Histopathologic Diagnostic Agreement Study in Bone and Soft Tissue Tumors: The SELNET Sarcoma Network Experience.

Area of Science:

• Oncology
• Pathology
• Medical Diagnostics

Background:

• Accurate histopathologic diagnosis is crucial for sarcoma patient management.
• The Sarcoma European and Latin-American Network (SELNET) aims to standardize sarcoma care.
• Variability in local diagnostic expertise can impact patient outcomes.

Purpose of the Study:

• To determine the rate of histopathologic diagnostic concordance between local reviewers and expert pathologists within the SELNET consortium.
• To identify the primary causes of diagnostic discrepancies in bone and soft tissue tumors.

Main Methods:

• A review of 347 bone and soft tissue tumor cases diagnosed at local SELNET centers over three years.
• Comparison of local histopathologic diagnoses with expert re-evaluations by SELNET pathologists.
• Analysis of concordance rates and reasons for discordance.

Main Results:

• A high diagnostic concordance rate of 85.3% (Cohen's κ = 0.84) was observed between local and expert SELNET pathologists.
• 14.7% of cases (51/347) showed diagnostic discordance, with 19 cases classified as major due to potential clinical management changes.
• The main causes of discordance were incorrect morphologic interpretation (37.2%) and lack of immunohistochemical markers (41.2%) or molecular testing (21.6%).

Conclusions:

• A substantial diagnostic agreement exists within the SELNET network for bone and soft tissue tumors.
• Improving morphologic assessment, utilizing advanced immunohistochemical markers, and incorporating molecular analysis can help resolve diagnostic discrepancies.
• Standardized expert review enhances diagnostic accuracy and potentially improves patient care pathways.