Imaging studies frequently provide information above and beyond what is expected at the time of requisition. Unexpected diseases may be discovered prior to the development of symptoms and thus provide the opportunity for early diagnosis and intervention. Early treatment can often prevent or limit complications, including major morbidity and death. Koeneman et al. reported the prevalence of malignant renal tumors to be 0.2% in adults aged 50–79 years. [1] In many cases these tumors are discovered incidentally on imaging, usually by abdominal computed tomography (CT) scan or ultrasound scan. [2] The identification of a renal malignancy on routine echocardiography is exceedingly rare. Here we present a case where a large malignant neoplasm originating from the right kidney was first identified as an incidental mass in the inferior vena cava on echocardiogram.

A 73-year-old female met with her cardiologist for a routine check-up. She was in her usual state of health; she denied dyspnea, chest pain, palpitations, syncope pre-syncope, shortness of breath, dysuria, and abdominal pain. All other review of systems was unremarkable. A new murmur was noted on physical examination, therefore a two-dimensional resting echocardiogram was done which revealed a mass in the inferior vena cava (IVC), two centimetres below the right atrium (Figure 1). The patient was admitted to the hospital for further evaluation. On admission her vital signs were: temperature - 36.4°C, respiratory rate - 20/min, pulse - 68/min, blood pressure - 134/69 mmHg, and BMI 40 Kg/m². Cardiac examination revealed a grade 2/6 crescendo-decrescendo murmur heard at the base that did not radiate, there were no gallops and point of maximal impulse was not displaced. The remainder of the physical exam was unremarkable. Laboratory analysis revealed hemoglobin of 10.8 g/dL and glomerular filtration rate of 42 mL/min. Rest of the laboratory investigations of CBC, electrolyte panel, urinalysis, thyroid function, and coagulation studies were within normal range. A CT scan of the chest and abdomen revealed a 10x13x15 cm mass arising from the anterior right kidney with direct extension into the suprarenal IVC (Figure 2). There was no evidence of distant metastasis. Pulmonary emboli (PE) were also noted in the right main pulmonary artery and right middle arteries. Intravenous heparin therapy was initiated. After one month of anticoagulation, repeat CT scan demonstrated no interval change of the mass. Three months after presentation, the patient underwent right nephrectomy with excision of a 12.5x11.5x10.5 cm mass which was confirmed to be renal cell carcinoma (RCC) with extensive necrosis and hemorrhage. Vascular and cardiothoracic surgeons assisted in the resection of the 14.5 cm long, 1.2 cm diameter, polypoid portion that extended into the IVC and was adherent to the inner lining of the vein. The IVC was cross clamped, opened, and the mass was resected. The IVC was then flushed, the incision was closed, air removed, and the clamps released with restoration of blood flow. The patient is well and is on regular follow-up.

The differential diagnosis for an IVC mass includes: bland thrombus (most common), malignant thrombus, carcinoma (renal cell, hepatocellular, and adrenocortical), renal angiomyolipoma, pheochromocytoma, pseudolipoma, and primary intraluminal sarcoma. [3] A malignant etiology should be considered in all patients with a new IVC mass.

Renal cell carcinoma is associated with extension into the IVC in 4–10% of cases, [4] [5] [6] with approximately 1% extending to the level of the right atrium. [5] Up to 6% patients with direct extension into the IVC suffer pulmonary embolism which is a poor prognostic sign and is associated with a high rate of mortality. [5]

Patients with RCC may present with microscopic hematuria, complaints of flank or abdominal pain and weight loss. [4] If a pulmonary embolism (PE) has occurred symptoms, typical of PE may present including dyspnea, pleuritic chest pain, hypotension, hemoptysis, and hypoxemia. [7] Dyspnea on exertion and syncope may present if the tumor extends to the level of the right atrium. [8] Serious complications of RCC with IVC and right atrium infiltration include massive PE, tricuspid valve obstruction, and Budd-Chiari syndrome. [4] This patient did not experience any of these associated symptoms.

Surgical intervention for RCC with IVC extension is the standard of care as complete surgical resection can potentially be curative. [4] Additionally, surgical intervention is required to prevent serious complications such as massive PE, tricuspid valve obstruction, and Budd-Chiari syndrome with resultant hepatic failure. [4] Operative technique is determined by the level of tumor extension following the Neves classification system (Table 1) [6]. The patient was Neves Level IV, thus warranting a multidisciplinary surgical approach including urological and cardiothoracic surgical evaluation. If the tumor had invaded the right atrium, cardiopulmonary bypass would have been recommended. [6]

This case is a unique example of an asymptomatic individual diagnosed with an advanced malignancy based on an echocardiographic abnormality and thus underscores the importance of careful and detailed review of all radiology investigations. The serendipitous discovery of this nephrogenic malignancy allowed for the initiation of potentially curative treatment before the development of serious complications including massive PE, tricuspid valve obstruction, and death.

1. Koeneman KS, Cote WL, Martin DJ, Littooy FN, Flanigan RC. Renal screening ultrasound in an older population with pathologic correlation [Abstract no. 1276]. Presented at the American Urological Association 92nd annual meeting. New Orleans, Louisiana, April 12-17, 1997. J Urol 1997;157:327.   [Pubmed]    
2. Higgins JC, Fitzgerald JM. Evaluation of incidental renal and adrenal masses. Am Family Physician 2001;63(2):288–94, 299.   [Pubmed]    
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4. Zini L, Haulon S, Decoene C, et al. Renal cell carcinoma associated with tumor thrombus in the inferior vena cava: surgical strategies. Ann Vasc Surg 2005;19(4):522–8.   [CrossRef]   [Pubmed]    
5. Woodruff DY, Van Veldhuizen P, Muehlebach G, Johnson P, Williamson T, Holzbeierlein JM. The perioperative management of an inferior vena caval tumor thrombus in patients with renal cell carcinoma. Urol Oncol 2011 Apr 20.   [CrossRef]   [Pubmed]    
6. Radak D, Milojevic P, Babic S, et al. Renal tumor with tumor thrombus in inferior vena cava and right atrium: the report of five cases with long-term follow-up. Int Urol Nephrol 2011;43(4):1033–8.   [CrossRef]   [Pubmed]    
7. Shimada S, Saito H, Arai Y. Pulmonary embolism caused by spontaneous migration of tumor thrombus of renal cell carcinoma: A report of two cases. Int J Urol 2012 Mar;19(3):277–8.   [CrossRef]   [Pubmed]    
8. Swan RZ, Hanna EM, Sindram D, Iannitti DA, Martinie JB. Adrenocortical Carcinoma with Intracaval Extension to the Right Atrium: Resection on Cardiopulmonary Bypass. Ann Surg Oncol 2012;19(4):1275.   [CrossRef]   [Pubmed]