Endoscopic indications for endoscopic mucosal resection of laterally spreading tumours in the colorectum

Abstract

Background: Laterally spreading tumours (LSTs) in the colorectum are usually removed by endoscopic mucosal resection (EMR) even when large in size. LSTs with deeper submucosal (sm) invasion, however, should not be treated by EMR because of the higher risk of lymph node metastasis. Aims: To determine which endoscopic criteria, including high magnification pit pattern analysis, are associated with sm invasion in LSTs and clarify indications for EMR. Methods: Eight endoscopic criteria from 511 colorectal LSTs (granular type (LST-G type); non-granular type (LST-NG type)) were evaluated retrospectively for association with sm invasion, and compared with histopathological findings. Results: LST-NG type had a significantly higher frequency of sm invasion than LST-G type (14% v 7%; p,0.01). Presence of a large nodule in LST-G type was associated with higher sm invasion while pit pattern (invasive pattern), sclerous wall change, and larger tumour size were significantly associated with higher sm invasion in LST-NG type. In 19 LST-G type with sm invasion, sm penetration determined histopathologically occurred under the largest nodules (84%; 16/19) and depressed areas (16%; 3/19). Deepest sm penetration in 32 LST-NG type was either under depressed areas (72%; 23/32) or lymph follicular or multifocal sm invasion (28%; 1/32 and 8/32, respectively). Conclusions: When considering the most suitable therapeutic strategy for LST-G type, we recommend endoscopic piecemeal resection with the area including the large nodule resected first. In contrast, LST-NG type should be removed en bloc because of the higher potential for malignancy and greater difficulty in diagnosing sm depth and extent of invasion compared with LST-G type.

Endoscopic resection of superficial gastrointestinal tumors

“…When analyzing the endoscopic features of 257 LSTs in order to assess which features correlated with the depth of invasion, unevenness of nodules, presence of large nodules, size, histological type, and presence of depression in the tumor were significantly associated with the depth of invasion [41] . In addition, LST-NG showed a higher frequency of sm invasion than LST-G (14% vs 7%) [42] . Presence of a large nodule in LST-G type was associated with higher sm invasion while pit pattern, sclerous wall change, and larger size were significantly associated with higher sm invasion in LST-NG type.…”

“…Therefore, it is advisable to perform endoscopic piecemeal resection for LST-G type with the area including the large nodule resected first. Besides, LST-NG type should be removed by en bloc resection (Figure 3) because of the higher potential of sm invasion when compared to that of the LST-G type [42] . A study from Germany reported that complications occurred in two patients of 57 patients after EMR in large colorectal neoplasia between 10 mm and 50 mm [43] .…”

Giant lateral spreading tumor in ulcerative colitis

“…3 LST are usually removed by endoscopic mucosal resection while in the presence of deeper sub-mucosal invasion they should be treated by surgery due to the higher risk of lymph node metastasis. 4 Here we briefly report a case of giant LST occurring in a patient with long-standing UC.…”

The Diagnosis and Treatment of Early-Stage Colorectal Cancer

“…LSTs can be further divided into two main classes: granular type (LST-G) and non-granular type (LST-NG) ( Figure 1). We know that LST-NG tumors of size more than (or equal to) 20 mm and LST-G tumors of size more than (or equal to) 30 mm harbor a significantly higher likelihood of submucosal invasion [12]; therefore, a careful evaluation of morphological features is crucial for the depth diagnosis.…”