CRM
Also written as: CRM — circumferential resection margin
Circumferential resection margin; the closest distance between tumor and the surgical margin in circumferentially resected specimens.
Full Definition
The circumferential resection margin represents the minimum distance between malignant tissue and the surgical resection plane in specimens that are circumferentially excised, particularly in rectal and esophageal cancers. CRM measurement is critical for determining adequacy of surgical excision and predicting local recurrence risk. A positive CRM (tumor within 1mm of the resection margin) significantly increases the likelihood of local recurrence. This measurement is distinct from proximal and distal margins and requires careful pathological assessment with ink marking of the surgical surface. CRM status directly influences adjuvant treatment decisions and long-term oncological outcomes.
Usage
Usage note: Always specify measurement distance; distinguish from other margin types in multi-dimensional specimens.
In Context
- "The CRM was involved with tumor cells extending to within 0.5mm of the resection plane." — Pathology report
- "A negative CRM of >1mm is associated with improved local control in rectal cancer." — Research paper