Synchronous renal and colonic carcinomas

Case contributed by Ammar Ashraf
Diagnosis certain


History of abdominal pain and constipation for 2 months. Presented to the emergency department with worsening pain & constipation associated with vomiting for two days.

Patient Data

Age: 65 years
Gender: Male

Findings: Dilated large bowel loops with a few air fluid levels are seen. No significant air is seen in the rectum. No pneumoperitoneum is seen. A sizable partly calcified lesion is seen along the lower pole of the left kidney.

Impression: Dilated large bowel loops with a few air fluid levels, likely due to distal large bowel obstruction. Large calcified lesion along the lower pole of the left kidney; possible differential includes malignancy (RCC), hydatid cyst or calcified renal abscess (tuberculous). 

A well-defined exophytic lesion measuring 3.5 x 4.0 cm (having an average density of 26, 35, 43 HU on plain, arterial & venous phases respectively) is seen at the upper pole of the left kidney.

An exophytic lesion containing multiple calcifications is seen at the lower pole of the left kidney; this lesion measures approximately 6 x 7 cm and has an average density of 39, 41, 48 HU on plain, arterial & venous phases respectively. A sub-centimeter exophytic hyperdense renal cyst (average density=65HU) is seen at the lower pole of the left kidney. Multiple simple renal cysts are also seen in the left kidney; the largest cyst seen at the mid pole measures 12 x 13 cm. Renal vessels and IVC are patent. No significant para-aortic lymphadenopathy is seen.

Segmental mural thickening in the descending colon, associated with dilatation of the proximal colon. Mild pericolic fat stranding and a few small lymph nodes are also seen along the thickened colonic segment.

A small fat density lesion (average density=-9 HU) is seen in the left adrenal gland which is likely an adrenal adenoma.

A few osseous hemangiomas (polka dot sign) are seen in the lumbar spine.


  • suspicious exophytic lesions at the upper and lower poles of the left kidney; possibility of renal malignancy (like papillary renal cell carcinoma) needs to be considered
  • segmental thickening of the descending colon with proximal colonic dilatation, highly suspicious of colonic carcinoma

Next day


Complementary CT with positive rectal contrast: Constricting soft tissue mass lesion with circumferential luminal narrowing and a nodular tumor surface (apple core sign/napkin ring sign) is seen in the descending colon. Mild fat stranding and a few small loco-regional lymph nodes are seen in the surrounding pericolic fat.  Mild mural thickening (6 mm) of the splenic flexure is also noted; nature ? Marked dilatation of the cecum and ascending colon reaching up to 11.5 mm in diameter is seen. Multiple diverticula are seen in the descending colon.

Procedure: Left hemicolectomy with primary anastomosis and left radical nephrectomy. 

  1. Left hemicolectomy: Moderately differentiated mucin secreting adenocarcinoma (mucinous component less than 50%). The tumor has penetrated the muscle coats and has invaded pericolic fat. No evidence of peritumoral lymphovascular space invasion is identified. Both proximal and distal resection margins clear. Tumor is seen 1.4 mm from radial margin. Serosal surface appears clear. All lymph nodes are free of tumor (0 of 9 lymph nodes). Maximum tumor size 4.5 cm (gross). Negative for large vessel invasion. pTNM classification; pT3, pN0, pMx.
  2. Left radical nephrectomy: Both upper pole and lower pole lesions show papillary renal cell carcinoma. Necrosis, cystic degeneration, calcification and ossification noted. Fuhrman nuclear grade= G2. Lower pole tumor size 7.0 cm maximum dimension (gross). Upper pole tumor size 3.0 cm maximum dimension (gross). Tumor is seen very close to renal capsule but does not invade the perirenal fat. Both vascular and ureteric resection margins clear. Pelvis and pelvic fat not invaded by tumor. Adrenal gland grossly and microscopically free of tumor. Negative for lymphovascular space invasion. Two lymph nodes identified from hilar region are free of metastatic tumor.
  3. Para-aortic lymph node specimen: Twelve (12) lymph nodes histologically identified in the material submitted. None show any evidence of metastatic tumor. Pathological staging pTMN: pT2, pN0, pMx. Comments: The two renal cystic lesions essentially show a similar tumor comprising papillary renal cell carcinoma with both showing clear cells lining the fibrovascular stroma and including large numbers of foamy histiocytes. In the smaller lesion, the papillae are lined by plumper cells with eosinophilic cytoplasm, but in some areas smaller clear cells are also identified. There is extensive necrosis of tumor and in some areas the cyst lining lacks the neoplastic cell lining. The lower pole lesion shows extensive calcification and ossification but many areas of viable tumor with the characteristic features of papillary renal cell carcinoma are seen.

Case Discussion

Renal cell carcinoma (RCC) is the commonest malignant renal neoplasm. It is associated with multiple other primary neoplasms, like bladder, prostate, breast, colon, lung and non-Hodgkin lymphoma (NHL) which is a well-known factor; however, its concurrent detection with a gastrointestinal neoplasm is unusual but well acknowledged entity 1. The prevalence of synchronous RCC and colonic malignancy is variable and its reported incidence in the literature usually varies between 0.03-0.5% 1. The exact etiopathogenesis of these synchronous malignancies is not yet fully explained. It is postulated that synchronous malignancies affect the tissues having identical embryological roots 1. Multiple synchronous malignancies occur when these tissues are exposed to certain carcinogens or environmental risk factors (alcohol, tobacco, ultraviolet light, pollution, hormonal factors, chemotherapy, & radiation exposure) 1.

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