Fig. 1

Endoscopic and morphological findings of the patient with systemic mastocytosis. A Colonoscopy showing a 3.0 cm × 3.0 cm protuberant lesion in the cecum with erosion, necrosis, and ulcer formation on the surface. B Biopsy specimen of the intestinal lesion depicted in (A), showing expanded lamina propria by medium-sized mast cells (hematoxylin and eosin stain, × 40 magnification). C Round/oval mast cells with a mixture of eosinophil cells (hematoxylin and eosin stain, × 100 magnification). D Atypical mast cells with abundant eosinophilic cytoplasm and hyperchromatic nucleus (hematoxylin and eosin stain, × 400 magnification)