Metastatic malignant renal mass

Clinical History

A 33-year-old previously healthy man developed attacks of right flank pain for 1 month and back pain for 1 week. He had no past history of stone disease, urinary tract infection or surgical intervention.

Imaging Findings

The patient was managed with abdominal sonography as routine investigation in the outpatient clinic revealing large left renal mass. So the patient was requested for triphasic MSCT examination (64 Slice) of the abdomen for characterization of this lesion. This study revealed heterogeneously enhancing soft tissue mass with malignant appearance in the upper and middle zones of the left kidney. It was seen adherent to the pancreatic tail and spleen with possibility of invasion. Multiple hepatic focal lesions, hypo-dense at the pre-contrast phase with minimal enhancement both arterial and venous phases less than the hepatic parenchyma denoting that these lesions were metastatic. Post-contrast study of the chest revealed multiple lymphadenopathy including left infraclavicular, middle mediastinal, retrocrural and regional LNs. Using the bone window, there were multiple osteolytic lesions at multiple dorsal and lumber vertebral bodies, left iliac bone and left pubic bone.

Discussion

Most Renal cell carcinomas (RCC) are incidentally diagnosed at imaging; the number of cases diagnosed by using the classic triad of haematuria, flank pain, and a mass in the abdomen continues to decline [1]. The majority of the solid enhancing renal masses found at imaging tend to be RCC, with other benign entities such as oncocytomas and lipid-poor angiomyolipomas being less common [2].
RCC is known for its impressive metastatic potential and must be considered in the differential diagnosis of any metastatic tumour [3]. After the lung, bone is the second most common site of metastasis in patients with RCC, regardless of whether they underwent nephrectomy [4]. Osseous metastasis occurs in 20%–60% of patients with RCC [5].
Single- and multidetector Computed Tomography (CT) have helped refine the diagnostic work-up of renal masses by allowing image acquisition in various phases of renal enhancement after intravenous administration. The scanning protocol should include unenhanced CT followed by imaging during the corticomedullary and nephrographic phases of enhancement. The nephrographic phase is the most sensitive for tumoral detection, while the corticomedullary phase is essential for imaging the renal veins for possible tumoral extension and the parenchymal organs for potential metastases [6].
The diagnosis in this case is based on the post-operative histopathology.

Differential Diagnosis List

Final Diagnosis

Metastatic left malignant renal tumour

URL:	https://eurorad.org/case/10095
DOI:	10.1594/EURORAD/CASE.10095
ISSN:	1563-4086