Clinicopathological study on chronic encapsulated expanding hematoma associated with incompletely obliterated AVM after stereotactic radiosurgery

Natural History and Histopathology of Expanding Cysts and Hematomas After Stereotactic Radiosurgery for Arteriovenous Malformations of the Brain: A Case Series

BACKGROUND

We reviewed the clinical course and histopathologic findings for cases involving the formation of expanding cysts and/or hematomas after gamma knife surgery (GKS) for arteriovenous malformations (AVMs).

METHODS

We report a single-center retrospective review of 18 patients who presented with cyst and/or hematoma expansion after GKS for AVMs between 1993 and 2023. Expanding cysts and hematomas were defined as well-demarcated cavities filled with fluid or well-marginated heterogenous hematomas presenting with expansion proximal to or in the location of the original AVM, respectively. Patient demographics, AVM characteristics, history of interventions and surgeries, and imaging and histopathologic features of expanding cysts and hematomas were collected for analysis.

RESULTS

Among 1072 AVM patients treated using GKS, 18 presented with expanding cysts or hematomas during a total follow-up period of 16,757 patient-years (0.11 case/100 persons/patient-year). The time to cyst or hematoma identification was 4-13 years after initial GKS, with a mean duration of 8.6 years. Among the patients examined, 7 (38.9%) presented mainly with hematoma, 10 (55.6%) presented mainly with cysts, and 1 presented with approximately equal components of both. Among the 18 patients, 13 (72.2%) underwent craniotomy to treat cyst or hematoma expansion. All the specimens had similar histopathologic characteristics, including organizing hematoma with fresh and old hemorrhage, fibrinoid necrosis of the vessels, gliosis of normal brain tissue, infiltration of hemosiderin-laden histiocytes, and extravascular protein leakage.

CONCLUSIONS

Our findings suggest that the formation of these 2 complications can be attributed to a common mechanism involving radiation-induced vascular damage in brain tissue adjacent to the AVM and subsequent chronic inflammation and capillary dilatation.

Chronic encapsulated intracerebral hematomas: a systematic review

BACKGROUND

Chronic encapsulated intracerebral hematoma (CEICH) is a rare type of intracerebral hematoma (ICH) with peculiar radiological features and presenting as subtle slow-growing lesion exerting mass effect. We performed a systematic review of the literature focused on diagnosis and management of patients affected by CEICH.

MATERIAL AND METHODS

A literature search according to the PRISMA statement was conducted using PubMed and Scopus databases and pertinent Mesh terms. All papers that reported intraventricular CEICH, or CEICH cases treated conservatively or by CT-guided needle aspiration were not included in this study. A total of 40 papers were included in this review, with 58 patients (38 males and 20 females) and a mean age of 41.44 ± 20.05 years (range 1-80).

RESULTS

Neurological symptoms of onset include those related to an increase in intracranial pressure (ICP) in 28/58 cases (48.2%), seizures in 17/58 cases (29.3%), motor deficits in 14/58 cases (24.1%). The most frequent localization is atypical in 45/58 cases (77.6%). Surgical approach is not specified in 21/58 cases (36.2%), craniotomy was performed in 31/58 cases (53.4%), craniectomy in 5/58 cases (8.6%) and only in one case (1.7%) an endoscopic approach was performed. CEICH are usually located in an atypical site.

CONCLUSIONS

There is not an association with anticoagulants and antiplatelets intake. Arteriovenous malformation is the most frequent cause. Surgery is suggested, and craniotomy is the most used approach even if further investigation should be directed to analyze the efficacy of endoscopic approach of these lesions, which may show favorable outcome.

Chronic Encapsulated Expanding Hematomas After Stereotactic Radiosurgery for Intracranial Arteriovenous Malformations: An International Multicenter Case Series

BACKGROUND

Stereotactic radiosurgery (SRS) offers a minimally invasive treatment modality for appropriately selected intracranial arteriovenous malformations (AVMs). Recent reports have described the development of rare, delayed chronic encapsulated expanding hematomas (CEEHs) at the site of an angiographically confirmed obliterated AVM.

OBJECTIVE

To elucidate the incidence, characteristics, and management of CEEH in patients with AVM after SRS.

METHODS

The records of all patients who underwent SRS for an intracranial AVM at 4 institutions participating in the International Radiosurgery Research Foundation between 1987 and 2021 were retrospectively reviewed. Data regarding characteristics of the AVM, SRS treatment parameters, CEEH presentation, management, and outcomes were collected and analyzed.

RESULTS

Among 5430 patients, 15 developed a CEEH at a crude incidence of 0.28%. Nine patients were female, and the mean age was 43 ± 14.6 years. Nine patients underwent surgical evacuation, while 6 were managed conservatively. The median CEEH development latency was 106 months after SRS. The patients were followed for a median of 32 months, and 9 patients improved clinically, while 6 patients remained stable. No intraoperative complications were reported after CEEH resection, although 1 patient recovered from postoperative meningitis requiring intravenous antibiotics.

CONCLUSION

CEEH is a rare, late complication of AVM SRS with an incidence of 0.28% and a median latency of 106 months. In the presence of a delayed and symptomatic expanding hematoma in the bed of an angiographically obliterated AVM, surgical resection resulted in clinical improvement in most patients. Conservative management is possible in asymptomatic patients with stable, small-sized hematomas in deeply seated locations.

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

Chronic encapsulated intracerebral hematoma (CEIH) is a rare solid mass characterized by the presence of a fibrotic capsule that can present a variety of signs and symptoms due to the mass effect and hydrocephalus. It may be caused by post-traumatic or spontaneous bleeding as related to an adjacent aneurysm, angiomas or neoplasms. Differential diagnosis must be applied in order for it to mimic neoplasm or a vascular malformation. Several cases of CEIH have been reported but only a few of them have an intraventricular localization. A forensic autopsy of a 50-year-old male who died suddenly while driving is discussed. Gross analysis, histology and toxicology were performed and a CEIH of the right lateral ventricle was found in a case of acute coronary death.

Hemorrhage and Recurrence of Obliterated Brain Arteriovenous Malformations Treated With Stereotactic Radiosurgery

BACKGROUND

Although complete nidal obliteration of brain arteriovenous malformations (AVM) is generally presumed to represent durable cure, postobliteration hemorrhage, and AVM recurrence have become increasingly recognized phenomena. The goal of the study was to define hemorrhage and nidal recurrence risks of obliterated AVMs treated with stereotactic radiosurgery (SRS).

METHODS

This is a retrospective cohort study from the International Radiosurgery Research Foundation comprising AVM patients treated between 1987 and 2020. Patients with AVM obliteration on digital subtraction angiography (DSA) were included. Outcomes were (1) hemorrhage and (2) AVM recurrence. Follow-up duration began at the time of AVM obliteration and was censored at subsequent hemorrhage, AVM recurrence, additional AVM treatment, or loss to follow-up. Annualized risk and survival analyses were performed. A sensitivity analysis comprising patients with AVM obliteration on magnetic resonance imaging or DSA was also performed for postobliteration hemorrhage.

RESULTS

The study cohort comprised 1632 SRS-treated patients with AVM obliteration on DSA. Pediatric patients comprised 15% of the cohort, and 42% of AVMs were previously ruptured. The mean imaging follow-up after AVM obliteration was 22 months. Among 1607 patients with DSA-confirmed AVM obliteration, 16 hemorrhages (1.0%) occurred over 2223 patient-years of follow-up (0.72%/y). Of the 1543 patients with DSA-confirmed AVM obliteration, 5 AVM recurrences (0.32%) occurred over 2071 patient-years of follow-up (0.24%/y). Of the 16 patients with postobliteration hemorrhage, AVM recurrence was identified in 2 (12.5%). In the sensitivity analysis comprising 1939 patients with post-SRS AVM obliteration on magnetic resonance imaging or DSA, 16 hemorrhages (0.83%) occurred over 2560 patient-years of follow-up (0.63%/y).

CONCLUSIONS

Intracranial hemorrhage and recurrent arteriovenous shunting after complete nidal obliteration are rare in AVM patients treated with SRS, and each phenomenon harbors an annual risk of <1%. Although routine postobliteration DSA cannot be recommended to SRS-treated AVM patients, long-term neuroimaging may be advisable in these patients.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

Chronic encapsulated expanding hematomas after stereotactic radiosurgery for intracranial arteriovenous malformations

OBJECTIVE

Cerebral arteriovenous malformations (AVMs) are rare cerebral vascular lesions that are associated with high morbidity and mortality from hemorrhage; however, stereotactic radiosurgery (SRS) is a well-validated treatment modality. Few reports have delineated a subgroup of patients who develop delayed chronic encapsulated expanding hematomas (CEEHs) despite angiographic evidence of AVM obliteration following radiosurgery. In this report, the authors performed a retrospective review of more than 1000 radiosurgically treated intracranial AVM cases to delineate the incidence and management of this rare entity.

METHODS

Between 1988 and 2019, 1010 patients with intracranial AVM underwent Gamma Knife SRS at the University of Pittsburgh Medical Center. In addition to a review of a prospective institutional database, the authors performed a retrospective chart review of the departmental AVM database to specifically identify patients with CEEH. Pertinent clinical and radiological characteristics as well as patient outcomes were recorded and analyzed.

RESULTS

Nine hundred fifty patients with intracranial AVM (94%) had sufficient clinical follow-up for analysis. Of these, 6 patients with CEEH underwent delayed resection (incidence rate of 0.0045 event per person-year). These patients included 4 males and 2 females with a mean age of 45.3 ± 13.8 years at the time of initial SRS. Four patients had smaller AVM volumes (4.9-10 cm3), and 3 of them were treated with a single SRS procedure. Two patients had larger-volume AVMs (55 and 56 cm3), and both underwent multimodal management that included staged SRS and embolization. Time to initial recognition of the CEEH after initial SRS ranged between 66 and 243 months. The time between CEEH recognition and resection ranged from 2 to 9 months. Resection was required because of progressive neurological symptoms that correlated with imaging evidence of gradual hematoma expansion. All 6 patients had angiographically confirmed obliteration of their AVM. Pathology revealed a mixed chronicity hematoma with areas of fibrosed blood vessels and rare areas of neovascularization with immature blood vessels but no evidence of a persistent AVM. All 6 patients reported persistent clinical improvement after hematoma resection.

CONCLUSIONS

CEEH after SRS for AVM is a rare complication with an incidence rate of 0.0045 event per person-year over the authors' 30-year experience. When clinical symptoms progress and imaging reveals progressive enlargement over time, complete resection of a CEEH results in significant clinical recovery. Knowledge of this rare entity facilitates timely detection and eventual surgical intervention to achieve optimal outcomes.

Results of surgical treatment after Gamma Knife radiosurgery for cerebral arteriovenous malformations: patient series

BACKGROUND

Gamma Knife radiosurgery (GKRS) is a safe and effective treatment, but it has a risk of bleeding. Herein, the authors describe their experience with some patients who required surgical removal of cerebral arteriovenous malformations (AVMs) located mainly in eloquent areas of the brain after GKRS, and they consider the advantages of surgical removal after GKRS.

OBSERVATIONS

Twelve patients who had undergone surgical removal of AVMs after GKRS at Tokyo Women’s Medical University between April 2013 and July 2019 were selected for analysis. All participants underwent GKRS as first-line therapy for AVMs located in an eloquent region or if requested by the patient. Complete obliteration was achieved in 7 patients, and the size of the nidus decreased in 3 patients during the follow-up period. The Spetzler-Martin grade decreased in 11 patients. Three patients experienced symptomatic intracerebral hemorrhage before and after confirmation of complete obliteration of the nidus via GKRS, and 7 patients experienced some neurological deficits because of an encapsulated expanding hematoma. All patients underwent resection of the nidus without complications. The preoperative neurological deficits improved in 6 patients and remained unchanged in 6 patients.

LESSONS

This report indicates that performing GKRS before surgery may be useful for future multimodal therapy.

A chronic encapsulated expanding hematoma that developed 15 years after gamma knife surgery for a cerebral arteriovenous malformation: A case report and review of the literature

We report a case of gamma knife surgery (GKS)-induced chronic encapsulated expanding hematoma with extensive literature review. A 17-year-old young man underwent GKS after embolization for arteriovenous malformation (AVM) in the right frontal lobe and the AVM completely disappeared. He developed a generalized convulsion 15 years after GKS. MRI showed a small oedematous change at the AVM site. His epileptic seizure was controlled with anticonvulsant. His epilepsy recurred after three years, and MRI revealed an intracerebral hematoma with extensive surrounding edema at the same lesion. He underwent cerebral angiography and a recurrence of AVM was prevented. The hematoma was surgically removed, and intraoperative finding confirmed an old hematoma with a capsule and capillary hyperplasia, without developing cavernous angioma. The final diagnosis was a secondary chronic encapsulated expanding hematoma after GKS. This is the first report to show the early-stage imaging findings of this late effect after GKS.

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

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 supra-tentorial structures usually not prone to spontaneous intraparenchymal hemorrhages. When symptomatic, surgical resection of the hematoma can be both diagnostic and curative.

Late complications of radiosurgery for cerebral arteriovenous malformations: report of 5 cases of chronic encapsulated intracerebral hematomas and review of the literature

Background

Chronic encapsulated intracerebral hematomas (CEIHs) are a rare, late complication of radiosurgery for intracranial AVM. We present 5 cases treated mostly by surgical excision and review the literature.

Methods

Patients (age 39, 42, 36, 31, 62) presented with headache, paresthesia, hemiparesis or were asymptomatic. CEIHs presented 10 to 13 years (median 12 years) post radiosurgery. Three patients had demonstrated early radiation induced changes post radiosurgery. Angiographic cure, assessed with DSA, was present in all cases except 1 case with a small nidus remnant. MRI demonstrated mixed lesions with a solid enhancing part, organized hematoma and extensive surrounding edema while three cases had also a cystic component.

Results

Excision of the CEIHs with complete or partial removal of the capsule was performed in 4 patients and resulted in marked clinical improvement. One patient was managed conservatively with administration of steroids as surgery was judged excessively hazardous with eventual stabilization of his symptoms.

Conclusions

CEIHs are rare, late complications of radiosurgery for cranial AVM. They may be asymptomatic or provoke symptoms and may be preceded by early radiation induced changes. Complete removal of CEIHS is an effective treatment. Because of the long latency period of CEIHs, patients who had radiosurgery for brain AVMs should be followed by MRI at least 10 years even after complete obliteration.

Do Direct Bypasses Really Resolve Capillary Vessels in Moyamoya Disease? Delayed Hemorrhage Potentially Relevant to Direct Bypasses: A Pathological Investigation

OBJECTIVE

Moyamoya disease is a chronic but progressive obliterative cerebrovascular disease of bilateral internal carotid arteries (ICAs) causing hemorrhagic or ischemic cerebral strokes. Surgical revascularization has the potential for resolving the capillary vessels, but the effect on the occlusive ICA and the moyamoya vessels after a direct bypass remains unclear.

PATIENT

A 2-year-old girl with a history of repeated transient ischemic attacks and direct bypasses but demonstrating improvement and associated anomaly is reported. A year and a half later, after a bilateral revascularization, an intracerebral capsulized hematoma growth was identified, and it was removed surgically. Neovascularization including many microvessels similar to capillary telangiectasia were identified by pathological investigation despite the reduction of moyamoya vessels on the repeated angiograms after the revascularization surgeries. In the present case, proliferation of capillary vessels was clearly confirmed by direct bypasses.

CONCLUSION

There is no doubt that direct bypasses prevent further ischemic stroke by improving cerebral blood flow. However, they may result in failure in reducing the load of moyamoya vessels, albeit decreasing the potential risk of hemorrhagic strokes.

Chronic encapsulated expanding hematoma after stereotactic radiosurgery of cerebral arteriovenous malformation

Stereotactic radiosurgery has become excellent alternative treatment for cerebral arteriovenous malformations (AVM). This technique has expanded to treatment of larger AVM which is not amenable to surgical management. However, its variable adverse effects should be also taken into considerations sincerely because of radiobiological characteristics such as delayed onset and progressive neurological deteriorations. Herein, we report a case in which progressively expanding hemorrhagic cyst with repeated bleedings so called chronic encapsulated expanding hematoma was developed on several years after radiosurgery treatment. Neurological and radiological findings were improved by surgical removal.

Chronic encapsulated intraventricular hematoma in a pediatric patient: case report

Chronic encapsulated intraventricular hematoma (CEIVH) is a rare, intraventricular, nonneoplastic mass lesion that can become symptomatic from mass effect or obstructive hydrocephalus. Only 5 cases have been reported in the literature, and only one of these occurred in a pediatric patient and dates back to the pre-modern neuroimaging and pre-microsurgical era of neurosurgery. Imaging features can mimic those of many more common intraventricular lesions, such as choroid plexus tumors or cavernous malformations. In all reported symptomatic cases, resection was safely performed and led to a cure and symptom resolution. Here, the authors present a case of CEIVH in a pediatric patient, describe the operative techniques of resection, review the available literature, and discuss current understanding of the pathophysiology, making this the most comprehensive report on this disease entity to date. The case is a 14-year-old boy who presented with headaches and emesis. Computed tomography showed a hyperdense mass in the trigone of the right lateral ventricle. Magnetic resonance imaging showed a contrast-enhancing well-circumscribed mass. Right temporal craniotomy utilizing a posterior middle temporal gyrus transcortical approach was performed, and gross-total resection was achieved. Pathology revealed a CEIVH. The boy's postoperative course was uncomplicated, and he was discharged 2 days after surgery.

Comparison of the Long-term Efficacy and Safety of Gamma Knife Radiosurgery for Arteriovenous Malformations in Pediatric and Adult Patients

It is debated whether the efficacy and long-term safety of gamma knife radiosurgery (GKRS) for arteriovenous malformations (AVMs) differs between adult and pediatric patients. We aimed to clarify the long-term outcomes of GKRS in pediatric patients and how they compare to those in adult patients. We collected data for 736 consecutive patients with AVMs treated with GKRS between 1990 and 2014 and divided the patients into pediatric (age < 20 years, n = 144) and adult (age ≥ 20 years, n = 592) cohorts. The mean follow-up period in the pediatric cohort was 130 months. Compared to the adult patients, the pediatric patients were significantly more likely to have a history of hemorrhage (P < 0.001). The actuarial rates of post-GKRS nidus obliteration in the pediatric cohort were 36%, 60%, and 87% at 2, 3, and 6 years, respectively. Nidus obliteration occurred earlier in the pediatric cohort than in the adult cohort (P = 0.015). The actuarial rates of post-GKRS hemorrhage in the pediatric cohort were 0.7%, 2.5%, and 2.5% at 1, 5, and 10 years, respectively. Post-GKRS hemorrhage was marginally less common in the pediatric cohort than in the adult cohort (P = 0.056). Cyst formation/encapsulated hematoma were detected in seven pediatric patients (4.9%) at a median post-GKRS timepoint of 111 months, which was not significantly different from the rate in the adult cohort. Compared to adult patients, pediatric patients experience earlier therapeutic effects from GKRS for AVMs, and this improves long-term outcomes.

Imaging Diagnosis of Chronic Encapsulated Intracerebral Hematoma, a Comparison of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) characteristics

Background

Chronic encapsulated intracerebral hematoma (CEICH) is a rare type of intracerebral hematoma that is often misdiagnosed.To explore the characteristics of CEICH on computerized tomography (CT) and magnetic resonance imaging (MRI).

Material/Methods

Clinical, CT, MRI, and susceptibility weighted imaging (SWI) data of 5 patients who were diagnosed with CEICH on surgery and pathology were retrospectively analyzed.

Results

CT showed quasi-circular or elliptical lesions with clear borders in all 5 cases and iso-density or low-density in the center of lesions that were surrounded by peripheral edema in 2 cases. CT showed mass effect in 5 patients. On contrast-enhanced CT, 2 cases exhibited mild ring enhancement, and 3 cases exhibited moderate ring enhancement. MRI showed cystic lesions with high uniform signal on T1-weighted images (T1WI) and T2-weighted images (T2WI), a lowsignal ring sign on the coated cystic lesions on T2WI, a lower signal ring sign on SWI, and ring enhancement after administration of contrast.

Conclusions

CT imaging of CEICH did not reveal any typical characteristics in the studied patients. MRI showed an envelope with a "ring" and intra-capsular bleeding features. MRI is an effective imaging modality for the diagnosis of CEICH.

Bizarre soft tissue tumour on the gluteus muscle: a case report of spontaneous chronic expanding haematoma

Chronic expanding haematoma (CEH) is rare and refers to a gradually increasing haematoma that is not absorbed after surgery and trauma. This report highlights unusual mass occurring on the gluteus muscle, and the aim is to indicate the diagnostic method. It is necessary to consider the mechanism of the occurrence and to know the characters of CEH. The patient was a 51-year-old man who had noticed a soft mass on his right hip. The mass had gradually increased to 10 cm in size over the year. CT images revealed a haematoma. However, MRI showed a rare biphasic fluid-fluid layer inside the mass and indicated a different pattern compared with that of a normal haematoma. Because the mass was affecting the patient's social life, and the diagnosis was difficult to confirm, surgical treatment was elected. Intraoperatively, the mass contained a large amount of a brown mud-like substance and showed the bizarre appearance inside. The mass was diagnosed as CEH based on both the clinical findings and the histopathological diagnosis. The patient had no traumatic event and no previous surgery. In the absence of the clinical history and the unique imaging findings, it was difficult to diagnose the mass as CEH. It is important to clarify a patient's underlying disease, history, and lifestyle and to consider any correlation between the mass location and the patient's condition carefully. Considering the character of the mass and the lack of a preoperative definitive diagnosis, we recommend performing complete surgical resection.

A chronic encapsulated intracerebral hematoma mimicking a brain tumor: Findings on arterial spin labeling of MRI

BACKGROUND

Intracerebral hematoma usually resolves spontaneously. Chronic encapsulated intracerebral hematoma is rare and mimics a brain tumor.

CASE DESCRIPTION

A 50-year-old man had developed intracerebral hematoma in the right temporal lobe. Computed tomography (CT) showed the gradually decreasing density of the hematoma. However, the hematoma did not decrease in size and it showed ring enhancement on contrast-enhanced CT for more than 1 year. Magnetic resonance imaging (MRI) revealed a lesion content showing a high intensity on both T1- and T2-weighted images with ring enhancement. The lesion was diagnosed as a chronic encapsulated intracerebral hematoma developing from an acute hematoma. Arterial spin labeling of MRI showed decreased blood perfusion even in the enhanced capsule, being different from findings of a cystic brain tumor.

CONCLUSION

Arterial spin labeling might be a useful modality to distinguish a chronic encapsulated intracerebral hematoma from a cystic hypervascular brain tumor.

Chronic Encapsulated Expanding Thalamic Hematoma Associated with Obstructive Hydrocephalus following Radiosurgery for a Cerebral Arteriovenous Malformation: A Case Report and Literature Review

Chronic encapsulated intracerebral hematoma is a unique type of intracerebral hematoma accompanied by a capsule that is abundant in fragile microvasculature occasionally causing delayed regrowth. A 37-year-old man who had undergone radiosurgery for an arteriovenous malformation (AVM) causing intracerebral hematoma in the left parietal lobe presented with headache, vomiting, and progressive truncal ataxia due to a cystic lesion that had been noted in the left thalamus, leading to progressive obstructive hydrocephalus. He underwent left frontal craniotomy via a transsylvian fissure approach, and the serous hematoma was aspirated. The hematoma capsule was easy to drain and was partially removed. Pathological findings demonstrated angiomatous fibroblastic granulation tissue with extensive macrophage invasion. The concentration of vascular endothelial growth factor (VEGF) was high in the hematoma (12012 pg/mL). The etiology and pathogenesis of encapsulated hematoma are unclear, but the gross appearance and pathological findings are similar to those of chronic subdural hematoma. Based on the high concentration of VEGF in the hematoma, expansion of the encapsulated hematoma might have been caused by the promotion of vascular permeability of newly formed microvasculature in the capsule.

Growing Organized Hematomas Following Gamma Knife Radiosurgery for Cerebral Arteriovenous Malformation : Five Cases of Surgical Excision

Organized hematoma is a rare complication that can develop following gamma knife radiosurgery (GKS) for cerebral arteriovenous malformation (AVM). Here, we describe 5 patients with growing organized hematomas that developed from completely obliterated AVMs several years after GKS. The patients were 15, 16, 30, 36, and 38 years old at the time of GKS, respectively, and 3 patients were female. Four AVMs were located in the lobe of the brain, and the remaining AVM were in the thalamus. Between 2-12 years after GKS, patients developed progressive symptoms such intractable headache or hemiparesis and enhancing mass lesions were identified. Follow-up visits revealed the slow expansion of the hematomas and surrounding edema. Steroids were ineffective, and thus surgery was performed. Histology revealed organized hematomas with a capsule, but there was no evidence of residual AVMs or vascular malformation. After surgery, the neurological symptoms of all patients improved and the surrounding edema resolved. However, the hematoma continued to expand and intraventricular hemorrhage developed in 1 patient whose hematoma was only partially removed. GKS for cerebral AVM can be complicated by growing, organized hematomas that develop after complete obliteration. Growing hematomas should be surgically evacuated if they are symptomatic. Radical resection of the hematoma capsule is also strongly recommended.

Pathological characteristics of cyst formation following gamma knife surgery for arteriovenous malformation

BACKGROUND

The pathological characteristics of cyst development after gamma knife surgery (GKS) for arteriovenous malformation (AVM) were analysed.

METHOD

Sixteen male and 12 female patients aged 17-67 years (mean 31.3 years) were retrospectively identified among 868 patients who underwent GKS for AVM at our hospital. The pathological characteristics of the reddish nodular lesion and chronic encapsulated expanding haematoma associated with cyst following GKS for AVM were examined.

RESULTS

Cyst was associated with chronic encapsulated expanding haematoma in 13, and with nodular lesion in 12 patients. The nidus volume at GKS was 0.1-36 ml (median 6.0 ml), and the prescription dose at the nidus margin was 18-25 Gy (median 20 Gy). Cyst formation was detected from 1.1 to 16 years (mean 7.3 years) after GKS. Seven of the 12 patients with nodular lesion underwent surgery. Ten of the 13 patients with expanding haematoma underwent surgical removal of expanding haematoma. Histological examination was possible in 17 cases. Dilated capillary vessels with wall damage such as hyalinisation and fibrinoid necrosis, marked protein exudation and haemorrhage were the most common findings. Brain parenchyma was observed among the dilated vessels in some cases. Structureless necrotic tissue was not evident.

CONCLUSIONS

The present study suggests that enhanced nodular lesion on magnetic resonance imaging and chronic encapsulated expanding haematoma associated with cyst may have common aetiopathology caused by late radiation effects, mainly consisting of dilated capillary vessels with wall damage. Massive protein exudation from such damaged capillary vessels is important in cyst development.

Progression of cerebellar chronic encapsulated expanding hematoma during late pregnancy after gamma knife radiosurgery for arteriovenous malformation

Background:

The etiology and appropriate management strategy of chronic encapsulated expanding hematoma during pregnancy after gamma knife radiosurgery for arteriovenous malformation (AVM) remain unclear.

Case Description:

A 34-year-old female developed chronic encapsulated expanding hematoma during late pregnancy, after angiographic disappearance of cerebellar AVM following two courses of gamma knife radiosurgery. The present case implicates pregnancy as a potential promoter of growth and enlargement of chronic encapsulated expanding hematoma, which may become life-threatening and require surgical intervention.

Conclusion:

Immediate surgical management after delivery may be associated with a favorable outcome, so close follow-up management and patient education are very important in women planning pregnancy.

Abdominal Chronic Expanding Hematoma Causing Iron-Deficiency Anemia in a Dog

A 2 yr old spayed female mixed-breed Irish wolfhound was referred for assessment of anemia and slowly progressing abdominal distention. At the time of admission, the dog had marked anemia and thrombocytosis, a decreased serum iron concentration, and a normal coagulation profile. An ultrasound examination showed a massive fluid-filled cavitated structure in the abdominal cavity. Paracentesis of that structure yielded a large amount of hemorrhagic fluid with an iron concentration &gt;24 times greater than the serum iron concentration, consistent with chronic sequestration of iron, leading to iron-deficiency anemia. Blood transfusions and incomplete surgical removal of the structure allowed short-term stabilization of the patient, but the dog was euthanized 17 days postsurgery for lethargy and continued abdominal distention. Histopathological evaluation of the structure was consistent with a chronic expanding hematoma. To the authors’ knowledge, this is the first reported case of intra-abdominal chronic expanding hematoma in a dog. It is also unique given its features of iron-deficiency anemia caused by internal blood loss.

Chronic encapsulated intracerebral hematoma: Three case reports and a literature review

Background:

Chronic encapsulated intracerebral hematoma (CEIH) is one type of intracerebral hematoma that sometimes grows progressively while forming a capsule and presenting with neurological deficits. Although many cases of CEIH have been reported, correct preoperative diagnosis is very difficult. Only around 20% of cases are diagnosed preoperatively.

Case Description:

We encountered three cases of CEIH in which causes were unidentified and difficult to diagnose. All three cases were treated surgically. In the first case, a 59-year-old male was diagnosed preoperatively with metastatic brain tumor. In the second case, a 62-year-old female was diagnosed preoperatively with glioblastoma. The third case involved a 58-year-old female diagnosed preoperatively with CEIH.

Conclusion:

We should keep in mind that CEIH is a differential diagnosis for intracerebral space-occupying lesions. This report describes these three cases and discusses imaging findings and characteristics of CEIH.

A chronic intracerebral fluid hematoma

Intracerebral hematoma usually resolves and a chronic fluid hematoma is rare. We describe a rare case of intracerebral fluid hematoma. This report describes a case of intracerebral fluid hematoma mimicking a brain tumor and discusses the characteristics of this condition. A 70-year-old woman had a six-month history of memory disturbance. Computed tomography scan showed a low-density lesion with a partial high-density area in the right frontal lobe. MRI revealed a lesion of the main cystic portion showing high intensity on both T1 and T2 weighted images with a low-intensity solid portion in the anteromedial side. The lesion was adjacent to the lateral ventricle. Craniotomy was carried out and the lesion was removed. Pathological examination of the solid portion revealed that the diagnosis was reactive changes due to intracerebral hemorrhage. In our case, there was a possibility that the hematoma was diluted with cerebrospinal fluid, and coagulation might have been prevented.

Chronic encapsulated intracerebral hematoma associated with cavernous malformation

Chronic encapsulated intracerebral hematoma (CEIH) is a rare cerebrovascular disease that behaves as a slowly expanding lesion with a gradual onset. It is well established that CEIH is associated with arteriovenous malformations; however, CEIH associated with cavernous malformation (CM) is extremely rare. We herein report a case of CEIH associated with CM, and discuss its pathogenesis. A 12-year-old female was admitted to our hospital because of a one week history of progressive headache and nausea. Brain computed tomography scan and magnetic resonance imaging showed an intracerebral hematoma surrounded by edema in the right frontal lobe. One week later, her headache and nausea worsened, and a brain computed tomography scan revealed the enlargement of hematoma. A right frontal craniotomy was performed. The capsule, mass, and hematoma were totally removed. Histological examination confirmed the diagnosis of CEIH associated with CM. Immunohistochemical analysis revealed increased expression of vascular endothelial growth factor (VEGF) and the VEGF receptor-1 in the endothelium and fibroblasts. Our findings suggest that the activated VEGF pathway might have positively contributed to development of CEIH in the present patient.

Progressing haemorrhagic stroke: categories, causes, mechanisms and managements

Haemorrhagic stroke is a severe stroke subtype with high rates of morbidity and mortality. Although this condition has been recognised for a long time, the progressing haemorrhagic stroke has not received adequate attention, and it accounts for an even worse clinical outcome than the nonprogressing types of haemorrhagic stroke. In this review article, we categorised the progressing haemorrhagic stroke into acute progressing haemorrhagic stroke, subacute haemorrhagic stroke, and chronic progressing haemorrhagic stroke. Haematoma expansion, intraventricular haemorrhage, perihaematomal oedema, and inflammation, can all cause an acute progression of haemorrhagic stroke. Specific 'second peak' of perihaematomal oedema after intracerebral haemorrhage and 'tension haematoma' are the primary causes of subacute progression. For the chronic progressing haemorrhagic stroke, the occult vascular malformations, trauma, or radiologic brain surgeries can all cause a slowly expanding encapsulated haematoma. The mechanisms to each type of progressing haemorrhagic stroke is different, and the management of these three subtypes differs according to their causes and mechanisms. Conservative treatments are primarily considered in the acute progressing haemorrhagic stroke, whereas surgery is considered in the remaining two types.

Chronic encapsulated expanding hematoma in nonfunctioning pituitary adenoma

The diagnosis and treatment of pituitary macroadenomas with entire hematoma fluid accumulation are problematic. Such lesions are often difficult to completely resect, and recurrence is not uncommon. We present five cases of pituitary macroadenomas entirely composed of hematoma fluid and investigated their histopathology to clarify the mechanism of the hematoma fluid accumulation. Five patients with pituitary adenoma and significant intra-tumor hematoma underwent transsphenoidal resection and were retrospectively reviewed for their clinical status, findings on magnetic resonance imaging (MRI), intraoperative findings, and histopathology. The specific surgical techniques used to address these cases were also reviewed. All patients were diagnosed with nonfunctioning pituitary adenomas by histopathological examination. MRI showed all tumors extended to the cavernous sinus. Histopathology showed tumor tissues were located between the thick granulation tissue and the pseudocapsule of the tumor. The thick granulation tissues were composed of collagenous layers, neovascular vessels, and necrotic red blood cells, indicating repeat hemorrhage from the granulation tissues. The boundary between adenoma and normal pituitary gland was identified during surgical removal in four patients and was not identified in the other patient who showed a recurrence 2 years later. Clinical and histopathological findings indicate hematoma fluid accumulation in the present cases is caused by repeat hemorrhage from the reactive granulation tissues and can be regarded as a chronic encapsulated expanding hematoma. In these cases, the boundary between adenoma and normal pituitary gland should be identified before puncturing the hematoma fluid to minimize the risk of tumor recurrence.

Organizing hematoma mimicking brain tumor

A 64-year-old man was referred to our hospital with progressive loss of function in his right upper and lower extremities. Unenhanced computed tomographic showed a high-density nodular lesion in the left basal ganglion with surrounding hypoattenuation. Brain magnetic resonance imaging demonstrated a predominantly cystic mass with multiple internal septa and an eccentric solid component showing enhancement. Histological examination revealed organizing blood clot and piloid gliosis. This unusual appearance of a mass-like organizing blood clot should be considered in the differential diagnosis when an encapsulated cystic mass with nodular component following the signal characteristics of old blood on MRI is encountered.

A late haemorrhagic complication in an arteriovenous malformation cured with radiosurgery. Case report

Radiosurgery is a recognized safe form of treating and usually curing arteriovenous malformations (AVMs). Complications related to radiosurgery, especially late sequelae, are rare. Such sequelae may be secondary to incomplete treatment of the original lesion such as haemorrhage, or secondary to the radiation damage to the tissue, or both. Sometimes treatment may induce new lesions. We report a patient who had an AVM cured with radiosurgery, but developed hemisensory loss acutely and had changes on MRI in keeping with a haematoma. We discuss the possible differential diagnosis that should be considered.