Table 3. Essential Elements in the Surgical Pathology Report for a Malignant Polyp.
| Features | Categories | Methods/criteria | Required/preferably | Clinical significance |
|---|---|---|---|---|
| Polyp configuration | Pedunculated | Well-developed stalk | Yes | Recurrence risk |
| Semipedunculated | Short stalk | |||
| Sessile | No stalk | |||
| Procedure | Polypectomy | Acquire information from the endoscopic report | Yes | Recurrence risk |
| EMR | ||||
| ESD | ||||
| Specimen intactness | En bloc | One piece | Yes | Recurrence risk |
| Piecemeal | More than one piece | |||
| Invasive adenocarcinoma | Present | Infiltrative glands below MM | Yes | Nodal metastasis risk; may require resection |
| Absent | All neoplastic glands are above MM | |||
| Size of invasive adenocarcinoma | Continuous variable | Only measure the size of the invasive component | Yes | None |
| Grade | Well | > 95% glandular formation | Yes | Poor differentiation prompts a resection. |
| Moderate | 50-95% glandular formation | |||
| Poor | < 50% glandular formation | |||
| LVI | Small vessel LVI | Tumor cells within endothelium lined spaces | Yes | Presence of LVI prompts a resection. |
| Muscular venous invasion | Tumor cells present in a muscular vein | |||
| Deep margin status | Positive | Invasive carcinoma at or within 1 mm from the margin | Yes | Positive margin prompts a resection. |
| Negative | Invasive carcinoma greater than 1 mm from the margin | |||
| Indeterminate | Applies to piecemeal specimen | |||
| Depth of submucosal invasion | Pedunculated polyp | From the head-stalk junction to the deepest invasion | Yes | Invasion ≥ 1,000 µm into the submucosa prompts a resection. |
| Sessile polyp | From MM to deepest invasion | |||
| From the most superficial portion of invasion to the deepest invasion if MM absent | ||||
| Tumor budding (in an area measuring 0.785 mm2) | Low level | 1 - 4 tumor buds | Yes | Intermediate or higher tumor budding may prompt a resection in some practices. |
| Intermediate level | 5 - 9 tumor buds | |||
| High level | 10 or more tumor buds | |||
| Micropapillary features | Present | Presence of small and tight clusters of tumor cells within cleft-like spaces | Preferably | Risk for LVI and nodal metastasis, poor prognosis |
| Absent | Absence of small and tight clusters of tumor cells within cleft-like spaces | |||
| Immunohistochemistry for MMR proteins | Intact | Nuclear immunoreactivity | Yes | Loss of MMR leads to workup for LS. |
| Loss | Absence of nuclear immunoreactivity |
EMR: endoscopic mucosal resection; ESD: endoscopic submucosal dissection; MM: muscularis mucosae; LVI: lymphovascular invasion; MMR: mismatch repair; LS: Lynch syndrome.