Differential Diagnosis for 49-year-old Male Patient with Hematuria and Left Flank Pain

Single Most Likely Diagnosis

• Ureteral Calculus: The patient's symptoms of hematuria, left flank pain, and the inability to urinate without a catheter, combined with the radiographic finding of a potential 6.5 x 2 mm calculus within the distal left ureter, make this the most likely diagnosis. The presence of a calcific body in the distal left ureter, as seen on the KUB (Kidneys, Ureters, Bladder) radiograph, strongly supports this diagnosis.

Other Likely Diagnoses

• Urinary Tract Infection (UTI): The patient's symptoms of hematuria and left flank pain could also be indicative of a UTI, especially given the elevated WBC count and the presence of blood in the urine. However, the radiographic findings and the clinical presentation more strongly suggest a ureteral calculus.
• Bladder Outlet Obstruction: The patient's inability to urinate without a catheter and the prescription of Tamsulosin (an alpha-blocker used to treat benign prostatic hyperplasia and bladder outlet obstruction) suggest that bladder outlet obstruction could be a contributing factor to his symptoms.

Do Not Miss Diagnoses

• Kidney Cancer: Although less likely, given the patient's age and symptoms, kidney cancer could present with hematuria and flank pain. It is crucial to consider this diagnosis to ensure timely diagnosis and treatment if present.
• Sepsis: The elevated WBC count and the presence of a potential infection (suggested by the UTI consideration) necessitate consideration of sepsis, especially if the patient shows signs of systemic infection such as fever, tachycardia, or hypotension.

Rare Diagnoses

• Sickle Cell Disease: Although rare in a 49-year-old presenting for the first time, sickle cell disease can cause renal complications, including hematuria and renal infarction, due to sickling in the renal medulla.
• Renal Tubular Acidosis: This rare condition can cause kidney stones, nephrocalcinosis, and other renal abnormalities, potentially leading to hematuria and flank pain.
• Amyloidosis: A rare condition that can affect the kidneys, causing proteinuria, hematuria, and renal failure. Given the patient's age and the absence of other systemic symptoms, this is less likely but should be considered in the differential diagnosis if other causes are ruled out.