Imaging features of small bowel amyloidosis at PET/CT

Abstract

Regarding the imaging features of small bowel amyloidosis at PET/CT, we read with interest the case report by Tang et al. [1] in the December 2011 issue of Abdominal Imaging. The imaging features of intestinal amyloidosis at PET/CT have not been sufficiently investigated. Recently our group [2] described a case of diffuse intestinal amyloidosis in a patient with multiple myeloma. Although both ultrasound and MRI showed diffuse intestinal wall symmetrical thickening with increased number and hypertrophy of the folds causing ‘‘jejunalization’’ of the ileum, the PET/CT images showed neither a focal nor a diffuse increase in tracer uptake of small bowel walls. We supposed that the lack of pathological tracer uptake at PET/CT images was highly indicative of the absence of active inflammatory and/or neoplastic cells in the intestinal walls and represented a really important finding suggesting the storage nature of the disease characterized by the intramural deposition of an amorphous substance such as amyloid. In contrast, Tang et al. observed an increasing metabolism of multiple intestinal segments at PET/CT scan corresponding to the amyloid infiltration of the wall. Firstly it would be interesting to know which type of amyloidosis affected the patient. Moreover, the authors could offer an explanation to the metabolic intestinal finding at PET/CT: was the intestinal amyloid deposition accompanied by active inflammation?