Septum Pellucidum Chronic Encapsulated Hematoma With Osseous Metaplasia Mimicking Recurrent Astrocytoma and Shunt-Related Foreign Body Granuloma

Abstract

We present a very rare case of chronic encapsulated intracerebral hematoma involving the septum pellucidum and the foramen of Monro that by location radiological appearance, and clinical history was mimicking a recurrent astrocytoma or a shunt-related foreign body granuloma. A young adult underwent the resection of a juvenile pilocytic astrocytoma as a child, and with a mass encasing the tip of an old non-functioning ventricular catheter, the differential diagnosis of shunt-related foreign body granuloma versus recurrent low-grade glioma was raised. Although chronic encapsulated intracerebral hematomas have been reported in the literature, the anatomical location of the lesion in the presented case was unique, with radiological and history findings also posing a peculiar diagnostic challenge. Chronic encapsulated intracerebral hematomas are benign entities that may also be found to involve deep and midline supratentorial structures usually not prone to spontaneous intraparenchymal hemorrhages. When symptomatic, surgical resection of the hematoma can be both diagnostic and curative.

Unusual vascular anatomical variant leads to spontaneous hemorrhage in a cavum septum pellucidum in an adolescent: A case report and literature review

“…[ 6 ] The nontraumatic causes in adults are exceedingly rare [ Table 1 ] and are mostly attributed to anterior cerebral artery aneurysm bleeding[ 8 , 12 ] where the blood can enter into the CSP through fenestrations formed in cavum wall and cisterna lamina terminalis,[ 3 , 10 ] venous thrombosis,[ 2 ] hypertension,[ 4 ] or tumors (particularly, subependymomas of septum pellucidum and glioblastoma of the corpus callosum which are extremely vascular and may even rebleed). [ 5 , 7 , 9 ] Other cases of spontaneous CSP bleeding were reported in premature and full-term infants as a result of ruptured over distended veins in the septal walls, residual germinal matrix, or choroid plexus bleeding. [ 6 ] Idiopathic causes without identifiable underlying lesions were also reported.…”

“…Chronic encapsulated hematomas are known to form fibrous pseudocapsule with gradual expansion due to recurrent microhemorrhages into its core, mimicking neoplastic lesions. [ 9 ] However, it is rarely reported within CSP.…”

Encapsulated Intracerebral Hematoma Presenting as Cerebral Abscess

“…CEIH remains rare, and due to its variable radiographic appearance, may be mistaken for a tumor or a brain lesion [1][2][3][4][5][6][7][8][9][10][11]. Recent case reports have shown CEIH occurrences as a late complication of AVM radiosurgery, with 37 cases described as of 2020 [5,10].…”

“…Chronic encapsulated intracerebral hematoma (CEIH) is difficult to diagnose because of its tendency to mimic other brain lesions [1][2][3][4]. Patients may develop CEIH after spontaneous intracerebral hemorrhage (ICH), and in more recent years, CEIH has been reported after radiosurgery for arteriovenous malformations (AVMs) [4][5][6][7][8][9][10][11].…”

Chronic Encapsulated Intracerebral Hematoma as an Occasional Finding in Sudden Cardiac Death

“…However, in most cases the etiology remains unknown [ 6 ]. The diagnosis is very challenging, and it is made preoperatively in approximately 20% of cases [ 1 ], especially in patients with no clinical history or when other intracranial conditions are present [ 1 , 7 ].…”