Colonic inflammation in a samoan immigrant with gastric lymphoma shown by positron emission tomography.

A 57-year-old Samoan man with large B-cell gastric lymphoma presented with fatigue, anemia, and melena. A positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG) showed no gastric activity but marked hypermetabolic activity in the cecum and ascending colon (Figure 1 ). Corresponding computed tomography (CT) revealed bowel wall thickening, consistent with infectious or inflammatory process. Colonoscopy showed non-specific inflammatory changes. Laboratory work showed leukocytosis (white blood cells = 19.3) and eosinophilia (absolute eosinophil count [AEC] = 9.2). Extensive infectious disease workup was only significant for a positive Strongyloides antibody (3.11; normal < 1.5). He received two doses of ivermectin 2 weeks apart.1 Post-treatment PET/CT showed resolution of FDG uptake and normalization of bowel wall thickness (Figure 2 ). Concurrent laboratory tests confirmed resolution of the infection with negative antibodies (0.35).

Figure 1.

PET/CT 1-10-2013.

Figure 2.

PET/CT 4-05-2013.

S. sterocoralis nematodes typically inhabit the small bowel; therefore, involvement of the cecum and ascending colon in this patient suggests a hyperinfection syndrome. Diagnosis of Strongyloides may be established by detection of larvae in stool or a biopsy or by serology. PET and CT are not typically used for diagnosis. However, this case shows Strongyloides hyperinfection syndrome by PET as an incidental finding and reinforces the need to maintain a high index of suspicion for this infection in immigrants from endemic regions.