Carcinoid tumor of the kidney with morphologic and immunohistochemical profile of a hindgut endocrine tumor: report of a case

Renal neuroendocrine tumors: clinical and molecular pathology with an emphasis on frequent association with ectopic Cushing syndrome

Renal neuroendocrine tumors (RenNETs) are rare malignancies with largely unknown biology, hormone expression, and genetic abnormalities. This study aims to improve our understanding of the RenNETs with emphasis of functional, hormonal, and genetic features. Surgically resected RenNETs (N = 13) were retrieved, and immunohistochemistry and next-generation sequencing (NGS) were performed in all cases. In addition, all published RenNETs were systematically reviewed. Our cohort (4 men and 9 women, mean age 42, mean tumor size 7.6 cm) included 2 patients with Cushing syndrome (CS). WHO grade (23% G1, 54% G2, and 23% G3) and tumor progression did not correlate. CS-associated RenNETs (CS-RenNETs) showed a solid and eosinophilic histology and stained for ACTH, while the remaining non-functioning tumors had a trabecular pattern and expressed variably hormones somatostatin (91%), pancreatic polypeptide (63%), glucagon (54%), and serotonin (18%). The transcription factors ISL1 and SATB2 were expressed in all non-functioning, but not in CS-RenNETs. NGS revealed no pathogenic alterations or gene fusions. In the literature review (N = 194), 15 (8%) of the patients had hormonal syndromes, in which CS being the most frequent (7/15). Large tumor size and presence of metastasis were associated with shorter patients' survival (p < 0.01). RenNETs present as large tumors with metastases. CS-RenNETs differ through ACTH production and solid-eosinophilic histology from the non-functioning trabecular RenNETs that produce pancreas-related hormones and express ISL1 and SATB2. MEN1 or DAXX/ARTX abnormalities and fusion genes are not detected in RenNETs, indicating a distinct yet unknown molecular pathogenesis.

Primary renal carcinoid tumor: A radiologic review

Carcinoid tumor is the classic famous anonym of neuroendocrine neoplasms. Primary renal carcinoid tumors are extremely rare, first described by Resnick and colleagues in 1966, with fewer than a total of 100 cases reported in the literature. Thus, given the paucity of cases, the clinical and histological behavior is not well understood, impairing the ability to predict prognosis. Computed tomography and (occasionally) octreotide studies are used in the diagnosis and followup of these rare entites. A review of 85 cases in the literature shows that no distinctive imaging features differentiate them from other primary renal masses. The lesions tend to demonstrate a hypodense appearance and do not usually enhance in the arterial phases, but can occasionally calcify. Octreotide scans do not seem to help in the diagnosis; however, they are more commonly used in the postoperative followup. In addition, we report a new case of primary renal carcinoid in a horseshoe kidney.

Primary carcinoid tumour of the kidney: a review of the literature

Context. Primary renal carcinoid tumours are rare. Their pathogenesis is unknown and the clinical presentation is similar to other renal tumours thus posing diagnostic dilemmas for clinicians. Objectives. To review the literature for case reports of primary renal carcinoids. Methods. Literature was extensively searched for case reports for primary renal carcinoids. Reports of metastatic carcinoids to the kidneys were excluded. Results. Approximately less than 90 cases of primary carcinoid tumours of the kidney have been reported in the literature. A total of 29 cases of primary renal carcinoids were reviewed. The mean age of presentation was 48 years (range 29–75) with both right kidney (48.3%) and left kidney (44.8%) being equally affected. 28.6% of the cases reviewed were diagnosed as an incidental finding. The mean followup time was 20 months with 73.1% of patients without evidence of disease after surgical treatment (radical or partial nephrectomy). Primary carcinoid tumours of the kidney are often well differentiated tumours. They are often misdiagnosed because of their rarity and similar presentation with other renal tumours. Conclusions. Primary carcinoid tumours of the kidney are rare tumours with an indolent course with frequent metastasis. Metastatic work up and followup is required in their management.

Primary renal carcinoid: treatment and prognosis

Primary carcinoid tumors of the kidney are very rare, malignant tumors consisting of neuroendocrine cells. The pathogenesis of renal carcinoid is unclear because neuroendocrine cells are not normally found in adult renal parenchyma. Electron microscopy, immunohistochemistry, octreotide scan, positron emission tomography along with conventional radiographic imaging techniques are used in diagnosis and follow-up. Presenting symptoms usually include flank pain and haematuria. Early stage disease is treated with surgery only. However, randomized trials are lacking because of the very low number of reported cases. Thus, the role of debulking surgery, chemotherapy, radiotherapy, octreotide and targeted therapy in the management of advanced disease remains an open question. In this article the clinicopathologic features and prognosis of this very rare disease along with treatment outcomes of the reported cases are reviewed. In addition, we report a new case of a metastatic primary renal atypical carcinoid tumor treated with octreotide therapy.

Renal neuroendocrine tumors

Objectives:

Neuroendocrine tumors (NETs) are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC), and large cell neuroendocrine carcinoma (LCNEC) are exceedingly rare.

Materials and Methods:

The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature.

Results:

Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma) can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease.

Conclusions:

A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

Synchronous primary carcinoid tumor and primary adenocarcinoma arising within mature cystic teratoma of horseshoe kidney: a unique case report and review of the literature

Background

Malignant transformation of mature cystic teratoma is a rare complication. While any of the constituent tissues of a teratoma has the potential to undergo malignant transformation, squamous cell carcinoma is the most commonly associated malignancy. Renal carcinoid tumors are rare and frequently associated with horseshoe kidney and renal teratoma. Renal teratoma rarely presents together with carcinoid tumor or adenocarcinoma. To the best of our knowledge, there has never been a report of renal teratoma coexisting with both carcinoid tumor and adenocarcinoma.

Methods

Here, we present a unique and first case of synchronous primary carcinoid tumor and moderately differentiated adenocarcinoma arising within mature cystic teratoma of horseshoe kidney in a 50-year-old female. Lumbar spine X-ray, done for her complaint of progressive chronic low back pain, accidentally found a large calcification overlying the lower pole of the right kidney. Further radiologic studies revealed horseshoe kidney and a large multiseptated cystic lesion immediately anterior to the right renal pelvis with central calcification and peripheral enhancement. She underwent right partial nephrectomy.

Results

Macroscopically, the encapsulated complex solid and multiloculated cystic tumor with large calcification, focal thickened walls and filled with yellow-tan gelatinous material. Microscopically, the tumor showed coexistent mature cystic teratoma, moderately differentiated adenocarcinoma and carcinoid tumor. Immunohistochemically, alpha-methylacyl-coenzyme A-racemase, calretinin, CD10 and thyroid transcription factor-1 were negative in all the three components of the tumor. The teratomatous cysts lined by ciliated epithelium showed strong staining for cytokeratin 7 and pancytokeratin, and those lined by colonic-like epithelium showed strong staining for CDX2, cytokeratin 20 and pancytokeratin, but both were negative for calretinin. Additionally, the teratomatous cyst wall showed strong staining for smooth muscle actin, and weak staining for carbonic anhydrase IX, CD99, chromogranin and synaptophysin. The adenocarcinoma component was strongly positive for cytokeratin 7 and pancytokeratin, weakly positive for synaptophysin and CD56, and negative for carbonic anhydrase IX, CD99, CDX2, chromogranin, cytokeratin 20 and smooth muscle actin. The carcinoid tumor component was strongly positive for CD56, chromogranin and synaptophysin, weakly positive for pancytokeratin, and negative for carbonic anhydrase IX, CD99, CDX2, cytokeratin 7, cytokeratin 20 and smooth muscle actin. She received no adjuvant therapy and is alive without evidence of disease six months after diagnosis and surgery.

Conclusion

This unique and first case herein presented with synchronous primary carcinoid tumor and primary adenocarcinoma arising within mature cystic teratoma of horseshoe kidney emphasizes the need for thorough sectioning and entire submission for histologic evaluation of mature cystic teratomas, in order to avoid missing multiple additional histogenetically distinct neoplasms.

Renal neuroendocrine tumours: a clinicopathological study

OBJECTIVES

To report cases of primary neuroendocrine tumours (NETs) of the kidney, including carcinoid tumour, large cell neuroendocrine carcinoma (LCNEC) and small cell carcinoma (SCC), which show a wide range of NE differentiation and biological behaviour, and are exceedingly rare.

PATIENTS AND METHODS

The clinicopathological features of all nine renal NETs diagnosed during a 7-year period were reviewed.

RESULTS

Six carcinoids, two SCC and one LCNEC were identified from 2780 kidney tumours. No patient had carcinoid syndrome or other NE symptoms. Three of six carcinoids and no SCC/LCNEC arose in horseshoe kidneys. The mean size of the six carcinoids and three SCC/LCNEC was 4.8 cm and 12.2 cm, respectively. No carcinoid had tumour necrosis or mitosis. By contrast, three SCC/LCNEC had extensive tumour necrosis and brisk mitosis. All renal NETs were positive for synaptophysin but were variably positive for chromogranin and CD56. Three of six carcinoid tumours were confined to the kidney, and four of five patients were disease-free at a mean (range) of 26 (6-74) months. One patient with nodal metastases has had no recurrence and another died with liver metastases. Three patients with SCC/LCNEC each presented with locally advanced disease and extensive lymphadenopathy; two of them died from distant metastasis or local tumour progression, and the third is currently alive with disease.

CONCLUSIONS

Various NETs can occur in the kidney, but rarely. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. The diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical NE markers.

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.

Primary carcinoid tumor arising within mature teratoma of the kidney: report of a rare entity and review of the literature

BACKGROUND

Primary carcinoid tumor arising within mature teratoma of the kidney is extremely rare, and their clinicopathologic features are not well described. Our objective was to further define the clinical features and pathologic spectra of primary carcinoid tumor arising within mature teratoma of the kidney.

METHODS

Six previously reported case reports were identified using MEDLINE and a subsequent bibliographic search of all pertinent reports and reviews was performed. We also searched the electronic medical archival records of our institution and identified one additional unreported case. Data were extracted on the demographics, predisposing factors, clinical presentation, radiographic features, gross pathology, microscopic pathology, immunophenotype, therapy, and outcome of each of these seven cases.

RESULTS

Primary carcinoid tumor arising within mature teratoma of the kidney was found at a mean age of 41.4 years. Of the 7 cases, 3 were female and 4 were male. Two of the 7 cases (28.6%) were associated with horseshoe kidney. It typically presented with abdominal pain without carcinoid syndrome. It typical radiologic appearance was well circumscribed partly calcified Bosniak II-III lesion. Histologically, the carcinoid tumor showed monotonous small round cells arranged in classic anastomosing cords/ribbons intermixed with solid nests. Surgery was curative, no additional treatment was required, no local recurrences occurred, and no metastases occurred in all 7 cases. The 3 cases with available outcome data were alive at the time of publication of their respective cases (mean, 5 months).

CONCLUSION

Primary carcinoid tumor arising within mature teratoma of the kidney is a rare tumor that typically presents with abdominal pain without carcinoid syndrome. It is not associated with local recurrence and metastasis, is surgically curable, and has excellent prognosis.

Primary Carcinoid Tumors of the Kidney

PURPOSE

We describe in detail the features of carcinoid tumors of the kidney. We evaluated possible prognostic factors.

MATERIALS AND METHODS

An extensive search was performed in the medical literature regarding primary carcinoid tumors of the kidney. Epidemiological, clinical, diagnostic, histopathological, therapeutic and prognostic data were evaluated. Several potential risk factors were compared with the incidence of metastases and clinical outcome of the patients.

RESULTS

A total of 56 case reports were reviewed. Median patient age was 49 years. Horseshoe kidneys were present in 17.8% of cases. Incidental diagnosis was made in 28.6% of patients. The most common symptom was abdominal or flank pain and neuroendocrine syndromes occurred with only 12.7% of primary renal carcinoid tumors. Of the patients 73.6% presented with tumors larger than 4 cm. Metastases were present in 45.6% of patients at initial diagnosis and almost 60% with tumors greater than 4 cm had metastases.

CONCLUSIONS

Renal carcinoid is the second most prevalent genitourinary carcinoid in each sex, following testicular carcinoids in men and ovarian tumors in women. Significant adverse prognostic factors include age greater than 40 years, tumor size greater than 4 cm, purely solid tumors on the cut surface, mitotic rate higher than 1/10 high power fields, metastasis at initial diagnosis and tumors extending throughout the renal capsule.

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.

Primary carcinoid tumor in a polycystic kidney

A case of a primary carcinoid tumor within a polycystic kidney is reported. A 51-year-old woman with autosomal dominant polycystic kidney disease (ADPKD) underwent a bilateral nephrectomy because of an infection in her polycystic kidneys. A tumor (1.5 cm in diameter) was incidentally found close to the hilum of the left kidney. Histologically, the tumor exhibited a predominantly trabecular pattern of cuboidal or columnar cells. Grimelius staining showed numerous silver-stained neurosecretory granules in most of the tumor cells; the tumor cells were also positive for chromogranin, synaptophysin, prostatic acid phosphatase (PAP) and neuron-specific enolase (NSE). The tumor was diagnosed as a primary carcinoid tumor of the kidney. Primary renal carcinoid is a very rare neoplasm, and this is the first report of such a lesion arising in a polycystic kidney.

Searching for an intrinsic neuroendocrine cell in the kidney. An immunohistochemical study of the fetal, infantile and adult kidney

The pathogenesis of primary renal carcinoid tumor is unknown. One hypothesis has implied derivation from a yet unrecognized intrinsic neuroendocrine cell in the renal parenchyma/hilum either as a minute endocrineparacrine constituent or resulting from entrapped/misplaced progenitor cells of the so-called dispersed neuroendocrine system during organogenesis. Immunohistochemical staining for chromogranin and serotonin was systematically performed on a whole-mount and geographically mapped normal adult kidney, kidneys from 15 fetuses (age range: 15 to 38 weeks), and renal specimens from 18 infants/children (age range: 7 days to 123 months). Minute paraganglion nests (composed of chromogranin positive/serotonin negative chief cells and S-100 protein positive dendritic cells) were incidentally detected within the renal hilum primitive stroma (unilaterally) of two fetuses at 22 and 26 weeks. Sequestration and persistence of such paraganglion nests during renal growth and maturation would offer a basis for the rare occurrence of extra-adrenal paraganglioma involving the renal hilum/pedicle. Otherwise, no neuroendocrine cell was detected within the renal parenchyma or hilum, therefore not validating/sustaining the aforementioned hypothesis in the pathogenesis of renal carcinoid tumor.

Carcinoid tumor of the kidney. The use of somatostatin receptor scintigraphy in diagnosis and management

Three patients were diagnosed with carcinoid tumors of the kidney. The diagnosis was rendered after biopsy with the assistance of immunohistochemical stains. In all three patients, a pentetreotide scan was helpful in staging. Metastatic disease that was not evident by computed tomography was found in one patient. All three patients are alive with stable or slowly progressive disease at 33, 36, and 40 months. Carcinoid tumors arising from the kidney are rare but must be considered in the differential diagnosis of a renal mass. Immunohistochemical staining is important in the diagnosis of these tumors and the pentetreotide scan contributes to accurate staging.

[A metastatic neuroendocrine tumor with exceptional outcome!]

INTRODUCTION

Neuroendocrine tumors are rare, with poor prognosis when not or poorly differentiated.

EXEGESIS

The authors report the case of a patient who presented with a metastatic poorly differentiated neuroendocrine tumor that was resistant to chemotherapy. The different sites of the carcinoma were lung, pancreas, kidney and lymph nodes. The patient received no treatment and complete spontaneous remission appeared after 21 months. This remission has been lasting for five years.

CONCLUSION

It is the first case of spontaneous remission of a metastatic poorly differentiated neuroendocrine tumor. The evolution and classical sites of neuroendocrine tumors are reviewed. Renal metastasis is also unusual. This report illustrates the fact that neuroendocrine tumors are heterogeneous.

Renal carcinoid and horseshoe kidney: a frequent association of two rare entities--a case report and review of the literature

We report the case of a primary renal carcinoid tumor associated with a horseshoe malformation in a 43-year-old man who presented with testicular pain. The tumor was centrally located and purely solid and had features ascribed to hindgut neuroendocrine neoplasia. The relative risk of developing a carcinoid tumor in a horseshoe kidney is estimated to be x82.

Endocrine carcinoma of the kidney

A 4-cm mass in the right kidney of a 43-year-old female had an endocrine appearance by light microscopy and electron microscopy confirmed this impression, demonstrating the presence of numerous cytoplasmic granules of endocrine caliber. Unusual features were patchy immunoreactivity for chromogranin, and polarity of the granules within the neoplastic cells. Extrarenal extension and liver metastasis were documented.

A primary carcinoid tumor of the kidney: a case report and review of the literature

BACKGROUND

Primary carcinoids are found mostly in the gastrointestinal tract. Primary carcinoid tumor of the kidney is rare; only 28 patients have been reported. Because of the rarity of the lesion, its radiological and clinicopathological features are not well characterized. At the same time, its prognosis and histogenesis is unknown.

METHODS

A 62-year-old patient presented with a carcinoid tumor on the isthmus of the horseshoe kidney. Radiological, clinicopathological, and immunohistochemical tests were performed. The tumor was resected.

RESULTS

Two years later, metastasis were observed in the liver. The metastasis were treated with percutaneous ethanol sclerotherapy (PET).

CONCLUSIONS

To our knowledge, this is the first case of primary renal carcinoid tumor present on the isthmus of the horseshoe kidney and the first case of carcinoid liver metastasis to be treated with PET.

Carcinoid in a horseshoe kidney. Morphology, immunohistochemistry, and cytogenetics

Renal carcinoids are very rare neoplasms. We were able to culture and subsequently karyotype a carcinoid located in the isthmus of a horseshoe kidney, which revealed the following chromosomal pattern: 47,XX, + 13[8]/46,XX,t(13;14)(q31;q11.2)[5]/46,XX[2]. The DNA index was 1. Our results, compared with the sparse data from the literature, suggest that carcinoid of the kidney has no cytogenetic aberrations in common with carcinoids from other anatomical sites reported. On the other hand, numerical and structural aberrations of chromosome 13 seem to play a crucial role in the development of metanephric-derived renal tumors.