PMC9162265_01
Multidetector computed tomography (MDCT) arterial-phase, sagittal plane. Focal mass in the gastric lumen, next to the cardias, characterized by enhancement comparable to that of the gastric wall. The mass is vegetating into the gastric lumen.
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F1
Given the endoscopic suspicion of gastric cancer, a multidetector CT scan was prescribed, showing a 3-cm polypoid mass in the stomach fundus, involving the cardia area (Figure 1).
Pyloric gland adenoma of the cardia. (A) The intramucosal neoplastic proliferation (on the left) is composed of closely packed glandular units. Note, on the right, the esophageal squamous epithelium (hematoxylin and eosin). (B) Focally, high-grade dysplastic features, with marked loss of nuclear polarity and complex papilary architecture, are seen (hematoxylin and eosin). (C) Neoplastic glands are diffusely immunoreactive for the pyloric gland marker MUC6 (MUC6 immunohistochemistry). (D) A superficial coating of MUC5AC-positive cells is appreciated, while the deeper glands are MUC5AC-negative (MUC5AC immunohistochemistry).
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F2
The lesion was composed of closely packed pyloric-like glands, mainly lined by columnar cells with round nuclei and inconspicuous nucleoli, and glassy-to-eosinophilic cytoplasms (Figure 2A). Focal areas of increased architectural complexity with loss of cell polarization, consistent with high-grade dysplasia, were also seen (Figure 2B). The glandular proliferation expressed MUC5AC (monoclonal, clone CLH2, Dako Omnis) in the superficial component and MUC6 (monoclonal, clone CLH5, Novocastra) (Figures 2C,D) in the deeper portion.
Fundus enterochromaffin-like (ECL) cell hyperplasia and dysplasia. (A,B) Oxyntic mucosa showing severe atrophy with extensive pseudopyloric and intestinal metaplasia. Note the presence of aggregates of closely packed micronodules in the deep lamina propria, at higher magnification in B (hematoxylin and eosin). (C) Chromogranin-A-positive ECL cell adenomatoid hyperplasia, consisting of aggregates of more than four neuroendocrine cell micronodules in the lamina propria (chromogranin-A immunohistochemistry). (D) ECL cell fused micronodules (with no intervening basal membrane), consistent with neuroendocrine cell preneoplastic/dysplastic lesions (chromogranin A immunohistochemistry).
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F3
On the contrary, the oxyntic mucosa adjacent to the PGA featured the histological hallmarks of autoimmune atrophic gastritis: severe mucosal atrophy with extensive intestinal and pseudo-pyloric metaplasia, chronic inflammation, absence of Helicobacter pylori, and linear and micronodular hyperplastic proliferations of the ECL cells (Figures 3A,B). In addition, adenomatoid hyperplasia, defined as clusters of 5 or more ECL-cell micronodules in the lower third of the mucosa (Figure 3C), as well as dysplastic ECL-cell proliferations (fused micronodules without intervening basal membrane) were identified (Figure 3D).