Differential Diagnosis for Renal Calcifications
The patient's presentation of dysuria, frequent urination, intermittent gross hematuria, and chronic low back pain, along with a history of multiple urinary tract infections and acute pyelonephritis, suggests a condition affecting the kidneys. The presence of large calcifications in both kidneys on plain films of the abdomen is a key finding. Here is a differential diagnosis for the composition of these calcifications:
Single most likely diagnosis
- Magnesium-ammonium-phosphate (Struvite stones): This is the most likely composition given the patient's history of recurrent urinary tract infections, which often involve urease-producing bacteria. These bacteria increase the urine pH, leading to the formation of struvite stones. The patient's urine pH of 8.0 and the presence of leukocyte esterase and nitrite further support this diagnosis.
Other Likely diagnoses
- Calcium oxalate monohydrate: While less likely than struvite stones given the clinical context, calcium oxalate stones are common and could be considered, especially if the patient had other risk factors such as hypercalciuria or hyperoxaluria.
- Calcium oxalate dehydrate: Similar to calcium oxalate monohydrate, this could be a consideration but is less likely given the specific clinical scenario.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cystine: Although less common, cystinuria is an important consideration because it is associated with a significant risk of stone recurrence and potential kidney damage if not properly managed. It is crucial to identify this condition due to its implications for long-term management and potential genetic counseling.
Rare diagnoses
- Uric acid: Uric acid stones are less likely in this scenario due to the absence of specific risk factors such as gout, high dietary purine intake, or conditions leading to high cell turnover. However, they could be considered in the differential diagnosis, especially if other causes are ruled out.
- Other rare stone compositions, such as those associated with certain medications or genetic disorders, are also possible but are less likely given the patient's presentation and history.