eutopic and ectopic hormone production may allow screening for prostatic carcinoma and/or monitoring for recurrence of prostatic carcinomas. Finally, the more basic implications of endocrine-paracrine cells and neuroendocrine differentiation are speculated on in reference to prostatic carcinogenesis and autocrine/paracrine tumor growth factor activity.

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.

Small cell carcinoma of the renal pelvis: a clinicopathological, morphological and immunohistochemical study of 2 cases

Two women, 62 and 66 years old, with combined small cell carcinoma and transitional cell carcinoma of the renal pelvis are reported. The clinical picture was similar to that seen in conventional transitional cell carcinoma. A brief review of the literature indicates that in the urinary tract, small cell carcinoma occurs most commonly in the bladder and is exceedingly rare in the renal pelvis; only 2 cases have been reported previously. The morphological spectrum of the small cell carcinomatous component is similar to that seen in lung tumors. Neuroendocrine differentiation of the small cell carcinoma component was supported by a positive immunoreaction to neuron-specific enolase in both cases and to synaptophysin in 1. One patient died with metastases 8 months after diagnosis, and 1 was alive with clinical evidence of lymph node metastases and contralateral papillary transitional cell carcinoma of the renal pelvis 16 months after diagnosis.

Unusual prostatic carcinomas

Over 90% of malignant epithelial tumors of the prostate are common carcinomas. Uncommon or rare prostate carcinomas can histogenetically be related to 4 epithelial types of the prostate: the secretory epithelium, the basal cells, the endocrine cells and the transitional epithelium. The rare, purely mucinous carcinoma and the ductal papillary carcinoma belong to the type of secretory epithelium. The latter is rarely seen in the large central prostatic ducts, it develops more frequently in peripheral ducts and is combined with common prostate carcinoma. The so-called endometrioid carcinomas of the utriculus described in the literature are probably ductal prostate carcinomas. To date no carcinoma has been found in the utriculus. The adenoid cystic carcinoma of the prostate is a basal cell tumor with preponderantly good prognosis. Endocrine cells are disseminated in most common prostate carcinomas. Thereby mixed forms showing both portions of a common adenocarcinoma and of a carcinoid may occur. Pure carcinoids of prostate are rare findings. The small cell carcinoma of the prostate is the highly malignant variant of the endocrine cell type. Immunohistochemically, a multitude of proteohormones are demonstrable in endocrine tumor cells. The ectopic ACTH production with Cushing's syndrome is of particular clinical significance.

Small-cell carcinoma of prostate

Small-cell carcinoma of the prostate is rare, but lethal. We report on 2 cases and review another 6 cases reported in the English literature. Microscopically the tumor may be pure small-cell carcinoma like that seen in the lung or may have a mixed pattern of adenocarcinoma with small-cell carcinoma. This tumor most probably arises from the basal or reserve cells of the prostatic acini. The totipotential basal cells have dual capacity for differentiation into adenocarcinoma and small-cell carcinoma.

Small cell carcinoma of prostate associated with myasthenic (Eaton-Lambert) syndrome

A fifty-eight-year-old white man was diagnosed as having an adenocarcinoma of the prostate (grade III by the U.T.M.D. Anderson Hospital grading system). Five years after the initial diagnosis and three months after signs and symptoms of the myasthenic syndrome of Eaton-Lambert (MSEL), he was found to have a small cell carcinoma of the prostate. Histologic examination showed adenocarcinoma merging into a small cell carcinoma component of intermediate cell type. Immunostaining was positive for neuroendocrine markers--namely, neuron-specific enolase and serotonin--and was limited to the small cell carcinoma component. This is the first report of a patient with small cell carcinoma of the prostate presenting with MSEL. Our findings support prior observations of a strong propensity for small cell carcinoma to be associated with paraneoplastic syndromes, regardless of the initial location of the tumor.

Ectopic hormone production by a prostatic small cell carcinoma xenograft line

The xenograft line, UCRU-PR-2, has been characterized further. Established from a primary human undifferentiated small cell carcinoma of the prostate, it has been maintained as a stable xenograft line in nude mice and is currently in passage 9. The tumor has maintained the features of small cell undifferentiated carcinoma but shows epithelial as well as neuroendocrine characteristics. In this paper, we describe synthesis and secretion of peptide hormones, ACTH, beta-endorphin and somatostatin in vivo and ACTH and beta-endorphin in vitro by the tumor, UCRU-PR-2. This suggests that the gene for proopiomelanocortin is expressed and that processing of the molecule occurs. This line may yield insights into the histogenesis of the subtypes of prostate cancer, and also aid studies of regulation of ectopic hormone production.

Selected ultrastructural aspects of urothelial and prostatic tumors

Ultrastructural techniques have been widely applied in the study of urothelial and prostatic tumors. In the common proliferative diseases affecting the lower urogenital tract, electron microscopy has provided us with a greater understanding of the pathobiology and morphology of these disease processes. Specific diagnostic application, however, has been limited. In the unusual tumors affecting urothelium and prostate such as neuroendocrine carcinoma, carcinosarcoma, and sarcomas, electron microscopy has provided some practical diagnostic information of value in patient management. This paper provides a survey of the fundamental and practical contributions of ultrastructural studies in the prostatic and urothelial areas.

Neuroendocrine differentiation in prostatic carcinoma

Specimens from 53 cases of prostatic carcinoma obtained during total prostatectomy or transurethral resection of prostate were analyzed for neuroendocrine differentiation with immunocytochemical tests for serotonin, neuron-specific enolase, and chromogranin as well as with the Churukian-Schenk argyrophil reaction. Forty-seven per cent (25 of 53) of the prostatic carcinomas were positive for neuroendocrine differentiation, usually with an overlapping combination of these techniques. Nine per cent (five cases) contained areas with numerous neuroendocrine cells, 11 per cent (six cases) had focal scattered neuroendocrine cells, and 26 per cent (14 cases) had rare neuroendocrine cells. The positive cases spanned the histologic spectrum of prostatic adenocarcinoma; histologically none resembled a carcinoid tumor or a small cell carcinoma. Positive cases were further studied with a battery of antisera to 12 polypeptide hormones. Immunoreactivity to only bombesin (one case) and calcitonin (two cases) was detected. In five cases, neuroendocrine differentiation was studied by electron microscopy and verified at the ultrastructural level.

Small cell carcinoma of the prostate. Part I. A clinicopathologic study of 20 cases

Clinical information and histological slides of 20 cases of small cell carcinoma of the prostate seen at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston over a 23-year period were reviewed. Patient's ages ranged from 30 to 89 years (median, 67 years). In nine cases, pure adenocarcinoma of the prostate preceded recognition of the small cell component by 7 months to 8 years (median, 18 months); five of these were initially at Stage A. There was a small cell component at presentation in 11 cases (10, Stage D). Small cell carcinoma was merging with the adenocarcinoma in 11 cases and represented 30% to 90% of total tumor volume. Eleven of 20 patients died of their disease. Those presenting initially with a pure adenocarcinoma survived between 7 months and 9 years (median, 24 months). After the recognition of the small cell carcinoma component, regardless of a prior history of adenocarcinoma, death followed within 1.5 years (median, 5 months). This study suggests a biologic difference in behavior in prostatic carcinoma containing a small cell carcinoma component. The small cell component may manifest early or late in the disease.

Flow cytometric and karyotypic analysis of a primary small cell carcinoma of the prostate: a xenografted cell line

A human small cell undifferentiated carcinoma of the prostate, xenografted in nude mice, was analyzed both cytogenetically and by DNA flow cytometry. The DNA content of the line indicated its stability on serial passage, and was consistent with the cytogenetic findings. The banded karyotype was hypodiploid with nonrandom losses of chromosomes #6, #7, #10, and #13. Structural rearrangements involved chromosomes #1 and #2, and there were three unidentified markers. The findings were compared with those described in other types of prostatic carcinoma.

Small cell carcinoma of the prostate. II. Immunohistochemical and electron microscopic studies of 18 cases

To evaluate the histogenesis of small cell carcinoma of the prostate, 18 cases of this tumor (9 pure small cell and 9 combined adeno- and small cell carcinoma) were studied using immunohistochemical methods. Seven of the small cell components also were assessed by electron microscopic examination. Using neuron-specific enolase (NSE), prostatic acid phosphatase (PAP), and prostate-specific antigen (PSA) on tissue sections, three distinctive immunostaining patterns of small cell carcinoma components were identified: staining positive for NSE and negative for PSA and PAP (10 cases), staining positive for PSA and PAP and negative for NSE (3 cases), and negative reaction for all three antigens (5 cases). Electron microscopic study demonstrated neurosecretory granules in two cases. Based on the immunostaining and electron microscopic findings, small cell carcinomas of the prostate appear to be a heterogeneous group of tumors. Some of them are neuroendocrine carcinomas whereas others are poorly differentiated adenocarcinomas or, possibly, reserve cell carcinomas. Differences in immunostaining patterns or presence and absence of adenocarcinoma component do not reflect any differences in the uniformly poor prognosis of small cell carcinomas, in which median survivals is 7.7 months. The authors believe that, because of such heterogeneity, small cell carcinomas of the prostate arise from multipotential prostatic epithelium and that an origin from specific neuroendocrine cells need not be implicated.

Prostatic adenocarcinoma evolving into carcinoid: selective effect of hormonal treatment?

Two patients, aged 72 and 65 years, each underwent two prostatic resections spaced four and two years apart, respectively. In both cases the earlier procedure showed widespread adenocarcinoma with only occasional endocrine cells, while tissue from the later operations showed prostatic carcinoids. It is suggested that the conventional adenocarcinomas were sensitive to hormonal manipulations used in treatment, but that the originally sparse carcinoid components were resistant to this form of treatment and hence became the predominant tumours. These findings imply that endocrine differentiation in prostatic carcinoma leads to lack of sex steroid sensitivity.

Calcitonin immunoreactive cells in prostate gland and cloacal derived tissues

Calcitonin- and serotonin-storing cells have been immunocharacterized in prostate gland, urethra, urinary bladder and anal canal. In addition, a few hCG and somatostatin immunoreactive cells have been detected in prostate gland. All these cells were dispersed throughout the epithelial lining. In the anal canal, calcitonin cells were exclusively confined to the anal ducts and anal transitional zone epithelium. Calcitonin and serotonin cells were seen in some examples of prostatic adenocarcinoma. Combined techniques most often showed coexistence of calcitonin and serotonin immunoreactivities in the same endocrine cell. hCG immunoreactive cells corresponded to a subpopulation of serotonin-, calcitonin-storing cells. Calcitonin and serotonin cells were present in most organs which originated from the cloaca. In this territory, this distinctive endocrine pattern could be regarded as an excellent marker of cloacal derived tissues. These tissues constitute an additional site for extrathyroid C-cells. It is likely that calcitonin cells are a component of some prostatic adenocarcinomas.

Small cell carcinoma of the prostate gland with inappropriate antidiuretic hormone secretion: morphological, immunohistochemical and clinical expressions

Small cell carcinomas of the prostate gland are rare, and their histogenesis and clinical behavior remain poorly defined. We report a case with antidiuretic hormone secretion, which demonstrates direct transformation of the adenocarcinoma into the small cell component. The adenocarcinoma reacted positively for prostatic antigen, and negatively for carcinoembryonic antigen and neuron specific enolase, whereas the small cell component was negative for prostatic antigen, and positive for carcinoembryonic antigen and neuron specific enolase. At biopsy this was interpreted as denoting 2 separate tumors: one of prostatic and the other of nonprostatic origin. The clinical course was rapidly fatal but otherwise manifested the metastatic pattern of prostatic carcinoma. We caution that immunohistochemical reactions may be misleading if not interpreted in the context of other findings in the case. This case is labeled as a small cell carcinoma rather than a poorly differentiated adenocarcinoma of the ordinary type because the tumor exhibited morphological, immunohistochemical and biological features typical for that neoplasm.