Micrograph of a stained slide of a resected myopericytoma, the<unk>  stained brown A<unk>  or surgical<unk>  is the<unk>  of apparently non-tumorous tissue around a tumor that has been surgically removed, called "resected", in surgical oncology. The<unk>  is an attempt to remove a cancer tumor so that no portion of the malignant growth extends past the edges or<unk>  of the removed tumor and surrounding tissue. These are retained after the surgery and examined microscopically by a pathologist to see if the<unk>  is indeed free from tumor cells. If cancerous cells are found at the edges the operation is much less likely to achieve the desired results. Residual tumour at the primary site after treatment (it does not address the surgical<unk>  as commonly believed) is classified by the pathologist as (AJCC 8th Edition): * R0 - no cancer cells seen microscopically at the primary tumour site. * R1 - cancer cells present microscopically at the primary tumour site. * R2 - Macroscopic residual tumour at primary cancer site or regional lymph nodes. It does not include metastatic disease identified but not sampled at the time of surgery. Micrograph showing a positive cauterized surgical<unk>  in an adenocarcinoma (center-top of image). H&E stain. The<unk>  Status following tumour<unk>  (AJCC 8th Edition): * Negative<unk> : No tumour at the<unk> . * Microscopic positive<unk> : Tumour identified microscopically at the<unk> . * Macroscopic positive<unk> : Tumour identified grossly at the<unk> . *<unk>  not assessed. The size of the<unk>  is an important issue in areas that are functionally important (i.e., large vessels like the aorta or vital organs) or in areas for which the extent of surgery is minimized due to aesthetic concerns (i.e., melanoma of the face or squamous cell carcinoma of the penis). The desired size of<unk>  around the tumour can vary. In<unk> s for breast cancer, there appears to be a difference between European and American radiation oncologists, with the former preferring larger<unk> s of over 5 mm. Apart from traditional methods looking at stained "shaves" (thin slices of tissue removed from the edge of the<unk>  or smeared and stained imprints, more recent techniques used to assess<unk> s include x-rays with compression, frozen specimens, and new techniques such as optical coherence tomography and quantitative diffuse reflectance spectroscopy.
Resection margin
Periwound
TNM staging system
BI-RADS
PI-RADS
Sentinel lymph node
Port 
Perineural invasion