Renal cell carcinoma and multiple angiomyolipomas in a patient with tuberous sclerosis

Skull x-rays showed a nodular calcification in the temporal region, and computed tomography (CT) brain scans showed bilateral subependymal hamartomas with calcification and a subependymal right cell astrocytoma in the frontal horn of the right lateral ventricle that caused hydrocephalus.

Contrast enhanced computed tomography (CECT) and superselective digital subtraction angiography were performed, followed by embolizsation, segmental nephrectomy and biopsy.

CECT revealed a large enhancing mass in the inferior pole of the right kidney and multiple small hypodense lesions in both kidneys. The hypodense lesions were considered to be angiomyolipomas because of their characteristic density (fat density).

CT-guided fine-needle aspiration (FNA) was contraindicated because of the high risk of haemorrhage.

Selective digital subtraction angiography of the right renal artery, showed a hypervascular mass. Embolisation of the main feeding artery (the anterior branch of the renal artery) with metallic coils was performed, followed by segmental nephrectomy.

Histological examination confirmed the coexistence of a poorly differentiated renal cell carcinoma (grade IV), with a prognostic rate of 17 on the colimbou scale, and multiple angiomyolipomas.

Patients present with seizures, mental retardation, adenoma sebaceum and hamartomas. The last, which is the characteristic lesion of the disease, may involve many organs including the brain, skin, kidneys, eyes, lungs, heart and bones.

Angiomyolipomas are benign tumours of the kidney and frequently involve patients with TSC (40-80%). Even though they usually show no symptoms, they may sometimes cause flank pain or haematuria.

Angiomyolipomas are vascular lesions and have a tendency to bleed. They can be locally invasive and demonstrate tumour-like neovascularity on angiography.

Although it has been suggested that TSC genes are involved in the pathogenesis of RCC, the coexistence of angiomyolipomas and RCC is quire rare. However, the differential diagnosis of a renal vascular mass in a patient with TSC and angiomyolipomas should always include RCC so that proper diagnostic procedures are followed.