Bilateral sporadic synchronous clear cell renal cell carcinoma

Case contributed by Ammar Ashraf
Diagnosis certain


Anterior abdominal wall hernia. Plain CT abdomen to see its contents.

Patient Data

Age: 65 years
Gender: Female

Omental fat-containing supraumbilical anterior abdominal wall hernia. No bowel herniation is seen. A hypodense lesion (average density=18 HU) measuring 1.9 x 1.8 cm is seen at the upper pole of right kidney. A tiny speck of calcification is noted in it. 
Impression: Right renal hypodense lesion with a tiny speck of calcification; complex Bosniak cyst?  For further evaluation with contrast enhanced CT or renal ultrasound.

A well-defined mildly hypoechoic lesion measuring 2.4 x 2.8 cm, having a tiny mural calcification, is seen at the upper pole of the right kidney. Left kidney is normal.

An enhancing lesion measuring 2.5 x 2.9 cm is seen at the upper/mid pole of the right kidney. Renal vessels and IVC are patent and well opacified. Two tiny simple cortical cysts are noted along the lower pole of right kidney. No suspicious focal lesion is seen in left kidney. No local or distant metastases are seen.

Impression: Enhancing right renal mass lesion, suspicious of a malignant lesion like renal cell carcinoma (RCC).

7 months later


Previously noted mass lesion in right kidney had been surgically removed. A well defined mildly hypoechoic suspicious lesion measuring 2.4 x 2.4 cm, is now seen at the upper pole of the left kidney; this lesion was not seen on the previous ultrasound examination. 

13 months later


An interval increase is seen in the size of the left renal lesion which now measures 3.9 x 4.2 cm, as compared to the previous measurement of 2.4 x 2.4 cm.

A heterogeneously enhancing mass lesion, measuring 4.2 x 4.1 cm is seen at the upper pole of the left kidney (the left kidney was reported normal on the previous CT scan; however, retrospectively, there was a lesion at its upper pole which has now progressed in size). Renal vessels and IVC are patent and well opacified. Post-surgical changes are noted at the upper pole of the right kidney; however, no suspicious lesion is seen in the right kidney. Mildly hyperdense sludge and a few tiny radiopaque calculi are noted in the gallbladder.

Impression: Heterogeneously enhancing left renal mass lesion, suspicious of renal cell carcinoma. 

  • Procedure: Laparoscopic right partial nephrectomy. Diagnosis: Histologic type: Clear cell renal cell carcinoma. Histologic grade (Fuhrman nuclear grade): Grade 2. Tumor size: 2.5 x 1.5 x 1.0 cm. Tumor focality: Unifocal. Macroscopic extent of tumor: Tumor limited to kidney. Microscopic tumor extension: Tumor limited to kidney. Margins: Involved by invasive carcinoma: Renal parenchymal margins (partial nephrectomy only). Sarcomatoid features, tumor necrosis and lymphovascular invasion: Not identified. Pathologic staging: pT1a pNx pMx. Immunohistochemical stains showed that the carcinoma cells are immunoreactive to vimentin, CD10 and E-Cadherin. There is no immunoreactivity to CD117 (C-Kit) and cytokeratin 7. Colloidal iron special stain was essentially negative. This immunohistochemical pattern confirms the diagnosis of conventional type, renal cell carcinoma, clear cell type.
  • Procedure: Left partial nephrectomy. Diagnosis: Histologic type: Clear cell renal cell carcinoma. Grade: Grade 2. Tumor size: 3.5 x 3.5 x 3.5 cm. Tumor focality: Unifocal. Anatomic extent of tumor: Tumor extension into perinephric tissue (beyond renal capsule). Margins: Uninvolved by invasive carcinoma. Sarcomatoid features: 5%. Tumor necrosis: 15%. Lymphovascular invasion: Not identified. Regional lymph nodes (two): Negative for malignancy. Pathologic staging:  pT3a pN0 pMx. 

Case Discussion

​Bilateral renal cell carcinoma (RCC), is a rare clinical condition having a reported incidence of 0.4-5% 1. It may be synchronous (coexisting at the time of initial diagnosis) or metachronous (developing subsequently) 1. The risk of developing subsequent contralateral RCC (metachronous) is roughly 10 times higher after the initial detection of RCC. Black race, male gender, younger age, and papillary histopathology are the peculiar predisposing factors for a metachronous contralateral RCC 1. The risk of metachronous RCC is also higher in the patients with positive family history of RCC or patients with history of Von Hippel-Lindau disease 1. Some authors use 6 months cutoff to define metachronous disease whereas others use one year 1. In our case, the time interval between the detection of right and left renal lesions was 7 months. 

After the first postoperative ultrasound examination, the patient missed her regular follow-up visits and returned to the clinic after 6 months when 2nd postoperative ultrasound, followed by the contrast enhanced CT scan were performed. Later on, the patient underwent left partial nephrectomy. 

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