Gastrointestinal stromal tumours: a regular origin in the muscularis propria, but an extremely diverse gross presentation

Abstract

EGISTs are probably rarer than previously reported (1.5% or less in this study). We concluded that most so-called EGISTs represent apparent EGISTs that should have arisen from the outermost muscle coat, but have lost their contact to the point of origin due to extensive extramural growth pattern. From a surgical point of view, it is crucial to document and mark any focal attachment or adhesions to the gut wall noticed during surgery for an apparent EGIST. In contrast to most other neoplasms, GISTs should be defined by virtue of any degree of association with the muscularis propria (no matter how minimal), but not by localisation of the bulk of the tumour.

A Single-Institution Experience with Eight CD117-Positive Primary Extragastrointestinal Stromal Tumors: Critical Appraisal and a Comparison with Their Gastrointestinal Counterparts

“…The aim of the present study is to report on a single-institution experience with EGISTs to determine its incidence and to compare its clinicopathological features with typical GISTs in order to provide further insight into their possible origin. Similar to the proposal of Agaimy and Wunsch, 3 we hypothesize that true EGISTs are very rare, and their occurrence is likely a result of extensive extramural growth of mural GISTs.…”

“…This is because although ICCs have been reported to occur in the pancreas, 14 thus far it has not been convincingly demonstrated to arise at other sites outside the gastrointestinal tract. 3,11 These investigators have instead proposed that GISTs and EGISTs may arise from a common precursor cell of ICC and smooth muscle which may account for their growth from and outside the gastrointestinal tract. On the other hand, other investigators have proposed a simpler explanation accounting for the occurrence of EGISTs suggesting that these are in actual fact mural GISTS with extensive extramural growth resulting in eventual loss of their connection with the gut wall.…”

“…On the other hand, other investigators have proposed a simpler explanation accounting for the occurrence of EGISTs suggesting that these are in actual fact mural GISTS with extensive extramural growth resulting in eventual loss of their connection with the gut wall. 3 Presently, despite numerous studies reporting on GISTs arising from the gastrointestinal tract, there have been limited studies specifically addressing EGISTs with the exception of small case reports. 1,3,6,11 To the best of our knowledge, to date only six series on EGISTs [1][2][3]6,11,15 have been reported in the English literature of which five 1-3,6,11 were multi-institution pathological studies.…”

Extragastrointestinal Stromal Tumour of The Abdominal Wall - A Case Report

“…A majority of the cases are considered as metastases or a result of loss of contact with a primary intra-abdominal tumour [1,6]. Our case did not reveal any primary source and the histomorphology, along with immunohistochemical (IHC) analysis, helped in diagnosing it to be as a primary EGIST of the abdominal wall.…”

Clinical and morphological characteristics of gastrointestinal stromal tumors

“…В ранних рабо-тах упоминалось, что распространенность ГИСО с лока-лизацией за пределами ЖКТ может достигать 10% [57]. Однако результаты работы A. Agaimy и P. Wunsch [58] сви-детельствуют, что значительная часть этих экстрагастро-интестинальных ГИСО (ЭГИСО) на самом деле являются диссеминированными метастазами либо вторичными но-вообразованиями, которые, вероятно, отделились от пер-вичного очага в ЖКТ в ходе опухолевого роста. Таким об-разом, истинно экстрагастроинтестинальными может считаться не более 1,5% ГИСО.…”