Pulmonary sarcoidosis as a cause of intermittent fever of unknown origin in a hemodialysis patient with renal cell carcinoma: A case report and literature review

: Hemodialysis patients have weakened immune systems and can exhibit fever due to various causes. Herein, we describe the case of a 61-year-old hemodialysis patient who exhibited intermittent low-grade fever after a pacemaker had been implanted 2 months before due to sick sinus syndrome. She had a medical history of subcutaneous sarcoidosis and uveitis. Active pulmonary sarcoidosis was diagnosed based on elevated soluble interleukin-2 receptor, elevated lysozyme level, and gallium-67 scintigraphy uptake in hilar and mediastinal lymph nodes. She was also diagnosed with renal cell carcinoma via contrast computed tomography. However, because her C-reactive protein level remained normal, the possibility of neoplastic fever was considered low. After the initiation of prednisolone administration, her fever gradually disappeared. Her serum soluble interleukin-2 receptor and lysozyme level improved in parallel with the enlargement of the mediastinal lymph node and gallium-67 scintigraphy uptake.