MEDIASTINAL LYMPHADENOPATHY AS METASTATIC MANIFESTATION OF RENAL CELL CARCINOMA

Abstract

SESSION TITLE: Fellows Lung Cancer Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Renal cell carcinoma (RCC) is one of the common malignancies diagnosed in United States.(1) Since early 1990s, its incidence has risen and thought to be attributed to the increased prevalence of risk factors such as smoking, obesity and hypertension.(2) With the advent and frequent utilization of imaging such as ultrasonography and computed tomography (CT), mortality related to RCC has declined.(1) Lung is a common site for metastatic dissemination due to invasiveness of RCC into nearby vascular structures. We present an unusual case of RCC with lymphatic metastasis to lungs, contrary to the known mechanism of vascular metastasis. CASE PRESENTATION: 57-year-old female, current smoker of 25 pack years, presents to the hospital with complaints of recurrent painful hematuria after failing outpatient management for presumed nephrolithiasis. CT abdomen showed a 9.7 cm mass in superior pole of left kidney with involvement of the adjacent adrenal gland. A subsequent chest CT showed a 1.1 cm right lower lobe sub-pleural nodule, 1.1 cm right paratracheal lymphadenopathy, and 1.47 cm subcarinal lymphadenopathy (Figure 1). Patient underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy of station 11R with pathology consistent with renal cell carcinoma. Patient was referred for nephrectomy followed by oncologic evaluation for further management with chemotherapeutic and possible immunological therapy. DISCUSSION: The incidence of pulmonary metastasis in RCC is approximately 50-60%.(3) Although commonly presenting as solitary or multiple nodules, pleural, lymphatics, or embolic phenomenon have been reported.(3) Interestingly, RCC can present with hilar or mediastinal lymphadenopathy. In cases where extensive pulmonary metastasis is present, RCC can be discovered during EBUS-TBNA, as noted in our case. (5) In our case, patient had positive lymph node for malignancy associated with the sub-pleural based nodule. It is possible that the lymphadenopathy was an indirect seeding after metastasis to right lower lobe nodule, or direct seeding into mediastinal and hilar lymph nodes. The presence of the right lower lobe nodule makes direct lymph node seeding less likely. CONCLUSIONS: In patients who present with hematuria with incidental findings of lymphadenopathy, it is worth considering RCC as a plausible diagnosis due to various pulmonary manifestations related to RCC. Reference #1: Chow, W., Dong, L., and Devesa, S. (2010). Epidemiology and risk factors for kidney cancer. Nature Reviews Urology. 2010; 7(5): 245-257. Kabaria, T., Klaassen, Z., and Terris, M. (2016). Renal cell carcinoma: links and risks. Int J Nephrol Renovasc Dis. 2016; 9: 45-52. Reference #2: Motzer, R., Bander, N., and Nanus, D. (1996). Renal-cell carcinoma. N Engl J Med 1996. 335(12): 865-875. Agarwal, A., Sahni, S., Iftikhar, A., and Talwar, S. (2015). Pulmonary manifestations of renal cell carcinoma. Respiratory Medicine 109: 1505-1508. Reference #3: Val-Bernal, J., Martino, M., Romay, F., and Yllera, E. (2018). Endobrnchial ultrasound-guided transbronchial needle aspiration in the diagnosis of mediastinal metastases of clear cell renal cell carcinoma. Pathology Research and Practice. 2018; vol 214 (7): 949-956. DISCLOSURES: No relevant relationships by Kushagra Gupta, source=Web Response No relevant relationships by Anthony Loschner, source=Web Response No relevant relationships by Elizabeth McCaskey, source=Web Response No relevant relationships by Toribiong Uchel, source=Web Response