INCIDENTAL SOLE CONTRALATERAL PLEURAL METASTASIS FROM RENAL CELL CARCINOMA SEVEN YEARS POST NEPHRECTOMY

Abstract

TOPIC: Disorders of the Pleura TYPE: Medical Student/Resident Case Reports INTRODUCTION: Renal cell carcinoma (RCC) accounts for 3% of all adult male cancers, and half of them are incidental findings on imaging [1]. 18% of patients have synchronous metastasis at RCC diagnosis, and 85% have metachronous metastasis within five years after surgery. A better prognosis is seen with a metachronous metastasis occurring after a long disease-free interval [2] CASE PRESENTATION: A 68-year-old male presented to an outside emergency department with generalized weakness, fatigue, and loss of appetite for a week's duration with no respiratory complaints. He was a former smoker who quit 40 years back. He had significant asbestos exposure as a sandblaster and changing railroad brake shoes. His initial blood work revealed an acute kidney injury with a serum creatinine of 14.8 mg/dL with no leukocytosis. Computed tomography (CT) abdomen revealed an obstructive right ureteropelvic junction stone (1.4 x 1 cm) with moderate hydronephrosis. Chest x-ray and CT revealed multiple right pleural soft tissue masses (largest measuring 7.7 x 3.1 x 3.5 cm) with no effusion concerning for malignancy (Figure A). Past medical history was significant for left clear cell RCC grade 3/4 with no invasion (T1bNxMx) treated by left radical nephrectomy seven years ago. His obstruction was relieved by urological intervention. A nuclear positron emission tomography showed hypermetabolic right pleural masses and a right paratracheal lymph node (Figure B). A CT-guided biopsy returned positive for metastatic RCC (Figure C1-C2). His creatinine improved, and he was discharged with an oncology follow-up DISCUSSION: The risk of RCC metastasis via hematogenous or lymphatic spread increases if it is locally advanced (stage 3-4), higher nuclear grade, and clear cell histology [2]. The lung is the frequent site of metastasis (45%), and pleural lesions occur in 12% along with lung spread [3]. Isolated pleural spread without an effusion is rare. Dormant metastasis uses Batson's venous plexus draining into thoracic veins (bronchial and intercostal) and reaches the pleura rather than by lung parenchyma direct extension [2]. Most reported cases of solitary pleural spread are symptomatic with effusion. Our patient was asymptomatic with incidental contralateral pleural metastasis without pleural effusion seven years postresection with a rare combination of pleural and paratracheal lymph node spread. 5-15% of patients recur with a distant spread questioning the current five-year surveillance strategy [4] CONCLUSIONS: Metastatic RCC to the pleura is a rare finding. This diagnosis should be considered in patients with RCC history, even if the presentation is many years after initial diagnosis and treatment. Postnephrectomy, the surveillance should be based on an individual's RCC risk factors REFERENCE #1: Ohnishi H, Abe M, Hamada H, et al. Metastatic renal cell carcinoma presenting as multiple pleural tumours. Respirology. 2005;10(1):128-31 REFERENCE #2: Brufau BP, Cerqueda CS, Villalba LB, Izquierdo RS, González BM, Molina CN. Metastatic renal cell carcinoma: radiologic findings and assessment of response to targeted antiangiogenic therapy by using multidetector CT. Radiographics. 2013;33(6):1691-716 REFERENCE #3: Saitoh H. Distant metastasis of renal adenocarcinoma. Cancer. 1981;48(6):1487-91 DISCLOSURES: No relevant relationships by Mohammed Alnijoumi, source=Web Response No relevant relationships by Cliff Chen, source=Web Response No relevant relationships by Tarang Patel, source=Web Response No relevant relationships by SACHIN PATIL, source=Web Response