Intracranial Foreign Body Granuloma Mimicking Brain Tumor Recurrence: A Case Series.

Abstract

Intracranial foreign body granuloma (FBG) is a rare inflammatory reaction to retained foreign material, manifesting acutely or months to years following neurosurgical procedures. Radiographically, FBG can mimic tumor progression, and tissue biopsy may be required to guide management. In this retrospective case series, we present unique clinico-radiographic and histopathological features of six neuro-oncological patients diagnosed with FBG between 2007 and 2019. All six patients (4 women and 2 men, aged 29-54 [median, 30.5] years) had undergone surgical resection of a low- (n = 4) or high-grade (n = 2) glioma. FBG manifestation postsurgery ranged from 1 day to 4 years and was predominantly asymptomatic (n = 5/6). Magnetic resonance imaging universally demonstrated one or multiple peripherally enhancing lesion(s) adjacent to the resection cavity. Histopathology in all (n = 4/4) resected specimens demonstrated an inflammatory reaction to foreign material, confirming FBG. Intracranial FBG constitutes a rare but challenging treatment-related condition effectively managed by surgery, with important therapeutic implications in neuro-oncology.