Contributed by Amber Henry, MD and Shih-Fan Kuan, MD
The patient is 35-year-old previously healthy native African male, who moved to the United States two years ago. He presented to an outside facility with a chief complaint of anal and rectal bleeding. Laboratory values are unremarkable, and include: hemoglobin 13.1 gm/dL, hematocrit 39%, white blood cell count 6,000 cell/cc, eosinophils 2.9% (normal 0.2-6.0%), platelets 224, calcium 9.2 mg/dL, albumin 3.7 g/dL, glucose 94 mg/dL, AST 51 IU/L, ALT 45 IU/L, alkaline phosphatase 47 IU/L, total bilirubin 0.5 mg/dL, sodium 135 mmol/L, potassium 4 mmol/L, chloride 110 mmol/L, blood urea nitrogen 9 mg/dL, and creatinine 1.1 mg/dL. Colonoscopy revealed thrombosed external hemorrhoids and mild erythema in the rectal area. There were also small, non-bleeding internal hemorrhoids. The terminal ileum appeared normal. Clinically, the differential diagnosis included colonoscopy preparation-related changes and a mild colitis. The colonoscopy findings were sufficient to explain mild hematochezia, and fiber supplementation with repeat screening colonoscopy in ten years was recommended.
Pathology received five minute fragments of tissue in formalin, ranging in size from 0.1 to 0.3 cm. These pieces were entirely submitted. Histology reveals colitis with prominent eosinophils. The eosinophilic reaction is most pronounced in one fragment of tissue, surrounding two unusual foreign bodies within the lamina propria (Figures 1, 2, 3, and 4). These appear to be within vascular spaces, and are highlighted by PAS/PAS-D stains (Figure 5) and Grocott stain (Figure 6). Immunohistochemical stains for cytomegalovirus and herpes simplex virus are negative.