Renal cell carcinoma presenting as a huge simple renal cyst

Radiographic evolution of a simple renal cyst to clear cell renal cell carcinoma in three years

A 53-year-old female was referred for evaluation of a small right renal mass. She had an oncological history of adenocarcinoma of the cervix in 2015. Upon review of her imaging, her right posterior lower-pole lesion demonstrated malignant transformation from a 2.7-cm simple cyst in 2016, to development of a complex cyst with internal vascularity, and ultimately a 1.6 cm, right, lower-pole, exophytic, enhancing, posteriorly located solid renal mass concerning for renal cell carcinoma. The patient opted for surgical removal and underwent a right robotic-assisted laparoscopic partial nephrectomy. Pathology was consistent with a T1a clear cell renal cell carcinoma.

Renal cell carcinoma originating in the free wall of simple renal cyst: Two unusual case reports with literature review

RATIONALE

Simple renal cyst (SRC) is a benign disease. However, rarely renal cell carcinoma (RCC) may be raised at the wall of a preexisting SRC. We herein describe 2 unusual cases of RCC arising from the outer surface of the free wall of the renal cyst.

PATIENT CONCERNS

A 75-year-old female and a male were admitted to our department because of an asymptomatic renal cystic mass. Although the case history, preoperative imaging, and intraoperative examination of the cyst were carefully evaluated, no concerns were raised with respect to the underlying malignancy.

DIAGNOSIS

RCC of the clear cell type was diagnosed based on the histology and pathological examination.

INTERVENTIONS

With an initial diagnosis of SRC, the retroperitoneal laparoscopic de-roofing of the SRC was performed in both of the patients. When the diagnoses were confirmed 7 days postoperative, both of them were readmitted to our department for a radical nephroureterectomy.

OUTCOMES

The postoperative course was uneventful and the two patients did not undergo further chemotherapy. They are currently well and have no clinical or radiological signs of recurrence.

LESSONS

Such cases remind us that seemingly benign renal cysts may harbor underlying neoplasia. Further evaluation and periodical follow-up are also recommended on the management of those seemingly benign renal cysts.

Renal cell carcinoma presenting as a simple renal cyst: A case report

Cases of renal cell carcinoma (RCC) presenting as a simple cyst are extremely rare. We herein report the case of a patient with RCC diagnosed as a simple renal cyst preoperatively. A 39-year-old female patient presented with abdominal pain for 3 months. Ultrasonography and contrast-enhanced computed tomography revealed a simple cyst in the left kidney. The patient underwent laparoscopic decortication of the renal cyst. Biochemical analysis of the cystic fluid revealed unusually low levels of potassium, sodium, calcium and glucose, and the histological examination of the floor of the cyst indicated malignancy. Laparoscopic nephrectomy was performed 20 days later and the pathological examination confirmed the diagnosis of RCC of the clear cell type. At the 2-year follow-up, the patient remained well and recurrence-free on imaging. The aim of the present study was to emphasize the importance of recognizing that RCC may occur in what appears to be a simple renal cyst based on imaging results. Biochemical analysis of the cystic fluid may help identify the presence of malignancy.

Complicated variation of simple renal cyst usually means malignancy: results from a cohort study

BACKGROUND

Currently, simple renal cysts (SRCs) are not considered to warrant follow-up or specific treatment unless a patient presents symptomatically. By demonstrating malignant transformation of SRCs, we urge regular follow-up and timely surgical treatment in affected patients.

METHODS

From September 2002 to September 2010, we treated 31 cases of renal cell carcinoma derived from SRCs. Among these patients, in 14 cases a SRC was radiographically detected by computed tomography (CT) or magnetic resonance imaging (MRI) prior to operation, and malignant tumors were detected by pathological analysis following laparoscopic cyst decortication; 13 of these patients received supplementary radical nephrectomy within 2 months, whereas one patient chose to receive active surveillance. The other 17 patients exhibited SRCs and were monitored by ultrasound for over 6 months; surgical treatment was chosen if a complicated variation of SRCs was found during surveillance, detected by ultrasound, and confirmed by CT or MRI. Median follow-up was 60 months (30 to 126 months). All data analyzed were collected with informed consent, and the study was approved by the ethical committee of our institute.

RESULTS

Pathological studies confirmed early-stage clear-cell renal cell carcinoma in all of the cases, with Fuhrman grade I to III. In decortication-detected malignancies, supplementary radical nephrectomy exhibited residual tumor in 7 out of 13 cases; the patient who chose active surveillance remains free of recurrence for 78 months, and all other patients survived without disease at the last follow-up.

CONCLUSIONS

Renal cell carcinoma may be detected incidentally in SRCs, and more attention should be paid to complicated variations of SRCs during surveillance, owing to the extremely high probability of malignancy. This interesting but alarming phenomenon might urge regular follow-up and timely surgical treatment in affected patients.

Papillary renal cell cancer is strongly associated with simple renal cysts

INTRODUCTION

The purpose of this study was to evaluate the prevalence of simple renal cysts (SRCs) in patients with renal neoplasia.

PATIENTS AND METHODS

The study population consisted of 482 patients who underwent partial or radical nephrectomy for kidney tumour between 2006 and 2010. Prevalence of cysts was evaluated retrospectively on a preoperative CT or MRI scan.

RESULTS

SRCs are more prevalent in patients with papillary renal cell cancer (RCC) than patients with clear cell RCC. All obese (BMI ≥30) patients in our study population had SRCs.

CONCLUSIONS

This is the first study to show an association between SRCs and papillary RCC.

Unexpected outcome after sclerotherapy of simple renal cyst

Background

Simple renal cysts usually have benign clinical features. We report a rare case of papillary renal cell carcinoma (RCC) associated with a large recurrent simple cyst following sclerotherapy.

Case Presentation

A 47-year-old Japanese woman received minocycline sclerotherapy for a large (9 cm in diameter) simple left renal cyst in May 2005. The cyst regrew, and second-line sclerotherapy with ethanol was performed in November 2005. Three years later, she developed papillary RCC on the wall of the recurrent renal cyst. Radical nephrectomy was performed, but the patient died of metastatic disease 15 months after surgery.

Conclusion

Malignant transformation from recurrent simple renal cyst to RCC may occur in the years following sclerotherapy, underscoring the need for long-term follow-up.

Characterization of N-diethylnitrosamine-initiated and ferric nitrilotriacetate-promoted renal cell carcinoma experimental model and effect of a tamarind seed extract against acute nephrotoxicity and carcinogenesis

Renal cell carcinoma (RCC), the commonest malignancy in adult kidney, lacks of early signs, resulting often in metastasis at first diagnosis. N-Diethylnitrosamine (DEN)-initiated and ferric nitrilotriacetate (FeNTA)-promoted RCC may be a useful experimental model, but it is not well characterized. In this study, histological alterations and oxidative stress markers were analyzed at different times throughout RCC development, histological subtype was re-evaluated in the light of current classification, and a tamarind seed extract (TSE) effect was examined. Male Wistar rats experimental groups were control, TSE, DEN, DEN+FeNTA, and TSE+DEN+FeNTA. TSE was given 2 weeks before DEN administration (200 mg/kg) and throughout the experiment. Fourteen days after DEN treatment, two FeNTA doses (9 mg Fe/kg) for acute nephrotoxicity study, and increasing FeNTA doses (3-9 mg Fe/kg) twice a week for 16 weeks for carcinogenesis protocol, were administered. In acute study, necrosis and renal failure were observed and TSE ameliorated them. Throughout carcinogenesis protocol, preneoplastic lesions were observed since 1 month of FeNTA treatment, which were more evident at 2 months, when also renal cysts and RCC were already detected. RCC tumors were obtained without changes in renal function, and clear cell histological subtype was identified in all cases. 4-Hydroxy-2-nonenal and 3-nitro-L: -tyrosine levels increased progressively throughout protocol. TSE decreased both oxidative stress markers and, although there was no statistical difference, it delayed RCC progress and decreased its incidence (21 %). This study brings an insight of the time course events in this carcinogenesis model, identifies clear cell subtype and establishes TSE renoprotective effects.