Mucinous cystadenoma of a horseshoe kidney: A case report and literature review

Primary mucinous tumors of the renal pelvis: Clinical, histopathological, and molecular analysis of three cases

Primary mucinous tumors of the renal pelvis are extremely rare and pose challenges in terms of diagnosis and treatment. This study reviewed the clinical and pathological characteristics of mucinous tumors of the renal pelvis, including mucinous cystadenocarcinomas and mucinous cystadenomas. Immunohistochemical analysis was conducted in three cases, along with KRAS gene detection using the Amplification Refractory Mutation System (ARMS) method. The results revealed mucinous epithelium with acellular mucinous pools in all cases, and acellular mucinous pools were observed in the renal parenchyma and perirenal fat capsules. All tumors expressed CK20 and CDX2, and one case showed KRAS gene mutation. The study suggests that mucinous cystadenomas of the renal pelvis may exhibit borderline biological behaviors. This study is the first to report a KRAS gene mutation in a mucinous cystadenoma of the renal pelvis, offering valuable insights into the diagnosis and treatment of this rare condition.

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.

Nephron-sparing surgery for primary mucinous adenocarcinoma of renal pelvis in horseshoe kidney: A case report

RATIONALE

Mucinous adenocarcinoma of the renal pelvis is extremely rare in malignancy of the renal pelvis, and <100 cases have been reported so far. However, horseshoe kidneys appear to be more prone to this mucinous gland metaplasia. Due to the lack of a specific diagnostic basis, it is difficult to confirm the diagnosis before surgery, which is easy to cause misdiagnosis.

PATIENT CONCERNS

We report a 64-year-old male patient who found a cystic mass in the left kidney during physical examination. CT examination showed a horseshoe kidney with a cystic mass 9.5 × 8.0 cm in front of the left kidney, lacking obvious diagnostic features.

DIAGNOSIS

It was misdiagnosed as cystic teratoma before the operation, and was diagnosed as mucinous adenocarcinoma of the renal pelvis through pathological examination after the operation.

INTERVENTIONS

Resection of the tumor by nephron-sparing surgery and postoperative chemotherapy.

OUTCOMES

No tumor recurrence was found at 6 years of follow-up. After 7 years, the patient had multiple metastases in the abdominal wall and peritoneum, and no tumor recurrence was found in the urinary system. The patient received chemotherapy again and survived well.

LESSONS

The prognosis of nephron-sparing tumor resection for MRAP is not significantly different from that of radical nephroureterectomy + bladder cuff excision. Because it can reduce the risk that patients can not tolerate follow-up chemotherapy due to abnormal renal function after surgery, which may be more beneficial in patients with kidney abnormalities or chronic disease.

Mucinous cystadenoma of the renal parenchyma presenting as a Bosniak IIF complex renal cyst

Introduction

A primary retroperitoneal mucinous cystadenoma should be surgically resected because of the risk of malignant transformation. However, mucinous cystadenoma of the renal parenchyma is very rare, and preoperative imaging mimics complicated renal cysts.

Case presentation

A 72-year-old woman presented with a right renal mass on computed tomography that was followed up as a Bosniak IIF complicated renal cyst. One year later, the right renal mass gradually increased in size. Abdominal computed tomography showed an 11 × 10 cm mass in the right kidney. A laparoscopic right nephrectomy was performed because cystic carcinoma of the kidney was suspected. Pathologically, the tumor was diagnosed as mucinous cystadenoma of the renal parenchyma. Eighteen months after resection, the disease has not recurred.

Conclusion

Here, we experienced a case of a renal mucinous cystadenoma as a slowly enlarging Bosniak IIF complex renal cyst.

Surgery for Cystadenoma of the Retromolar Pad Area With Reconstruction Using a Buccal Fat Pad Flap: A Case Report

Salivary gland tumors can also occur rarely in the retromolar area, though common near the junction of hard and soft palate, labial mucosa, and buccal mucosa. Most salivary gland tumors in the retromolar pad area are malignant and should be excised. The cystadenoma is a rare, benign, salivary gland tumor. Importantly, incomplete resection of this tumor can lead to recurrence or cervical lymph node metastasis. We reported herein a case of cystadenoma arising in the right retromolar pad area in a 63-year-old male patient who underwent reconstruction using a buccal fat pad flap (BFPF) after the surgical removal of the tumor with a 10-mm margin left a defect with bone exposure. No evidence of recurrence or complication was found at the postoperative, three-year follow-up.

Papillary mucinous cystadenoma of the kidney: Case report and review of literature

Epithelial tumors that originate from the kidney are uncommon. The majority of cases reported in the literature are malignant, with <1% of adenocarcinomas. Adenomas are even rarer. A case of mucinous cystadenoma of the kidney was diagnosed and treated in Cangzhou Hospital of Integrated TCM-WM•HEBEI. The clinical feature of this disease was atypical. The principal symptom of mucinous cystadenoma of the kidney was a lump in the upper abdomen with intermittent pain in the abdomen. The tumor size ranged from 5-12 cm. The patient was clinically diagnosed with multiple renal cysts with thickened walls and hemorrhage. The patient was admitted to the hospital five days later, and a left nephrectomy was performed. The tumor capsule was integrated and did not adhere to the adjacent tissue. One or multiple smooth-walled dilated cystic areas were found on the cut section, some of which were filled with grey opaque gelatinous clots. Under light microscopy, the epithelial lining was characterized by a single layer of columnar with papillary proliferation and almost had no mitosis. Immunohistochemistry showed that the cyst was positive for carcinoembryonic antigen (CEA) and proliferating cell nuclear antigen (PCNA). Following nephrectomy, the patient was followed up for 8 years and no recurrence and metastasis were found. A total of five articles were retrieved, including six cases with mucinous cystadenoma of the kidney. The clinical feature of this disease was atypical, making clinical diagnosis difficult. Histopathological examination revealed that the cyst consisted of mucinous epithelium with supporting fibrous tissue and immunohistochemistry showed that the cyst was positive for CEA and PCNA. Patients with all resection of the affected kidney had an improved prognosis.

Parenchymal mucinous cystadenoma of the kidney: a case report and literature review

Background

Mucinous cystadenoma (MC) of the kidney is exceedingly rare. We found 22 similar cases in the literature. These masses are underdiagnosed due to radiologic similarities with simple renal cysts.

Case presentation

A 66-year-old man with a previous history of hypertension and anxiety was referred to our tertiary clinic with left flank pain. Ultrasound revealed a 60 mm-sized, complex cystic mass with irregular septa in the lower pole of the left kidney (different from last year's sonographic findings of a simple benign cyst with delicate septa). CT scan showed the same results plus calcification. Due to suspected renal cell carcinoma, a radical nephrectomy was performed. Postoperative histopathologic examination revealed a cyst lined by a single layer of columnar mucin-producing cells with small foci of pseudo-stratification, consistent with the MC’s diagnosis. The first follow-up visit showed normal blood pressure without medication and no flank pain and anxiety after a month.

Conclusion

It is quite challenging to distinguish the primary MC of the kidney from a simple renal cyst based on clinical and imaging findings. The radiologic features of these entities overlap significantly. Thus, complex renal cyst and renal cysts with mural nodules should be followed closely to detect malignancy earlier.

Mucinous cystadenoma with calcification arising from renal pelvis radiologically resembled renal calculus with hydronephrosis: report of a rare case and review of the literature

Primary mucinous cystic tumors occurring in the renal pelvis or the entire pyelocaliceal system are uncommon. Most are mucinous cystadenomas and less frequently mucinous cystadenocarcinomas. In fact, the publications on these neoplasms are limited to a few cases. Because mucinous cystadenomas of kidney are exceedingly rare, little is known about their natural history, pathogenesis and clinicopathologic features. Herein, we describe 1 case of mucinous cystadenoma arising from the renal pelvis with calcification, which resembled hydronephrosis with renal calculus radiologically. The patient presented with a history of intermittent dull pain on the right waist since 10 years ago. He had no history of removing urinary calculus or long-standing chronic infection in urinary system. The histopathology was unique since the inner surface of the cyst was covered by a mucinous epithelium connected to a urothelium, a transition from nonneoplastic urothelium to mucinous epithelium was demonstrated by immunohistochemical staining for GATA-binding protein 3 (GATA3). This suggests that mucinous cystadenoma of renal pelvis, like its malignant counterpart, maybe arises in foci of metaplastic mucinous areas.

Mucinous Cystadenocarcinoma in a Horse Shoe Kidney Masquerading as Giant Hydronephrosis - A Case Report: Diagnostic Challenges, Lessons Learnt and Review of Literature

Primary epithelial tumour of the renal pelvis is a rare entity. So far, very few cases are reported in literature. Of these, mucin secreting adenocarcinomas are distinctly rare. However, mucinous cystadenocarcinoma, that too arising in a horse shoe kidney is extremely rare to be reported. Mucinous cystadenomas and carcinomas arising from the renal pelvis are regarded to be secondary to a metaplastic change in the urothelium. Here, we present a case of a 51-year-old male, who complained of abdominal pain, palpable abdominal mass, haematuria along with passage of mucoid material in the urine, with a very poorly functioning kidney. A pre-operative diagnosis of horse shoe kidney with pelvi ureteric junction obstruction and a poorly functioning kidney was made. Intraoperative findings and frozen section biopsy were suggestive of mucin secreting cystic mass and a right heminephrectomy was done. The final histopathology was suggestive of mucinous cystadenocarcinoma of the renal pelvis of the right moiety. This case is presented for its rarity, diagnostic challenges faced and the lessons learnt, stressing on the need for having a high index of clinical suspicion in making such diagnosis.