Oat-cell carcinoma of the prostate. Diagnosis, prognosis and therapeutic implications

Neuroendocrine Differentiation in Prostatic Malignancy

Neuroendocrine differentiation in prostatic malignancy is receiving considerable attention; this occurs commonly as a “focal” histological variant and, most rarely, in the form of small cell carcinoma (“oat cell carcinoma”) and carcinoid tumor. In prostate cancer, neuroendocrine differentiation may be the response to androgen deprivation and neuroendocrine products, either biogenic amines or peptides, have been shown to stimulate proliferation of androgen-ablation refractory cancer cells. Serum chromogranins, neuron-specific enolase and other neuroendocrine products as well as 111-In-chromogranin A “three step” immunoscintigraphy and somatostatin-receptor scintigraphy may be useful for predicting tumor behaviour and patient prognosis.

Several of the neuroendocrine products, particularly somatostatin analogues, are candidates for new therapeutic approaches. The paper aims to outline the advances in this field on the basis of the review of the literature.

Small cell carcinoma of the prostate presenting with Cushing Syndrome. A narrative review of an uncommon condition

Small cell carcinoma (SCC) of the prostate is an uncommon condition; there are very few cases in which presenting symptoms are consistent with Cushing Syndrome (CS). We report a new case in which CS triggers the suspicion of an SCC of the prostate and a review of the published cases of SCC of the prostate presenting with CS. The origin of these neoplasms is still unclear. It may be suspected when laboratory features appear in patients diagnosed with prostatic adenocarcinoma which becomes resistant to specific therapy. SCC usually occurs after the 6th decade. Patients suffering SCC of the prostate presenting with CS usually present symptoms such as hypertension, hyperglycemia, alkalosis or hypokalemia; cushingoid phenotype is less frequent. Cortisol and ACTH levels are often high. Prostatic-specific antigen levels are usually normal. CT scan is the preferred imaging test to localize the lesion, but its performance may be improved by adding other tests, such as FDG-PET scan. All patients have metastatic disease at the time of diagnosis. Lymph nodes, liver and bone are the most frequent metastases sites. Surgery and Ketokonazole are the preferred treatments for CS. The prognosis is very poor: 2- and 5-year survival rates are 27.5 and 14.3%, respectively. Key messages When a patient presents with ectopic Cushing Syndrome but lungs are normal, an atypical localization should be suspected. We should suspect a prostatic origin if Cushing Syndrome is accompanied by obstructive inferior urinary tract symptoms or in the setting of a prostatic adenocarcinoma with rapid clinical and radiological progression with relatively low PSA levels. Although no imaging test is preferred to localize these tumors, FDG-PET-TC can be very useful. Hormone marker scintigraphy (e.g. somatostatin) could be used too. As Cushing Syndrome is a paraneoplastic phenomenon, treatment of the underlying disease may help control hypercortisolism manifestations. These tumors are usually metastatic by the time of diagnosis. They have very poor prognosis.

Mixed adenocarcinoma and neuroendocrine prostate cancer: a case report

Background

Neuroendocrine prostate cancer is rare but lethal. It is one of the most common extra pulmonary manifestations of small cell cancer.

Case presentation

Here we present a case report of a 53-year-old male who presents with a mixed adenocarcinoma and neuroendocrine prostate tumor on a background of previously normal prostate-specific antigen (PSA). His initial symptoms prior to diagnosis included decreased urine output and acute kidney injury (AKI).

Conclusion

Neuroendocrine tumor does not elevate the PSA level and hence is often a late finding with a poor prognosis. Special staining on histopathogy is required to reveal this diagnosis.

Unusual and Underappreciated: Small Cell Carcinoma of the Prostate

In recent years, attention has focused on the prognostic importance of neuroendocrine differentiation in prostate cancer. Focal neuroendocrine differentiation in prostatic adenocarcinoma is a frequent finding. Though controversial, the prevalence of neuroendocrine cells has been correlated with higher-grade malignancy and poor prognosis. As with other small cell tumors, production of ectopic neuropeptides has been reported. The rarity of the disease has precluded prospective randomized trials. Therapeutic regimens have mainly been modeled after those for small cell lung carcinoma. Here we review the literature to identify potential diagnostic, therapeutic, and prognostic factors. Evident from this review is the necessity for further research in the biology of small cell carcinoma progression, in order to improve therapy.

[Oat cell carcinoma of the common bile duct]

Oat cell tumors in the common bile duct are extremely rare. We describe the case of a 76-year-old man with skin and mucous jaundice of 15 days' duration without constitutional syndrome. A tumor was diagnosed in the mid portion of the common bile duct. After surgical resection, pathological analysis revealed small-cell (oat cell) carcinoma. The treatment of these tumors is multidisciplinary. Surgery is followed by chemo- and radiotherapy.

Pure primary neuroendocrine tumor of the prostate: a rare entity

An extrapulmonary neuroendocrine tumor arising in the prostate gland has been described in several case series; however, pure and primary prostatic neuroendocrine tumors are very rare, their biologic behavior is not yet well known, and there are only a few reports in the literature describing the clinical features and management of this neoplasm. This article presents the clinicopathologic findings of 2 patients presenting with this disease. The published reports of primary pure neuroendocrine prostate tumors are discussed.

Metastatic Pure Small-Cell Carcinoma of Prostate

Extrapulmonary small-cell carcinoma arising in the prostate gland has been described in several case series and case reports. However, pure small-cell carcinoma of the prostate is rare, and there are only a few reports in literature describing the clinical features and management of this neoplasm. These tumors are highly aggressive and commonly manifest with visceral metastasis at the time of diagnosis. We report a case of metastatic pure prostatic small-cell carcinoma and an associated paraneoplastic polyneuropathy.

Unusual subtypes of prostate cancer

The vast majority of prostatic tumors developing in adult males are adenocarcinomas. For the most part, variations in histology have not received specific designations and, from a practical approach, have had any specific prognostic implications handled through application of the Gleason grading system. Nonetheless, some of the adenocarcinoma variants have specific clinical features and differential diagnoses. Furthermore, there has been some controversy regarding the appropriate application of the Gleason grading scheme in these tumors. In addition, there are carcinomas that are in fact not adenocarcinomas and that should be kept as distinct entities. In this paper, the histologic variants of adenocarcinoma are reviewed with emphasis on clinicopathologic features and the clinical relevance of these subtypes. Other carcinomas that occur in the prostate gland are also discussed again with a focus on the clinicopathologic characteristics.

[Small cell carcinoma of the prostate]

Pure small cell carcinoma of the prostate is rare (less than 1% of all prostatic neoplasm). As a result there are few reports in the literature that describe the salient features and appropriate management of this cancer (less than 200 cases reported). Small cell carcinomas of the prostate are a heterogeneous group of tumors, a number of them have neuroendocrine differentiation and are highly aggressive, commonly with visceral metastases at time of diagnosis. Complete temporary remission has been reported with chemotherapy but this tumor has a poor prognosis. The median overall survival from the time of diagnosis is between 5-17.5 months. We report 2 new cases of small cell carcinoma of the prostate and a review of the literature.