Chest radiographic findings suggestive of possible sarcoidosis in patients with nephrolithiasis

Renal involvement in sarcoidosis may manifest as hypercalcemia, hypercalciuria, nephrolithiasis, nephrocalcinosis, and other abnormalities, but is often underrecognized. This study investigated chest radiographic findings suggestive of possible sarcoidosis in patients with nephrolithiasis and compared available laboratory parameters between patients with and without such findings. This retrospective analytical cross-sectional study included patients undergoing PCNL or TUL for urinary stones at Razi Hospital (Guilan, Iran) from 2016 to 2021. Routine preoperative chest X-rays were reviewed; 1297 encounters had both a retrievable diagnostic-quality CXR and available core laboratory data. Two pulmonologists independently interpreted CXRs for findings suggestive of possible sarcoidosis and assigned Scadding stage (0-IV), each blinded to the other's assessment; discrepancies were adjudicated by a third pulmonologist. Preoperative laboratory variables (BUN, creatinine, uric acid, alkaline phosphatase, calcium, phosphorus, AST, ALT, and CBC) were extracted and compared between patients with radiographic findings suggestive of possible sarcoidosis (RFS group) and those without such findings (non-RFS group) using Mann-Whitney U tests and chi-square/Cochran-Armitage trend tests. Logistic regression was used to examine the association between elevated creatinine and RFS. Radiographic findings suggestive of possible sarcoidosis were identified in 2.5% of patients, most commonly in middle-aged men and predominantly as Scadding stage I patterns. Creatinine levels were higher in the RFS group than in the non-RFS group. Elevated creatinine was associated with RFS in unadjusted analysis but not after adjustment for age and sex. Radiographic findings suggestive of possible sarcoidosis were identified in a small subset of nephrolithiasis patients. Although higher creatinine levels were observed in this group, this finding should be interpreted cautiously. Chest radiography may help identify patients who warrant further evaluation, but prospective studies incorporating confirmatory diagnostic methods are needed to clarify the clinical significance of these findings.