A RARE PRESENTATION OF RENAL CELL CARCINOMA: PARANEOPLASTIC COUGH

ABSTRACT

CASE A 30-year-old woman with a history of hypertension, obesity, and reactive airway disease presents with a two-month history of persistent cough, wheeze, and diaphoresis. At that time, chest x-ray and COVID-19 PCR were negative and pulmonary function tests were within normal limits. Her symptoms were managed with inhaled corticosteroid/long-acting muscarinic antagonist, albuterol, guaifenesin, and second-generation antihistamines. However, she continued to be symptomatic. Two months after these symptoms arose, she presented to the ED with a sixhour history of sudden onset right non-radiating flank pain. Her symptoms were associated with acute onset nausea, vomiting, urinary frequency, urgency, hesitancy, and burning;negative for hematuria. She was hemodynamically stable and physical exam was significant for right flank tenderness. Urinalysis showed proteinuria of 100 mg/dL and gross hematuria. Imaging of the abdomen demonstrated an enlarged right kidney with a large mass involving the cortex with mass effect on the liver. Urology performed a right radical nephrectomy with pathology positive for chromophobe renal cell carcinoma. Following surgery, the patient's original symptoms of cough, wheezing, and diaphoresis resolved. IMPACT/DISCUSSION: The typical symptomatic presentation of renal carcinoma with flank pain, abdominal mass, hematuria, and weight loss occurs in roughly 9% of cases and is indicative of advanced disease. Renal cell carcinoma is most commonly found incidentally on imaging studies, leading to improved outcomes due to early recognition. Young patients, however, are more likely to present symptomatically. Our patients' initial presentation of cough could be due to two different mechanisms. One possibility is chronic irritation of the diaphragm due to mass effect from the growing tumor. This mechanism is possible in our case as there was minor mass effect on the liver which could then disturb the diaphragm. A more likely mechanism is a paraneoplastic process. This has been demonstrated in prior cases with a chronic unremitting cough associated with diaphoresis, not improved with anti-tussives, and resolves upon removal of the mass. The cough has been shown to return with metastases. The proposed mechanism is tumor secretion of prostaglandins which enhance the cough reflex. Our case displays an uncommon symptomatic presentation of renal cell carcinoma in a young woman due to paraneoplastic cough stimulation. This demonstrates the importance of digging deeper when common symptoms such as cough are not successfully resolved with typical treatments. CONCLUSION: Most commonly renal cancer is diagnosed on incidental imaging allowing clinicians to make a diagnosis before symptoms arise. An unremitting cough may be an early warning sign of renal cell carcinoma before urinary symptoms begin, making early diagnosis more likely. Due to this, seemingly minor symptoms such as cough should be followed through to diagnosis as they can have significant consequences.