Uncommon site of metastasis from renal cell carcinoma: Case report

BACKGROUND: Renal cell carcinomas (CCR) account for 90% of renal tumors. Presence of latent distant metastasis is characteristic of RCC and may manifest more than a decade after nephrectomy. Gallbladder (GB) is a rare site of metastasis, with few reports in the literature. A case of metastasis from RCC to GB nine years after initial diagnosis is reported herein. CASE REPORT: Male patient, 74 years, nine years post right radical nephrectomy for grade 2 clear-cell adenocarcinoma, T3BN0M0. During onset, Magnetic Resonance Imaging (MRI) evidenced T2-weighted hypointense and T1-weighted hyperintense lesion, with early and persistente contrast enhancement and exophytic bulging of the underlying outer vesicular margin. T1-weighted hypointense and T2-weighted slightly hyperintense nodular formation was also evidenced in the body portion of the pancreas, with 1.5 × 1.2 cm. The patient was subjected to videolaparoscopic cholecystectomy associated to endoscopic ultrasound (EUS) intraoperatively for investigation of the pancreatic nodule. The anatomopathological examination of the gallbladder was compatible with infiltrating metastasis from clear-cell carcinoma of primary renal site. A solid, hypoechoic, oval nodule with 14 mm was found at EUS, which cytology was suggestive of clear-cell Carcinoma. Because this is an indolent disease with oligometastasis, local ablative treatment with fractionated stereotactic radiation therapy with a dose of 40 Gy was selected. The patient is found with stable disease one year after radiation therapy. CONCLUSION: Gallbladder is an unusual site of RCC metastasis. In patients with history of this disease, all vesicular lesions should be given attention, even where the primary tumor has been treated many years before.