Histopathological Assessment of the Endoscopic Resection Specimen

Abstract

Background: Endoscopic resection for early neoplastic lesions of the gastrointestinal tract is nowadays the accepted and feasible method also in non-tertiary reference centers. The main clinical advantage is the preserved quality of life compared to larger surgical procedures.

Summary: Clinical colleagues need to have basic knowledge of factors that may influence the outcome of histopathology. This article discusses issues connected to the histopathological work-up of endoscopic resection specimens within in the gastrointestinal tract.

Key messages: Besides the clinical technical prerequisites, standardized histopathology is the key element of the pathology laboratory work-up of endoscopic resection specimens. Overdiagnoses of reactive lesions as low-grade neoplasia lead to incomparable study data and although criteria to overcome this situation exist, they are not accepted worldwide, calling for further efforts in harmonization.

Keywords: Endoscopic resection; Issues; Pathology; Quality.

Fig. 1.

Expression of mucins (MUC5AC, MUC6, MUC2) and CD10, modified after [5]. Scoring: negative = 0–4%, activity 1+ = 5–30%, 2+ = 31–60%, 3+ >60%. Some tumors show a complete gastric phenotype (blue box) or complete intestinal (green box). A small proportion shows a NOS type (gray box). Mixed types occur (lower right) and those can be predominantly gastric or intestinal (lower left or upper right of the gray boxes). Gray boxes indicate tumors that show the same amount of gastric and intestinal markers. Those range from grade 1 (minimal) to grade 6 (co-expression). Notably, with higher grades gastric differentiation is more frequent, especially in the stomach. In routine histopathology work-up, auxiliary immunohistochemical analyses are not to be recommended since clinical relevance of those different differentiations is missing.