A 55-year-old African-American male with a history of obesity, tobacco use, and hypertension presents with hematuria and flank pain. What is the most likely diagnosis?

The clinical presentation of hematuria (blood in the urine) and flank pain in this patient is highly suggestive of renal cell carcinoma. This type of cancer is often associated with risk factors that align with the patient's history, including obesity, tobacco use, and hypertension. Renal cell carcinoma is known to cause a classic triad of symptoms: hematuria, flank pain, and a palpable mass; however, the first two symptoms can often be present even in the absence of a mass.

In the context of the patient's demographics, being an African-American male in his 50s increases his risk for various health conditions, including renal cell carcinoma. The location of the pain, coupled with the hematuria, suggests that a renal origin is likely. The risk factors combined with these symptoms lead to a strong suspicion of renal cell carcinoma as the most probable diagnosis.

While prostatitis, acute pyelonephritis, and diverticulitis can also present with flank pain and changes in urinary symptoms, they typically have additional specific symptoms and a different age or risk profile. Prostatitis primarily presents with pelvic pain and urinary symptoms, acute pyelonephritis tends to cause fever and chills alongside flank pain, and diverticulitis is characterized by abdominal