What combination of clinical findings is suggestive of a specific renal pathology?

a) Costovertebral angle tenderness and red blood cell casts
b) Costovertebral angle tenderness and white blood cell casts
c) Costovertebral angle tenderness and granular casts
d) Costovertebral angle tenderness and hyaline casts

The combination of costovertebral angle tenderness and white blood cell casts in urine suggests a renal pathology, typically pyelonephritis or kidney infection.

Explanation:

The combination of clinical findings that is suggestive of a specific renal pathology is costovertebral angle tenderness and white blood cell casts. Costovertebral angle tenderness is commonly associated with conditions affecting the kidneys, such as pyelonephritis or kidney stones.

The presence of white blood cell casts in the urine is highly indicative of a kidney infection, or pyelonephritis. These casts are formed in the distal and collecting tubules of the kidney, and they indicate that the white blood cells have originated from the kidney itself rather than from contamination of the urine from the lower urinary tract.

Furthermore, the presence of white blood cells in the urine, otherwise known as pyuria, is a sign of a urinary tract infection, as mentioned in Chapter 25, section 31. Renal colic caused by kidney stones can also present with costovertebral angle tenderness but it's more likely to be associated with hematuria rather than white blood cell casts.