Background: Risk stratification after colorectal cancer surgery remains challenging. We evaluated whether a perioperative ratio combining immediate postoperative lactate with preoperative albumin is associated with in-hospital mortality after elective colorectal resection. Methods: In this single-center retrospective cohort, 282 patients underwent open elective colorectal resection. The perioperative lactate-to-albumin ratio (LAR) was calculated as arterial lactate (mmol/L) divided by serum albumin (g/dL), and discrimination was assessed by receiver operating characteristic (ROC) analysis with age-adjusted association by Firth’s penalized logistic regression and fixed-model bootstrap validation. Results: Seventeen patients (6.0%) died in hospital, and mortality rose across LAR tertiles (2.1%, 5.3%, and 10.6%; p = 0.014). LAR showed moderate discrimination (AUC 0.73; 95% CI 0.58–0.87; optimism-corrected AUC 0.78), with no evidence of better discrimination than lactate or albumin alone. At the Youden threshold of 0.555, sensitivity was 76.5% and specificity 61.1%. The age-adjusted Firth odds ratio was 1.19 per 0.1-unit increase (95% CI 1.09–1.29). Conclusions: The perioperative lactate-to-albumin ratio was associated with in-hospital mortality after age adjustment in this single-center cohort. Given the small number of deaths and absence of external validation, LAR should be regarded as a candidate marker requiring prospective multicenter validation before clinical application.

Aims: Differentiating between benign and malignant thyroid nodules preoperatively is of critical clinical importance. This study aims to evaluate the effectiveness of the Systemic Immune-Inflammation Index (SII) and the Prognostic Nutritional Index (PNI), derived from routine laboratory tests, in the differential diagnosis of thyroid nodules.Methods: A retrospective analysis was conducted on 345 patients (215 benign, 130 malignant) who underwent surgery at a university hospital’s general surgery clinic between 2015 and 2025 and had definitive histopathological diagnoses. SII and PNI values were calculated from preoperative blood parameters. Group comparisons, bias-reduced logistic regression, and receiver operating characteristic (ROC) analysis were utilized to assess diagnostic performance.Results: No, statistically significant differences were found between the benign and malignant groups regarding SII (p=0.728) or PNI (p=0.299). After adjusting for age, gender, comorbidities, and histologic thyroiditis in logistic regression models, Neither Index showed a significant association with malignancy. ROC analysis demonstrated near-chance discriminatory ability for both SII (AUC: 0.511) and PNI (AUC: 0.467), indicating that these markers lack sufficient diagnostic accuracy.Conclusion: In this surgical cohort, preoperative SII and PNI showed no detectable stand-alone discrimination between benign and malignant thyroid pathology; whether they add value to ultrasonography and cytology remains to be tested.