Clinical Characteristics and Histopathology in Suspected Necrotizing Soft Tissue Infections

Area of Science:

• Infectious Diseases
• Pathology
• Surgical Pathology

Background:

• Necrotizing soft tissue infections (NSTIs) are severe, life-threatening conditions with diagnostic challenges.
• Current guidelines recommend tissue biopsies for NSTI diagnosis, but standardization and validation are lacking.
• The quality of tissue biopsy examination in routine NSTI diagnostics requires investigation.

Purpose of the Study:

• To evaluate the quality of tissue biopsy examination in the routine management of suspected NSTIs.
• To assess the diagnostic accuracy and interrater reliability of histopathologic evaluation for NSTIs.

Main Methods:

• Retrospective cohort study of adult patients with suspected NSTIs undergoing surgery.
• Evaluation of tissue biopsies using a proposed histopathologic classification system by two independent pathologists.
• Determination of interrater reliability and diagnostic accuracy metrics (sensitivity, specificity, PPV, NPV).

Main Results:

• Analysis of 75 biopsies (55 NSTIs, 20 non-NSTIs) revealed moderate (0.53) and fair (0.37) interrater reliability for staging and diagnosis, respectively.
• Histologic diagnosis demonstrated 75% sensitivity and 80% specificity, with a 91% PPV and 53% NPV.
• A more severe histological stage correlated with favorable outcomes (NICCE success), observed in 42% and 71% of stage 1 and 2 cases, respectively (P = .046).

Conclusions:

• Tissue biopsies exhibit low clinical accuracy and limited interrater reliability among experienced pathologists for NSTI diagnosis.
• Histopathologic evaluation is not recommended as a reliable component of contemporary NSTI management.
• Despite limitations, a more severe histological stage was associated with a better patient outcome.