Intracranial foreign material granulomas after cranial surgery

Area of Science:

• Neurosurgery
• Pathology
• Oncology

Background:

• Synthetic materials are frequently used in neurosurgery for hemostasis, dural closure, and cranioplasty.
• While generally safe, these materials can lead to foreign body granulomas months or years post-intracranial surgery.
• Little is known about the treatment and outcomes of these delayed intracranial lesions.

Purpose of the Study:

• To investigate the characteristics, treatment, and outcomes of foreign body granulomas.
• To identify the types of synthetic materials implicated in foreign body granuloma formation.
• To assess the prognosis following surgical intervention for these lesions.

Main Methods:

• A systematic review of 3466 histopathological examinations post-cranial surgery.
• Identification and analysis of 12 patients with foreign body granulomas from synthetic materials, excluding Teflon granulomas and infections.
• Review of patient records, imaging, histopathology, and postoperative outcomes.

Main Results:

• The median time between surgeries was 13 months; 75% of patients presented with symptoms.
• Oxidized cellulose polymer, suture material, Gelfoam, methylmethacrylate, and bone wax were identified as causative agents.
• All 12 patients underwent complete granuloma resection with symptomatic improvement and no recurrence on imaging.

Conclusions:

• Foreign body granulomas are rare but important differential diagnoses for intracranial mass lesions, particularly after prior surgery.
• Further research is needed to clarify the pathogenesis of foreign body granulomas.
• Surgical removal of foreign body granulomas results in a good prognosis and symptomatic relief.