deep margin
The surgical margin closest to the chest wall or pectoralis fascia in breast-conserving surgery, critical for assessing complete tumor excision.
Full Definition
The deep margin represents the deepest aspect of the surgical specimen in breast-conserving surgery, typically corresponding to the tissue closest to the pectoralis fascia or chest wall. This margin is particularly important in surgical pathology assessment because positive deep margins may indicate residual tumor extending toward the chest wall, potentially requiring re-excision or conversion to mastectomy. The deep margin status significantly influences surgical planning and patient outcomes, as it represents the area most difficult to re-excise if positive.
Usage
Usage note: Always specify as 'deep margin' rather than 'deep surgical margin' in pathology reports for consistency.
In Context
- "The deep margin was involved by invasive carcinoma, measuring less than 1 mm from the inked surface." — Pathology report
- "Additional tissue was taken from the deep margin to ensure clear surgical margins." — Operative report