PMC4929359_01
Abdominal pelvis CT scan. a Initial CT scan showing dilated appendix with hypoenhancing wall (arrow) and minimal surrounding fat stranding. There were no drainable fluid collections. b Repeat CT scan 3 days later showing dilated appendix with hypoenhancing wall (arrow), now with an adjacent loop of small bowel with thickened wall (arrowhead). There remained no drainable fluid collections, no free fluid, and no free air.
crg-0010-0081-g01.jpg
PMC4929359_01_crg-0010-0081-g01.jpg
F1
There were no drainable fluid collections (fig. 1a). There remained no extraluminal air or drainable fluid collections to suggest perforation (fig. 1b).
Ileocecectomy specimen. The appendix was completely necrotic (arrowhead) as was a segment of ileum that was in direct contact with the appendix (arrows).
crg-0010-0081-g02.jpg
PMC4929359_01_crg-0010-0081-g02.jpg
F2
The necrotic appendix was lying on top of an adjacent loop of terminal ileum that was also segmentally necrotic at the contacting surface (fig. 2).
Microscopic examination of the ileocecectomy specimen. a H&E-stained section shows thrombosed vessels (arrows) and ischemic changes associated with hemorrhage (arrowheads). x4. b H&E-stained section of a vessel filled with hyphae in a patient with neutropenia. Inflammatory cells are largely absent. Pale-staining hyphae that do not stain well with H&E often look like bubbles or holes in the tissue. x40. c GMS-stained section of a vessel containing fungal hyphae that also involve adjacent submucosa. Characteristic wide ribbon-like aseptate hyphae with broad-angle branching are seen (arrows). x40. d GMS-stained section of fungal hyphae (arrows) in the muscularis propria of the appendix. x40.
crg-0010-0081-g03.jpg
PMC4929359_01_crg-0010-0081-g03.jpg
F3
Hematoxylin and eosin (H&E)-stained sections showed ischemic changes, hemorrhage, and thrombosed vessels filled with broad irregular aseptate hyphae (fig. 3a, b). Gomori methenamine silver (GMS)-stained sections also demonstrated characteristic wide ribbon-like aseptate hyphae that branch at wide angles, typical of Zygomycetes, involving both vessels and adjacent submucosa (fig. 3C) as well as invading through the muscularis propria of the appendix (fig. 3D).