Malignant colonic adenomas. Therapeutic criteria: Long-term results of therapy in a series of 42 patients in our healthcare area

Abstract

Objective: a) to evaluate the appropriateness of histological criteria as proposed by Morson as indicators for surgery; and b) to compare the adequacy of Morson's criteria with Haggitt's levels as indicators for surgery in the case of malignant sessile lesions. Material and methods: we carried out a prospective, protocolized study of 42 patients with polyps with invasive carcinoma (IC) who underwent colonoscopic polypectomy from 1979 through 2008. We applied the histological criteria proposed by Morson to all the patients included in the series. Results: we treated 24 polyps with IC and favorable histological criteria (FC) and 18 polyps showing unfavorable histological criteria (UC). All polyps with FC were treated by means of colonoscopic polypectomy. None of the patients showed signs of disease after a mean follow-up period o f 9.67 yrs. Patients with polyps with UC were recommended to undergo surgery. The presence of unfavorable histological criteria in the polypectomy sample was clearly associated with an unfavorable patient outcome and showed a 100% sensitivity level, a negative prognostic value (NPV) of 100%, and a false negative (FN) percentage of 0% for the prognosis of the disease. We found 12 sessile polyps (Haggitt's level 4). Colonoscopic polypectomy was the treatment employed in 9 out of 12 cases. All patients are free from disease (mean follow-up 7.3 yrs). If Haggitt's level criteria had been applied, all 12 patients would have undergone surgery. This means 58% more patients than following Morson's criteria. Conclusions: Morson's criteria are considered an adequate diagnostic tool for the indication of surgery in patients with malignant adenomas. Haggitt's invasion levels do not accurately discriminate the necessity for surgery in case of malignant sessile lesions.

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

“…Rate of malignancy was 29.17% for TSAs, 17.02% for SSA, 13.7% for villous and tubulovillous lesions, 0.9% for tubular polyps. The data for traditional adenomas are similar to that from the literature, where a greater risk for malignancy was noted in VA [ 20 , 37 ], with one study showed that 66% of malignant polyps had a villous component [ 37 ]. For serrated polyps (TSAs and SSAs), the rate of malignancy in our study was much higher than in literature data (1.3% for SSAs and 0.7% for TSAs) [ 41 ], although SSAs of the right colon have been frequently incriminated into the etiology of interval cancers between screening colonoscopies [ 41 ].…”

“…The mean diameter of malignant polyps was 23.44 mm (4–90 mm) and for benign polyps 9.63 mm (3–70 mm) ( p <0.0001); the difference was statistically significant but there are some larger benign polyps in our study. In various small studies, the mean diameter of malignant polyps was between 18.6–25 mm [ 4 , 20 , 31 , 36 ], one large study found a mean diameter of 20.6±13.1 mm for LN negative and of 19.6±9.9 mm for LN positive [ 35 ], and another large study found a mean diameter of 17 mm [ 37 ]. The risk of malignancy increases with size: 0.81% below 10 mm, 14.1% above 10 mm, 25.8% above 20 mm and 30% above 30 mm, comparable to other studies [ 17 , 30 , 37 ].…”

“…56.56% of malignant polyps in our study were located to the left colon, 27.87% in the rectum and 15.57% in the right colon. Most malignant polyps had a left-side location [ 20 , 32 , 40 ] and in one large study with 19 743 patients [ 37 ] 55% of malignant polyps were located to the left colon, followed by right colon (31%) and transverse colon and flexures (13%).…”

“…Several pathological factors can predict the risk of recurrence and/or LN invasion: resection border (above 1 mm but even 0.1 mm in some studies) [ 3 , 6 , 8 , 18 , 19 , 20 ], depth of invasion [ 3 , 6 , 7 , 21 ] (Table 2 ), pedunculated vs sessile type [ 3 , 6 , 7 , 21 ], differentiation grading (higher risk in G3 grade and in mucinous, signet ring and micropapillary carcinoma) [ 7 , 8 ], lymphovascular invasion [ 1 , 3 , 8 ] and tumoral budding [ 1 , 8 , 22 , 23 ]. LN involvement is very important because in case of resected colorectal T1 SM carcinoma polyps a LN invasion can demand surgical intervention, while cases with no LN involvement can be managed only by local close surveillance [ 1 ].…”

Value and Interpretation of Resection Margin after a Colonoscopic Polypectomy for Malignant Polyps

“…However, the aforementioned criteria could only be applied in cases of complete resection into a single piece. For piecemeal resection, surgical treatment should be considered due to low pathohistological accuracy [8]. …”