Primary adenocarcinoma of the renal pelvis: histologic features of a stepwise process from intestinal hyperplasia to dysplasia in a patient with chronic renal abscess

Primary adenocarcinoma of the renal pelvis: An uncommon tumor, a case report

INTRODUCTION AND IMPORTANCE

Primary adenocarcinoma of the renal pelvis is a rare and unique malignancy, representing a small fraction of renal cancers and posing significant diagnostic challenges due to its unusual presentation and similarity in symptoms to more common excretory tract disorders. This case emphasizes the importance of distinguishing this pathology from other renal neoplasms and metastatic adenocarcinomas that originate in the digestive tract.

CASE PRESENTATION

We report the case of a 34-year-old man with no significant medical history who presented persistent lower back pain but no hematuria, which is atypical for renal pathologies. Initial imaging identified a 30 × 14 mm enhancement mass in the right renal pelvis. Surgical intervention was performed through right nephroureterectomy, including excision of the bladder cuff. Histopathological examination confirmed the diagnosis of primary intestinal-type adenocarcinoma of the renal pelvis, characterized by necrotic carcinomatous proliferation with varying architectural patterns and occasional signet ring cells.

CLINICAL DISCUSSION

The diagnosis of primary renal pelvis adenocarcinoma is complicated by its nonspecific symptomatology and the potential for misdiagnosis as a more common urothelial carcinoma or a metastatic digestive-origin adenocarcinoma. Immunohistochemical staining supported a primary rather than metastatic digestive tract origin. This case underscores the need for a comprehensive diagnostic approach, including advanced imaging and meticulous histopathological analysis, to effectively differentiate this rare entity from other neoplasms.

CONCLUSIONS

This case highlights the diagnostic complexities and the critical need to be aware among clinicians about rare renal cancers such as primary adenocarcinoma of the renal pelvis. It also stresses the importance of interdisciplinary collaboration in the diagnosis and management of such rare cases, improving our understanding and requiring timely and accurate treatment.

Early diagnosis of renal pelvis villous adenoma: A case report

BACKGROUND

Villous adenoma is a rare tumor in the urinary system that usually occurs in the bladder. It is extremely uncommon in the renal pelvis. Most of the previously reported cases have been diagnosed with severe hydronephrosis associated with renal parenchyma atrophy prior to surgery. Because of its rarity, available information on the pathogenesis, diagnosis, treatment and prognosis of the disease is limited. We reported a case of kidney stones with hydronephrosis. During percutaneous nephroscopic lithotripsy, a renal pelvis tumor was found. Biopsy confirmed that the tumor was a villous adenoma of the renal pelvis.

CASE SUMMARY

A 68-year-old female was admitted to the hospital due to right kidney stones with right hydronephrosis. After admission, a urinary system plain computed tomography scan was performed, which revealed right kidney stones with right hydronephrosis and right upper ureteral dilatation. Multiple new cauliflower-like papillary masses were then discovered in the renal pelvis and calyces during right percutaneous nephroscopic lithotripsy. Biopsy results indicated villous adenoma with high-grade glandular intraepithelial neoplasia. The patient underwent laparoscopic radical resection of the right kidney and ureter. Based on histopathological and immunohistochemical examination, the patient was diagnosed with villous adenoma without adenocarcinoma.

CONCLUSION

Villous adenoma is rare in the urinary system. We reported a case of renal pelvis villous adenoma, which may provide useful information for the early diagnosis and treatment of this tumor.

Case report: A rare case of synchronous mucinous neoplasms of the renal pelvis and the appendix

Background

Mucinous neoplasms are tumors arising in the epithelial tissue, characterized by excessive mucin secretion. They mainly emerge in the digestive system and rarely in the urinary system. They also seldom develop in the renal pelvis and the appendix asynchronously or simultaneously. The concurrence of this disease in these two regions has not yet been reported. In this case report, we discuss the diagnosis and treatment of synchronous mucinous neoplasms of the right renal pelvis and the appendix. The mucinous neoplasm of the renal pelvis was preoperatively misdiagnosed as pyonephrosis caused by renal stones, and the patient underwent laparoscopic nephrectomy. Herein, we summarize our experience with this rare case in combination with related literature.

Case presentation

In this case, A 64-year-old female was admitted to our hospital with persistent pain in the right lower back for over a year. Computer tomography urography (CTU) showed that the patient was confirmed as right kidney stone with large hydronephrosis or pyonephrosis, and appendiceal mucinous neoplasm (AMN). Subsequently, the patient was transferred to the gastrointestinal surgery department. Simultaneously, electronic colonoscopy with biopsy suggested AMN. Open appendectomy plus abdominal exploration was performed after obtaining informed consent. Postoperative pathology indicated low-grade AMN (LAMN) and the incisal margin of the appendix was negative. The patient was re-admitted to the urology department, and underwent laparoscopic right nephrectomy because she was misdiagnosed with calculi and pyonephrosis of the right kidney according to the indistinctive clinical symptoms, standard examination of the gelatinous material, and imaging findings. Postoperative pathology suggested a high-grade mucinous neoplasm of the renal pelvis and mucin residing partly in the interstitium of the cyst walls. Good follow-up results were obtained for 14 months.

Conclusion

Synchronous mucinous neoplasms of the renal pelvis and the appendix are indeed uncommon and have not yet been reported. Primary renal mucinous adenocarcinoma is very rare, metastasis from other organs should be first considered, especially in patients with long-term chronic inflammation, hydronephrosis, pyonephrosis, and renal stones, otherwise, misdiagnosis and treatment delay may occur. Hence, for patients with rare diseases, strict adherence to treatment principles and close follow-up are necessary to achieve favorable outcomes.

Traditional Serrated Adenoma of the Urinary Bladder: The First Report

A 71-year-old woman was hospitalized with hematuria and underwent cystourethroscopy. Cystourethroscopy revealed a polypoid bladder tumor. Histopathologic examination showed complex villiform growth pattern, slit-like serrations, and ectopic crypts lined by epithelium with eosinophilic cytoplasm, pseudostratified elongated nuclei, consistent with traditional serrated adenoma. Nephrogenic and intestinal metaplasia with severe inflammation were present in adjacent bladder mucosa. Molecular study of the polyp revealed mutation (p.G12V) in codon 12 of exon 2 of the KRAS gene. Traditional serrated adenoma is a rare type of colonic serrated polyp, making up less than 1% of the colonic polyps with a predilection to distal colon. In the literature, there is no traditional serrated adenoma reported outside the gastrointestinal tract. Here in we report the first extra-gastrointestinal traditional serrated adenoma within the bladder and bladder diverticulum, arising from intestinal metaplasia. The present study reports an additional information on molecular background of this unusual bladder polyp.

Villous adenoma of the renal pelvis: a common entity at an uncommon location

Villous adenoma is uncommonly seen in the urogenital tract and is even more rarely seen in the upper urinary tract and renal pelvis. Like colorectal adenomas, these neoplasms can transform into adenocarcinoma. The preoperative diagnosis is challenging due to their frequent association with hydronephrosis. Herein, we present the case of a villous adenoma of the renal pelvis in a 62-year-old man presenting with recurrent urinary tract infection. The computed tomography scan showed marked hydronephrosis but no suspicious mass in the right kidney. A laparoscopic right nephrectomy was performed. Gross examination revealed a dilated renal pelvis with an irregular exophytic lesion in the renal pelvis’s upper surface. The histopathological examination showed slender, elongated villi with thin fibrovascular cores, consistent with villous adenoma morphology. Isolated villous adenomas have a favorable prognosis. However, the pathologist should undertake a search for an invasive component.

Villous Adenoma in Renal Pelvis With Manifestation of Percutaneous Fistula and Mucus Secretion

A 70-year-old man, complaining of percutaneous fistula with jelly-like yellow mucus in the right kidney for a month, was admitted to our department. From computed tomography, stones and severe hydronephrosis but no suspicious mass was found in right kidney. Nephrectomy of right kidney was performed and pathological examination revealed a villous adenoma in the renal pelvis with moderate to severe atypical hyperplasia of glandular epithelium. Primary villous adenoma in renal pelvis is rare and believed to be related to chronic irritation of stone and inflammation. Mostly nephrectomy was performed before diagnosis was made.

Primary adenocarcinoma of the renal pelvis, ureter and the urinary bladder: A case report and review of the literature

Primary adenocarcinoma is a rare type of urological neoplasm. The present study reports the case of a 55-year-old man with multifocal adenocarcinoma of the renal pelvis, ureter and urinary bladder that occurred in association with a large cystic calculus and perinephric abscess. The patient had suffered from gross hematuria for 2 years and right flank pain for 2 months. Following a series of investigations, a large cystic calculus with multiple tumors in the renal pelvis and ureter was identified. Multifocal tumors and a large calculus were located in the bladder using a cystoscope. The pathological report of 3 individual biopsies revealed a moderately differentiated tubular adenocarcinoma. Right nephrectomy, ureterectomy, radical cystectomy and left ureterocutaneostomy were performed. The pathological investigation revealed a moderately differentiated adenocarcinoma of the renal pelvis, ureter and urinary bladder. No additional treatment was administered and the patient remains alive at follow-up without disease recurrence or metastasis. Although uncommon, the development of a tumor is possible in patients that possess long-standing urolithiasis, particularly when accompanied by hydronephrosis or infection.

Intestinal metaplasia of the renal pelvis: A case report and literature review

Metaplastic changes in the renal pelvis are infrequent and may be malignant transformations to adenocarcinoma. The current study reports a case of intestinal metaplasia in the right renal pelvis, which was associated with staghorn calculi, in a 56-year-old female. The patient underwent a percutaneous nephrolithotomy. Immunohistochemical assessment of the mucosa of the renal pelvis revealed the positive expression of carcinoembryonic antigen, cytokeratin (CK)-7 and CK20, but negative expression for CK5/6 and vimentin. Furthermore, Ki67 expression was diffusely positive, while p53 was negative. Unlike other previously reported cases, the patient opted for active surveillance as opposed to radical nephrectomy, following the removal of the calculi. No evidence of progression was observed after three years of follow-up. Therefore, etiological treatment and close follow-up may be a suitable treatment option for localized intestinal metaplasia.