Case Report Marker-Negative Pheochromocytoma Associated with Inferior Vena Cava Thrombosis S. Poudyal, M. Pradhan, S. Chapagain, B. R. Luitel, P. R. Chalise, U. K. Sharma, and P. R. Gyawali Department of Urology and Renal Transplant Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal Correspondence should be addressed to S. Poudyal; poudyal.sujeet@gmail.com Received 16 January 2017; Revised 28 April 2017; Accepted 23 May 2017; Published 15 June 2017 Academic Editor: Giorgio Carmignani Copyright © 2017 S. Poudyal et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Pheochromocytoma associated with inferior vena cava (IVC) thrombosis is very rare. A 27-year-old female presented with right fank pain and hypertensive urgency. Contrast-enhanced CT abdomen and gadolinium-contrast MRI abdomen revealed right adrenal mass suspicious of malignancy with invasion and compression to the right IVC wall along with IVC thrombus extending from the level of renal veins to the level of confuence with hepatic veins. Her routine laboratory investigations including 24-hour urine fractionated metanephrines, vanillylmandelic acid, and cortisol were normal. Right adrenalectomy with IVC thrombectomy was done. Perioperative period was uneventful. Histopathology of the mass turned out to be pheochromocytoma with thrombus revealing fbroadipose tissue with fbrin. Pheochromocytoma may present with IVC thrombus as well as normal serum and urinary markers. Tus, clinical suspicion is imperative in perioperative management of adrenal mass. 1. Introduction Pheochromocytoma is a rare tumor of the catecholamine- producing cells of the adrenal medulla. Prevalence of the disease may vary but approximately 1 to 2 per 100,000 individuals are diagnosed annually [1]. Te classic hallmark of the disease is the triad of headache, episodic sudden perspiration, and tachycardia [1]. Te disease is commonly diagnosed biochemically by plasma-free metanephrines or 24-hour urine fractionated metanephrines and localized by imaging modalities like contrast-enhanced CT, MRI, or metaiodobenzylguanidine (MIBG) scintigraphy [2–6]. Te sensitivity and specifcity of biochemical markers are still 95- 96% and 86–91%, respectively [7]. It is likely that biochemical marker-negative pheochromocytoma may be encountered in clinical practice, though large adrenal mass with negative serum marker and inferior vena cava (IVC) thrombus is usually an adrenocortical carcinoma [8, 9]. Pheochromocy- toma coexisting with IVC thrombus is very rare [10]. Hence, we report a marker-negative pheochromocytoma which was associated with IVC thrombosis. 2. Case Report A 27-year-old female presented with intermittent dull-aching right fank pain for one month. It was associated with frontal headache, sweating, and palpitation. She had history of nor- mal vaginal delivery 45 days back. She had no signifcant past medical and familial history. Blood pressure at presentation was 180/110 mmHg with pulse of 90 beats/min. Tere was mild tenderness in the right fank with no other signifcant fndings. USG abdomen revealed right adrenal mass. CECT abdomen and gadolinium-contrast MRI abdomen revealed 6 × 4 cm heterogeneously enhancing mass with delayed washout suggestive of right adrenal malignancy with invasion to right IVC wall leading to narrowing and presence of nonenhancing IVC thrombus extending from the level of renal veins to the level of confuence with hepatic veins (Fig- ure 1). Venous Doppler of both lower limbs and echocardio- graphy were unremarkable. Her routine laboratory investiga- tions including serum creatinine, electrolytes, liver function tests, adrenocorticotropic hormone, and cortisol level were normal. Similarly, 24-hour urine fractionated metanephrines, Hindawi Case Reports in Urology Volume 2017, Article ID 6270436, 4 pages https://doi.org/10.1155/2017/6270436