Diagnostic accuracy of stereomicroscopy assessment of invasion depth in ex vivo specimens of early gastric cancer

Figure 3 Workflow for preoperative assessment and postoperative management of stereomicroscopy-confirmed submucosal lesions pathologically diagnosed as submucosal. A: White light imaging of a 0-IIa + IIc lesion located on the posterior wall of the proximal gastric body, exhibiting a central depression; B: Stereomicroscopic evaluation of the specimen after 24-hour formalin fixation; C: High-magnification stereomicroscopy of the central depressed area after eosin staining, demonstrating irregular microsurface patterns; D: Stereomicroscopic overview of the basal surface of the specimen; E: Medium-magnification stereomicroscopy of the basal surface, revealing a thickened submucosal layer with a yellowish-white discoloration; F: High-magnification stereomicroscopy of the basal surface, showing loss of submucosal connective tissue architecture, indicative of tumor invasion into the submucosa; G: The initial incision of the specimen was performed at a distance from the suspected submucosal invasion site on the basal surface to avoid disrupting the area of interest; H: The specimen was inverted to expose the mucosal surface, followed by systematic sampling at 2-mm to 3-mm intervals; I: Lateral view highlighting the deepest point of submucosal invasion; J: Histopathological images confirming the submucosal diagnosis and margin status.