Delayed presentation of an arteriovenous malformation after cerebellar hemangioblastoma resection-Case report

Cerebellar Hemangioblastoma Mimicking Arteriovenous Malformation: A Case Report

Hemangioblastoma (HBM) is a tumor distinguished by the presence of stromal cells and small vessels. These stromal cells represent stem cells, which, due to the influence of the neoplasm, proliferate and differentiate into "vasoformative elements" that create new blood vessels. Hemangioblastomas resemble arteriovenous malformation (AVM) in imaging features, characterized by an apparent vascular blush, the presence of multiple feeding vessels, and evident draining veins observed on digital subtraction angiography (DSA). Our study presents a case of HBM in the right cerebellar hemisphere mimicking AVM. The patient had been diagnosed with AVM in the same location two years ago and managed with endovascular embolization. One month prior, the patient experienced severe headaches, imbalance, nausea, left ear fullness, blurry vision, and high blood pressure. The imaging feature suggests HBM rather than AVM. The patient next underwent sub-occipital craniotomy and tumor resection with external ventricular drainage (EVD) insertion. The histopathological report of the excised mass confirmed HBM. In conclusion, AVM and HBM rarely occur together. Recent research indicates that HBM and AVM have exact embryologic origins and need later genetic alterations to develop into symptomatic lesions. Further research is required to clarify the uncommon combination of these lesions.

Hemangioblastoma and arteriovenous malformation in the same patient: a not random association or two isolated entities? Systematic review starting from a unique case

BACKGROUND

The association between intracranial hemangioblastomas and arteriovenous malformations has been documented in very few cases in literature since 1965 and might present in three modalities: "intermixed, adjacent and separated (spatially and temporally)". Often, the pattern of presentation is "intermixed". According to our systematic review, we propose an adjustment of the previous classification, specifically for these entities. We describe the first case of a truly "spatially separated" association between these two lesions.

METHODS

Our study encompassed all adult patients diagnosed with both intracranial hemangioblastoma and AVM who were evaluated in the last 20-year period, from 2003 to 2023 at Helsinki University Hospital. Cases of this coexistence were retrospectively identified and collected from clinical records. For the systematic review, studies reporting the coexistence of hemangioblastoma and AVM in adult patients (>18 years old) were selected. Given the rarity of this pattern, case reports were also included.

RESULTS

The combined analysis of our systematic review and institutional retrospective study revealed a total of only seven identified cases. We applied the classification of neoplasms and AVM by Yano, modifying and adapting it into our screened patient series. We systematically reclassified "adjacent" and genuinely "spatially separated" patterns based on the vascular axis supplying both lesions.

CONCLUSIONS

Hemangioblastomas and AVMs rarely coexist in the same patient. Our study reports the first instance of a truly "spatially separated" sporadic association between these vascular lesions. The rarity of such coexistence underscores the need for a nuanced and systematic classification to guide the management of these infrequent cases.

Cerebellar Hemangioblastoma Associated With a Vascular Malformation: A Case Report Treated With Surgery and Radiosurgery

Hemangioblastoma is well known as an essentially benign cystic and/or solid tumor classified WHO grade I, mainly originated in the posterior fossa. One of the characteristics of this tumor is very rich vasculature in and around the tumor. We have encountered a case of hemangioblastoma in association with a vascular anomaly near the tumor, though they were located separately by the tentorium. A vascular anomaly with arteriovenous (AV) shunting flow in the left occipital lobe was verified at angiography, which received a blood supply from left occipital artery and drained to occipital cortical veins. Successful removal of the cerebellar tumor and pathological diagnosis of hemangioblastoma was made. The second angiography in our hospital demonstrated the same vascular anomaly above the tentorium with feeding artery of posterior cerebral artery, a small nidus, and cortical draining veins, which were less obviously stained. Only the arteriovenous malformation (AVM) nidus in sigmoid vein was targeted for radiosurgery and 20 Gy at the margin was delivered. Since AV shunting was less remarkable on the second angiography than that on the first angiography may be because of a decreased vascular supply to the supratentorial AVM after surgical resection of the infratentorial hemangioblastoma and might indicate an indirect connection between the two lesions.

'De Novo' Brain AVMs-Hypotheses for Development and a Systematic Review of Reported Cases

Background and Objectives: Brain arteriovenous malformations AVMs have been consistently regarded as congenital malformations of the cerebral vasculature. However, recent case reports describing "de novo AVMs" have sparked a growing debate on the nature of these lesions. Materials and Methods: We have performed a systematic review of the literature concerning de novo AVMs utilizing the PubMed and Google Academic databases. Termes used in the search were "AVM," "arteriovenous," "de novo," and "acquired," in all possible combinations. Results: 53 articles including a total of 58 patients harboring allegedly acquired AVMs were identified by researching the literature. Of these, 32 were male (55.17%), and 25 were female (43.10%). Mean age at de novo AVM diagnosis was 27.833 years (standard deviation (SD) of 21.215 years and a 95% confidence interval (CI) of 22.3 to 33.3). Most de novo AVMs were managed via microsurgical resection (20 out of 58, 34.48%), followed by radiosurgery and conservative treatment for 11 patients (18.97%) each, endovascular embolization combined with resection for five patients (8.62%), and embolization alone for three (5.17%), the remaining eight cases (13.79%) having an unspecified therapy. Conclusions: Increasing evidence suggests that some of the AVMs discovered develop some time after birth. We are still a long way from finally elucidating their true nature, though there is reason to believe that they can also appear after birth. Thus, we reason that the de novo AVMs are the result of a 'second hit' of a variable type, such as a previous intracranial hemorrhage or vascular pathology. The congenital or acquired characteristic of AVMs may have a tremendous impact on prognosis, risk of hemorrhage, and short and long-term management.

De novo thalamic arteriovenous malformation in a boy with a brainstem cavernous malformation

Brain arteriovenous malformations (bAVMs) have long been considered to be congenital, developing between the third and eighth weeks of embryogenesis. However, cases reporting their de novo formation suggest that these lesions can develop after birth and have challenged this concept. We present a case of a 6-year-old boy with a history of a brainstem cavernous malformation diagnosed after birth who later developed a de novo bAVM. The de novo occurrence of this bAVM distant to the site of the cavernous malformation and a prior negative catheter angiography contributes to the uncertainty of the dynamics and pathophysiology of bAVMs.