Histologic Evaluation of Malignant Polyps and Low-Stage Colorectal Carcinoma

My approach to assessing for colorectal polyp cancer

Assessing a locally excised colorectal adenoma for malignancy is a common but often challenging scenario. This article outlines a simple, stepwise approach to this diagnostic assessment. The first steps are to assess for high-grade dysplasia and, if present, to determine whether any neoplastic glands lie within the submucosa. If so, a distinction must then be made between epithelial misplacement and adenocarcinoma; this process is aided by certain clinical and endoscopic data together with assessment of six key histological features. If adenocarcinoma is diagnosed, a final step is to report the presence/absence of high-risk features of polyp cancers because this will then determine if further surgical resection is required for that malignancy. Caveats, uncertainties and newly introduced concepts exist at several steps of the assessment pathway presented and are therefore discussed in detail throughout the article.

Estimation of risk posed by malignant polyps amongst colorectal surgeons in Australia and New Zealand

PURPOSE

The estimation of the risk posed by malignant polyps for residual or lymphatic disease plays a central role. This study investigated colorectal surgeons' assessment of these risks associated with malignant polyps.

METHODS

A cross-sectional questionnaire was electronically administered to colorectal surgeons in Australia and New Zealand in October 2022. The questionnaire contained 17 questions on demographics, when surgeons consider colorectal resection appropriate, and the risk assessment for 5 hypothetical malignant polyps.

RESULTS

The mean risk of residual or lymphatic disease that would prompt surgeons to recommend colonic resection was 5%. However, this increased to a mean risk of 10% if the malignant polyp was located in the rectum, and the only resection option was abdominoperineal resection with end-colostomy. There was high concordance between the estimated risk of residual or lymphatic disease by colorectal surgeons and the Association of Coloproctology of Great Britain and Ireland (ACPGBI) guidelines for the 5 hypothetical malignant polyps, with the ACPGBI estimated risk lying within the 95% confidence interval for 4 of the 5 malignant polyps. Nonetheless, 96.6% of surgeons felt that an online risk calculator would improve clinical practice.

CONCLUSION

Colorectal surgeons in Australia and New Zealand accurately estimated the risk posed by malignant polyps. An online risk calculator may assist in better conveying risk to patients.

Essentials of macroscopic evaluation of specimens from gastrointestinal tract

An astute macroscopic examination, coupled with correlating the gross findings with clinical indication and operative notes along with judicious, yet all pertinent sectioning for pathological examination is crucial for an accurate histopathological diagnosis, eventually leading to optimal patient care. This succinct review highlights the general concepts that lay the foundation of evaluating and grossing specimens from the luminal gastrointestinal (GI) tract. We also discuss the gross evaluation and sectioning of small therapeutic resections, along with a systematic approach and rationale when grossing and submitting histological sections from larger oncological resections from the luminal GI tract. Selected site-specific considerations, for example, grossing treated rectal and oesophageal cancers or taking sections from mucinous tumours of the appendix, among others, are also discussed.

Malignant Colorectal Polyps: Are Pathology Reports Sufficient for Decision Making?

AIM

This study aims to assess the completeness of pathology reports of T1 colorectal cancers from different healthcare centers and the change of treatment decision after reevaluation of the polyps.

MATERIALS AND METHODS

In this single-center retrospective cohort study, several pathology reports of endoscopically excised malignant colorectal polyps at diverse healthcare centers in Turkey were reassessed at a comprehensive cancer center in Istanbul. Reassessment was mainly focused on core elements such as the size of invasive carcinoma, histologic type and grade, tumor extension, surgical margin (deep and mucosal), and lymphovascular invasion.

RESULTS

Sixty-seven endoscopically resected malignant polyps were analyzed. The mean age of patients was 62.2 years and 38 (58%) patients were males. Tumor size, histologic type and grade, surgical margin (deep and mucosal), and lymphovascular invasion were reported in 11%, 100%, 31%, 9%, and 19%, respectively. All 5 prognostic factors were reported only in 1 (1.5%) pathology report. Because of the missing (incomplete) data, the pathologic examination of 59 (88%) patients was determined to be inadequate to make an accurate treatment decision.

CONCLUSION

Several variables are not considered and frequently missing for decision-making, suggesting the reassessment of the specimen by a second pathologist at a high-volume comprehensive cancer center.

Pitfalls in the reporting of neoplastic and pseudo neoplastic lesions in the colon and rectum

INTRODUCTION

Colonic biopsies comprise large portion of pathologists' daily work. Within various pathological entities, there are histological ranges and variations. Unawareness of all of these variabilities might lead to misdiagnosis by an inexperienced pathologist and, accordingly, to mismanagement.

Colorectal malignant polyps: a modern approach

Colorectal malignant polyps (MP) are polyps with invasive cancer into the submucosa harboring a variable risk of lymph node involvement, which can be estimated through evaluation of morphological, endoscopic, and histologic features. The recent advances in imaging endoscopic techniques have led to the possibility of performing an optical diagnosis of T1 colorectal cancer, allowing the selection of the best therapeutic modality to optimize outcomes for the patient. When MP are diagnosed after endoscopic removal, their management can be challenging. Differentiating low- and high-risk histologic features that influence the possibility of residual tumor, the risk of recurrence and the risk of lymph node metastasis, is crucial to further optimize treatment and surveillance plans. While the presence of high-risk features indicates a need for surgery in the majority of cases, location, comorbidities and the patient’s preference should be taken in account when making the final decision. This is a particularly important issue in the management of low rectal MP presenting with high-risk features, where chemoradiotherapy followed by a watch-and-wait strategy has demonstrated promising results. In this review we discuss the important prognostic features of MP and the most modern approaches regarding their management.

Factors predicting occurrence and therapeutic choice in malignant colorectal polyps: a study of 13 years of colonoscopic polypectomy

Colorectal carcinoma represents a major cause of mortality and 0.2–12% of resected colonic polyps have malignant cells inside. We performed a retrospective study of patients with resected polyps during a period of 13 years. A total of 905 patients had 2033 polyps removed; 122 polyps (109 patients) had malignant cells. Prevalence of malignant polyps with submucosal invasion was 1.23% and for all polyps with malignant cells was 6%; malignant polyps had a larger size (23.44 mm mean diameter) vs benign polyps (9.63 mm); the risk of malignancy was increased in polyps larger than 10 mm, in lateral spreading lesions and in Paris types 0-Ip, 0-Isp, in sigmoid, descending colon and rectum, in sessile serrated adenoma and traditional serrate adenoma subtypes of serrated lesions and in tubulovillous and villous adenoma. In 18 cases surgery was performed, in 62 patients only colonoscopic follow-up was made and in 35 patients no colonoscopic follow-up was recorded. From initially endoscopic resected polyps, recurrence was noted in seven (11.3%) cases; there was a trend toward association with depth of invasion, piecemeal resection, right and rectum location, sessile and lateral spreading type and pathological subtype. In surgical group, post-therapeutic staging was available in 11 cases; nodal involvement was noted in three (27.27%) cases; none had lymphatic or vascular invasion in endoscopically resected polyps. Four patients with no macroscopic local recurrence underwent surgery with no residual tumor. The rate of metastasis was 16.67% in surgical group and 1.61% in endoscopic group. Evaluation of lymph node (LN) invasion was available for 11 operated patients, with LN invasion (N1) in three patients, local residual tumoral tissue in one patient with incomplete resection and no residual tumor (R0 resection) in four patients with endoscopic resection before surgery.