Primary renal carcinoid tumors: clinicopathologic features of 9 cases with emphasis on novel immunohistochemical findings

Prognostic factors and treatment impact on overall survival in patients with renal neuroendocrine tumour

Background

Renal neuroendocrine neoplasms (R-NEN) are exceptionally rare tumours characterized by high mortality rates.

Objective

The objective of this study is to analyse prognostic factors and treatment impact on overall survival in patients with R-NEN.

Design setting and participants

We identified all patients with R-NEN in the National Cancer Database (NCDB) from 2004 to 2019 and identified prognostic factors for improved survival.

Results and limitations

Of 542 R-NEN cases, 166 (31%) were neuroendocrine tumour grade 1 (NET-G1), 14 (3%) were neuroendocrine tumour grade 2 (NET-G2), 169 (31%) were neuroendocrine carcinoma (NEC-NOS), 18 (3%) were large cell neuroendocrine carcinoma (LC-NEC) and 175 (32%) were small cell neuroendocrine carcinoma (SC-NEC). Median overall survival for all patients in the study was 44.88 months (SE, 4.265; 95% CI, 27.57-62.19). Median overall survival was 7.89 months (SE 0.67; 95% CI, 6.58-9.20) for patients without surgical intervention and 136.61 months (SE 16.44; 95% CI, 104.38-168.84, p < 0.001) for patients who underwent surgery. Increased age (HR, 1.05; 95% CI, 1.03-1.06; p < 0.001), T4 stage disease (HR, 3.17; 95% CI, 1.96-5.1; p < 0.001), NEC-NOS histology (HR, 2.82; 95% CI, 1.64-4.86; p < 0.001), LC-NEC histology (HR, 2.73; 95% CI, 1.04-7.17; p = 0.041) and SC-NEC histology (HR, 5.17; 95% CI, 2.95-9.05; p < 0.001) were all positive predictors of worsening overall survival. The main limitation of the study is its retrospective design.

Conclusion

R-NEN is an aggressive tumour characterized by high mortality rates. Surgery continues to be the mainstay of treatment and has shown to provide a survival benefit for most patients.

Patient Summary

R-NEN is composed of several tumour histologies that differ based on their aggressiveness with NEC-NOS and SC-NEC being the most lethal. Surgery, predominantly through minimally invasive approaches, is the mainstay of treatment and has a clear survival benefit.

Renal Neuroendocrine Tumor: A Case Report with Evaluation of Grading Criteria and Relationship with Carbonic Anhydrase 9 Immunoreactivity

Neuroendocrine tumors (NETs) are only exceptionally primary to the kidney. At present, scant information is known regarding the behavior and prognosis of renal NETs, especially according to the assessment of grading parameters used for NETs originating from other more commonplace sites such as the pancreas and lungs. There are only rare reports of grade assessment in renal NETs, with most of these reports relying upon now antiquated World Health Organization gastroenteropancreatic and lung/thymus criteria. As an additional prognostic factor, positive CA9 staining in NETs may correlate with elevated grade, stage and risk of metastasis while serving as a potential target of chemotherapy and immunotherapy and indicator of Von Hippel-Lindau Syndrome. Rarer still are descriptions of renal NETs presenting with renal cell carcinoma in the ipsilateral or contralateral kidney. Thus, we present a patient with a primary renal NET of the right kidney with regional lymphovascular invasion and distant metastasis with an emphasis on grading criteria concordant with the World Health Organization 2022 gastroenteropancreatic and lung/thymus systems. In addition, we discuss unusual staining for CA9 in the patient's tumor and a concomitant left kidney clear cell renal cell carcinoma that may act as a clinicopathologic mimic of Von Hippel-Lindau Syndrome.

Primary Small Cell Carcinoma of the Kidney: A Case Study with Emphasis on Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Findings

Small cell carcinoma (SCC) of the kidney is included in extrapulmonary SCC which is a group of extremely rare but highly aggressive cancers. There have been only a few case reports and small retrospective series in the literature describing the malignancy in kidneys. Most of the published reports describe the entity as a variant mixed with other tumor subtypes such as urothelial carcinoma, adenocarcinoma, and squamous cell carcinoma. Pure-form SCC in kidneys is exceedingly rare. Fluorodeoxyglucose positron emission tomography-computed tomography plays an essential role in the accurate staging evaluation of this cancer.

Primary Renal Well-Differentiated Neuroendocrine Tumors: Analyis of Six Cases from a Tertiary Care Center in North India with Review of Literature

Well-differentiated renal neuroendocrine tumors are rare tumors. As their biologic behavior is not fully known, there is a need to know more about these cases. We performed a retrospective chart review of all the cases diagnosed with renal neuroendocrine tumors from January 2016 to December 2020 (five years) in order to understand their clinical features, morphological characteristics and outcome. We included six cases with mean age of 46.2 years (4 males) in our study. All patients underwent radical nephrectomy. Histologically all showed tumor disposed in nests and trabeculae and majority of the tumors belonged to well-differentiated neuroendocrine tumor Grade 1 (WHO criteria of gastoroenteropancreatic neuroendocrine neoplasms). Lymph node metastasis was seen in two cases at the time of clinical presentation. All the tumors were diffusely positive for neuroendocrine tumor markers (synaptophysin, chromogranin, NSE, CD56). Follow-up data was available in all cases with an average follow-up of two years and neither has shown evidence of metastasis or relapse till last follow-up. Role of morphological patterns and immunohistochemical markers is highlighted with the importance of including Ki-67 index in grading them to better understand their outcome.

Imaging of neuroendocrine neoplasms of the male GU tract

Male genitourinary neuroendocrine neoplasms (GU-NENs) are rare, without any definite imaging characteristics. The WHO classified neuroendocrine neoplasms in the 2016 classification of the tumors of the urinary tract and genital organs along with other GU tumors; however, no pathologic grading system is available as published for gastroenteropancreatic neuroendocrine neoplasms. Often a multimodality approach using cross-sectional imaging techniques, such as molecular imaging and histopathology are implemented to arrive at the diagnosis. This article provides a review of the pathology and imaging features of the male GU-NENs.

Primary renal neuroendocrine neoplasms: A systematic literature review, report of four local cases, and original survival analysis of 63 patients from a national registry 2012-2018

Primary renal neuroendocrine neoplasms (NEN) are rare. We aimed to conduct a systematic review, present local cases, and analyse data from the England's National Cancer Registration and Analysis Service (NCRAS) to provide comprehensive evidence on clinical experience, incidence, and survival to better characterize these tumours. First, a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method; second, a synthesis of local cases; and, finally, a retrospective population-based cohort analysis of renal NEN recorded between 2012 and 2018 on NCRAS were performed. Kaplan-Meier estimator was used to calculate overall survival and Cox proportional hazard regression to identify prognostic factors. Systematic review identified 48 articles and the evidence was summarized and presented. We reported data from four local cases presenting with abdominal and back pain but without carcinoid syndrome. In population-based analysis, we identified 63 cases of renal NEN between 2012 and 2018 from the registry. Age-standardized incidence was 0.09-0.32 per million with a median age of 64 years (interquartile range = 48-72 years). Survival was worse in males and those aged 64 years and over. Five-year survival for renal neuroendocrine tumours (NET) was 69.8% (95% confidence interval = 66.6-72.7) and neuroendocrine carcinomas (NEC) was 38.4% (95% confidence interval = 34.6-42.0). No independent predictive factor was identified in the multivariable analyses. We have given a systematic review of evidence, published local experience, and reported incidence and survival of renal NEN in England for the first time. We have provided clinicians with evidence on diagnosis and proposed a treatment algorithm of theses rare tumours. The incidence and median age of presentation in England is similar to other published series. Renal NET has better survival than renal NEC as expected. A uniform classification system would reduce inconsistencies in reporting and standardize treatment decisions for this neoplasia.

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.

Single institutional experience on primary neuroendocrine neoplasms of the kidney: a rare distinct entity

Primary pure renal neuroendocrine neoplasms (R-NENs) are a distinct and rare entity. Not much is known about the histopathology and biologic behavior of these tumors. We attempted to review the clinicopathologic aspects of these neoplasms encountered at our institution. We performed a retrospective chart review to identify primary pure (not admixed with any other tumor component) R-NENs from institutional Cancer Registry database. Pathologic review of the diagnostic archival slides was done for detailed assessment of the histologic features. R-NENs were classified according to the current WHO system for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). Eight pure R-NEN cases were identified, all unifocal, and most (6/8) involved the right kidney. Three patients had poorly differentiated neuroendocrine carcinoma (NEC), and five had well-differentiated neuroendocrine tumor (NET). All tumors were located near the renal hilum, stained diffusely with synaptophysin, variably with chromogranin, and were negative for renal site-specific marker PAX8 or for markers of renal cell carcinoma. We identified two distinct patterns of growth: one of sheets with interspersed rosettes and the other of large nests with low proliferative crowded centers and peripheral cells with higher proliferation and prominent palisading. Based on Ki-67 proliferative index, the tumors were classifiable into WHO grade 1 or grade 2 (based on GEP-NEN). All three NECs characteristically showed cytologic features intermediate between classic large and small cell type. This is the first comprehensive clinicopathologic study involving the rare group of R-NEN. Classifying and grading them according to the GEP-NEN system is of prognostic significance.

"Man in Istanbul" Lesions of the Urinary Tract (Known Entities in an Unusual Context): Melanoma, Carcinoid Tumors, Epithelioid Angiosarcoma

Certain tumors are more difficult to recognize when they present in an unusual location. Within the urinary tract, primary melanomas, carcinoid tumors, or epithelioid angiosarcoma could present diagnostic challenges due to their infrequent occurrence. This article emphasizes the clinical and histopathologic features of these entities and their differential diagnoses including the immunophenotype and their prognoses.

Metastatic renal carcinoid: To skin, lungs, and pancreas

Carcinoid tumors rarely originate in the urogenital system. We represent a unique case of primary renal carcinoid tumor which was initially diagnosed as renal cell cancer and 10 years later correctly diagnosed as metastatic renal carcinoid.

Primary Carcinoid Tumor of the Renal Pelvis Arising From Intestinal Metaplasia: An Unusual Histogenetic Pathway?

OBJECTIVES

Primary carcinoid tumor of the renal pelvis is a rare neoplasm with few cases reported in the literature. Here we present the clinical and histopathologic findings of a primary carcinoid tumor arising in the left renal pelvis of a horseshoe kidney in a 61-year-old female patient.

MATERIALS AND METHODS

Pathologic features were evaluated with standard hematoxylin and eosin sections and immunohistochemical studies. A literature review was performed to place our case in context to previous reports.

RESULTS

The tumor was associated with intestinal metaplasia with high-grade dysplasia and neuroendocrine hyperplasia. Molecular testing for microsatellite instability and loss of heterozygosity were negative.

CONCLUSIONS

This report portrays a unique presentation of carcinoid tumor arising from intestinal metaplasia of the pelvic urothelium, and supports its histogenesis from urothelial intestinal metaplasia and neuroendocrine hyperplasia.

Primary renal carcinoid tumour with lung metastasis misdiagnosed as renal cell carcinoma

A 58-year-old man with a history of metastatic renal cell carcinoma (RCC) diagnosed 10 years prior, status post right nephrectomy, presented for evaluation of pulmonary nodules. A year after the nephrectomy, he had undergone cutaneous metastasectomy in the right flank area, and a further 2 years later he had had his second cutaneous metastasectomy in the right chest wall. Both cutaneous pathologies had, at the time, shown metastatic neoplasm with histological features compatible with those of the previous renal tumour. He was treated with sorafenib. 3 years later he developed asymptomatic pulmonary nodules, which gradually doubled in size over the next 2.5 years. He underwent bronchoscopy and left lower lobe biopsy. Pathology revealed a metastatic renal carcinoid/neuroendocrine tumour. Second review of the previous renal neoplasm and the cutaneous metastatic pathology showed trabecular architecture, consistent with carcinoid, but mimicking the long parallel arrays that have been described in some cases of papillary RCC.

Renal carcinoid tumor with liver metastasis followed up postoperatively for 9 years

Background

We describe a case of renal carcinoid tumor with liver metastasis followed up postoperatively for 9 years.

Case presentation

A 33-year-old man presented with left flank dull ache. On the abdominal computed tomography, a solid renal mass in the upper portion of the left kidney was detected. The patient had no other abnormal findings, such as suspected distant metastasis or lymph node metastasis. Radical nephrectomy was performed on 14/9/2005. Histological examination and immunohistochemical staining confirm primary renal carcinoid tumor. 9 years after radical nephrectomy, computed tomography of the abdomen demonstrated a 2 cm × 1.8 cm cyst mass in the right liver. Similar pathologic characteristics were found between the renal carcinoid tumor and liver tumor.

Conclusions

We present a primary renal carcinoid tumor with liver metastasis 9 years after radical nephrectomy. With literature review, renal carcinoid tumors exhibit heterogenous behavior.

Neuroendocrine tumors of the kidney: a single institution experience

BACKGROUND

Renal NETs, comprised of carcinoid tumors and small cell carcinomas, are a rare group of neoplasms. The rarity of these tumors pose a diagnostic and therapeutic challenge. Our purpose was to characterize the cases treated at a tertiary cancer center and to evaluate patient outcomes with the available treatment modalities.

PATIENTS AND METHODS

This was a retrospective study of patients with renal NETs seen at The University of Texas M.D. Anderson Cancer Center between January 1, 2001, and January 1, 2011. Patient and tumor data were analyzed using descriptive statistical methods.

RESULTS

Three cases of carcinoid tumors and 6 cases of small cell carcinoma were identified. The median age at diagnosis was 53 years for patients with carcinoid and 65 years for patients with small cell carcinoma. The most common presenting symptoms were back pain, flank pain, and hematuria. The morphological appearance of the tumor cells and their immunohistochemical reactivity for neuroendocrine markers and cytokeratin helped establish the diagnosis. Nephrectomy was the mainstay of treatment for carcinoid tumors, yielding good long-term results, even in the presence of metastases. Surgery and chemotherapy were used for small cell carcinoma of the kidney. The median overall survival for patients with small cell carcinoma of the kidney was 17.3 months.

CONCLUSION

Renal carcinoid tumors are indolent and are associated with prolonged survival, and small cell carcinomas of the kidney are aggressive tumors with relatively short overall survival. Although palliative in nature, cytotoxic chemotherapy is the mainstay of therapy and is best given before surgery.

Atypical carcinoid presenting as dumb-bell-shaped tumour in the normal kidney

Carcinoid tumours are low-grade malignant neoplasms with neuroendocrine differentiation and occur frequently in the gastrointestinal and respiratory tracts. Primary carcinoid tumours of the kidney are rare and a majority of these tumours occur in anomalous kidney and exhibit typical renal carcinoid morphology. We reported a middle-aged man with primary atypical carcinoid tumour occurring in a normal kidney. The patient was diagnosed as having renal cell carcinoma owing to a lack of neuroendocrinal clinical features. Immunohistochemical staining of the nephrectomy specimen helped in the diagnosis of atypical renal carcinoid.

Primary neuroendocrine tumors of the kidney: morphological and molecular alterations of an uncommon malignancy

Primary neuroendocrine (NE) tumors of the kidney (PNRTs) are rare and frequently mistaken for other renal and urothelial cancers. We evaluated morphological and molecular findings of 11 PNRTs classified according to the World Health Organization classification of lung NE tumors. Patients included 5 men and 6 women with a median age of 50 years. These tumors occurred in the left (5/11), right (3/11), and horseshoe (1/11) kidney. The histologic patterns were predominantly solid, trabecular, and pseudoglandular. Lymphovascular invasion and calcification were found in 3 and 1 cases, respectively. There were 2 atypical and 9 typical carcinoids. At the time of surgery, 2 patients with atypical carcinoids had hepatic metastasis, and 1 of the typical carcinoid patients had lymph node metastasis. All cases showed <1% proliferative rate, except 2 cases with hepatic metastasis, which showed 3% to 5% with MIB1/Ki-67 immunostaining. Immunostainings were frequently positive for synaptophysin, chromogranin, CD56, CD99, and neuron-specific enolase. Follow-up data (average 4 years) were available for 6 patients. Two patients with distant metastasis were alive with disease, and four patients with no metastasis were alive without disease. We evaluated the association of PNRT and loss of heterozygosity (LOH) on chromosome 3p21 and found LOH in 2 of 3 cases. However, the comparative genomic hybridization study (2/2) did not demonstrate significant chromosomal imbalances. We conclude that PNRTs are positive for NE markers and may have LOH on chromosome 3p21. PNRTs should be classified as NE tumors in other sites, and proliferative rate can be an indicator of aggressive behavior/metastasis.

Value of PAX2 immunostaining in tumor diagnosis: a review and update

PAX2 is a member of the PAX family of transcription factors that, together with PAX8, is involved in the regulation of the organogenesis of the kidney and the Müllerian system. Recent investigations have demonstrated that, among tumors, PAX2 is commonly expressed in epithelial tumors of the kidney and female genital tract. Although PAX2 expression has also been reported in B-cell lymphomas and rhabdomyosarcomas, especially alveolar rhabdomyosarcomas, it has been suggested that the positivity in these tumors was most probably due to a cross-reactivity of the anti-PAX2 antibody used in those investigations with other members of the PAX protein family. An analysis of published studies indicates that PAX2 sensitivity for epithelial renal neoplasms and epithelial tumors of the female genital tract is lower than that of PAX8. In contrast to the latter marker, however, PAX2 does not appear to be expressed in epithelial tumors of the thyroid gland or thymus. Because of its restricted expression, PAX2 has proved to be a useful immunohistochemical marker with a wide range of diagnostic applications in surgical pathology, some of which will be briefly reviewed.

Primary micro neuroendocrine tumor arising in a horseshoe kidney with cyst: report of a case and review of literature

Abstract

Neuroendocrine tumors are a heterogeneous group of neoplasms that arise from neuroendocrine cells. Primary renal neuroendocrine tumors are among the most unusual of all renal neoplasms, since neuroendocrine cells are not found within normal renal parenchyma. Here, a case of primary micro neuroendocrine tumor (about 4.7 mm*2 mm) arising in the horseshoe kidney with a cyst of a 45-year-old man was reported and a literature review was written.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2121156944757267

A novel case of concurrent renal tumors: chromophobe renal cell carcinoma and carcinoid tumor of the kidney with brief review of renal neuroendocrine tumors

Renal cell carcinoma of chromophobe type is a malignant neoplasm with characteristic large cells that exhibit prominent cell membranes. Primary renal carcinoid tumors are rare tumors with the histological appearance similar to well-differentiated neuroendocrine tumors at other sites. Chromophobe renal cell carcinoma with neuroendocrine differentiation is exceedingly rare. The authors describe a case of a chromophobe renal cell carcinoma and carcinoid tumor of the kidney presenting as distinct masses in the same kidney in a 34-year-old male. The histologic and immunohistochemical features of both the tumors were characteristic with no overlapping features. The carcinoid tumor presented at a higher stage with nodal metastasis. To the best of the authors' knowledge, this is the first case of 2 morphologically distinct tumors, one chromophobe renal cell carcinoma and the other primary carcinoid tumor in the same kidney.