Fig. 1

Endoscopy revealed that hundreds of small nodules distributed in esophagus (a), terminal ileum (b), and colon (c). Histologically, several small round nodules located in the submucosa. Most nodules were composed of a large number of collagen and scarce stellate tumor cells (d: H&E × 200, e:H&E × 400). In some nodules, tumor cells were abundant (f: H&E × 200). The tumor cells showed positive for vim (g), and negative for h-CALD (h, the smooth muscle of muscularis mucosae was positive), CD34 (i, the vascular endothelium was positive). The lesions were blue with Masson Trichrome stain (j, the smooth muscle of muscularis mucosae was stained red), red with PAS stain (k), and pink with Congo red stain (l)