The R classification of surgical resection margins in oncological surgery is critical for prognosis. An R1 resection is defined as:

• A Macroscopically incomplete resection with visible residual tumour
• B Complete resection with pathologically negative margins on frozen section
• C Microscopic residual tumour at the resection margin on histopathological examination ✓
• D Distant metastatic disease present at the time of surgery

Explanation

R classification: R0 — complete macroscopic and microscopic resection with tumour-free margins; R1 — microscopically incomplete resection (tumour present at the cut margin on histology) despite appearing macroscopically complete; R2 — macroscopically incomplete resection with visible residual tumour. R1 resection significantly worsens local recurrence rates and overall survival for most solid tumours. It should trigger consideration of re-excision, adjuvant radiotherapy, or intensified adjuvant systemic treatment.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.