A 64-year-old man comes to the office due to several episodes of intermittent hematuria over the past 2 months. He has had no abdominal pain, burning on urination, or fever but has lost 4.5 kg (10 lb) since the onset of symptoms. The patient has smoked a pack of cigarettes daily for 30 years. Vital signs are within normal limits. The abdomen is soft, nontender, and nondistended. An enlarged and firm prostate is palpated on digital rectal examination. Serum calcium is 12.3 mg/dL. Urinalysis shows 30-40 red blood cells/hpf, negative protein, and no casts. A CT scan of the abdomen is shown below. Which of the following is the most likely diagnosis?

Question

A 64-year-old man comes to the office due to several episodes of intermittent hematuria over the past 2 months.  He has had no abdominal pain, burning on urination, or fever but has lost 4.5 kg (10 lb) since the onset of symptoms.  The patient has smoked a pack of cigarettes daily for 30 years.  Vital signs are within normal limits.  The abdomen is soft, nontender, and nondistended.  An enlarged and firm prostate is palpated on digital rectal examination.  Serum calcium is 12.3 mg/dL.  Urinalysis shows 30-40 red blood cells/hpf, negative protein, and no casts.  A CT scan of the abdomen is shown below.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec160b_3a4d_eec6_9249_9114c251b284_MD0001_00 This patient with an extensive smoking history, 4.5-kg weight loss, painless hematuria, hypercalcemia, and renal mass (arrow) likely has renal cell carcinoma (RCC). RCC originates in the renal cortex and accounts for up to 90% of primary renal tumors. It is often identified incidentally on radiographic imaging, and many individuals remain asymptomatic until the disease is relatively advanced. Hematuria is the most common symptom, and painless hematuria in an adult should raise suspicion for a genitourinary malignancy. Patients may also have flank pain and a palpable abdominal mass at the time of presentation. Paraneoplastic syndromes are common in RCC due to the secretion of biologically active substances by the tumor cells. Hypercalcemia is frequently seen due to increased production of parathyroid hormone-related peptide or overproduction of prostaglandins that promote bony resorption. Erythrocytosis (due to ectopic erythropoietin production) and hepatic dysfunction unrelated to liver metastases may also be seen. (Choice A) Bladder cancer is another common cause of hematuria and weight loss; however, CT scan would demonstrate a bladder mass. This malignancy tends to metastasize to the liver, bones, and lungs, not the kidney. Although hypercalcemia may occur occasionally, it is more strongly associated with RCC. (Choice B) Pheochromocytoma can cause severe, episodic hypertension associated with headaches, anxiety, palpitations, and sweating. A CT scan would reveal a suprarenal mass, and urine catecholamines and metanephrine would be elevated. Hematuria is not seen. (Choice C) Polycystic kidney disease can cause hematuria; however, flank pain is common, and imaging would show bilateral renal cysts, not a unilateral mass. In addition, weight loss and hypercalcemia would be unexpected. (Choice D) Prostate cancer typically presents with discrete nodules or asymmetric induration of the prostate on digital rectal examination. Diffuse, symmetric enlargement and firmness of the prostate are more suggestive of benign prostatic hyperplasia. (Choice F) Ureterolithiasis is a common cause of hematuria, and patients with hypercalcemia from other causes (eg, hyperparathyroidism) are predisposed to stone formation. Although there are small kidney stones on this patient's imaging, this would not explain the large renal mass and unintended weight loss, which are highly suggestive of malignancy. Educational objective: Classic signs and symptoms of renal cell carcinoma (RCC) include hematuria, an abdominal mass, flank pain, and weight loss. Hypercalcemia and erythrocytosis are common paraneoplastic syndromes associated with RCC.

A 64-Year-Old Man Comes to the Office Due to Several