Brain Granuloma: Rare Complication of a Retained Catheter

BACKGROUND: Ventriculoperitoneal (VP) shunt is the most frequent treatment for hydrocephalus. VP shunt malfunction is a very common problem in neurosurgical practice, often requiring shunt revision procedures. In some cases, complete removal of a VP shunt may present difficulties, leading the surgeon to leave the ventricular catheter in situ. This decision is often made to avoid possible adverse events, primarily risk of life-threatening hemorrhage. However, a nonfunctioning catheter left in the ventricular system may lead to further complications.CASE DESCRIPTION: We report the case of an adult man who presented with a tumor-like cystic lesion, with mural and nodular postcontrast enhancement, caused by a huge granuloma formed around the tip of a retained ventricular catheter.CONCLUSIONS: This occurrence is extremely rare, and this is the first reported case in the literature. Preoperative differential diagnosis was challenging and included infection, metastasis, dysembryogenetic lesions, and rare reversible porencephalic cysts. According to several physiopathogenetic theories recently reported in the literature, the granuloma may develop as the result of persistent chronic inflammatory reactions between the ventricular catheter left in situ and the brain parenchyma. Application of neuroendoscopic techniques is improving management of VP shunt revisions, allowing safe removal of catheters stuck or lost in the ventricular system. Neuroendoscopy may represent an additional option to avoid possible complications related to retained ventricular catheters.