Inflammatory pseudotumours resembling multiple hepatic metastases and their complete regression, as revealed by ¹⁸F-FDG PET/CT

Excerpt

An asymptomatic 66-year-old woman underwent ¹⁸F-FDG PET/CT for routine restaging. She had a 14-year history of breast cancer. On PET/CT, multiple hypermetabolic foci that were suggestive of metastases were detected in the liver (a). On abdominal CT, the foci showed peripheral rim enhancement, which was also suggestive of multiple hepatic metastases (b). However, a liver biopsy failed to detect any malignant features. Microscopically, the tumour was composed of spindle cells that resembled myofibroblasts, chronic inflammatory cells and intervening collagen deposits. These features suggested it was an inflammatory pseudotumour (IPT). Moreover, all other evaluations, including colonoscopy, duodenoscopy and chest CT, showed no evidence of primary malignancy. The patient was conservatively treated with antibiotics for 6 months. After 1 month, abdominal CT showed that the masses had shrunk. Follow-up PET/CT and dynamic abdominal CT performed after 6 months revealed that the hypermetabolic lesions and enhancing masses in the liver had vanished completely (c, d). …