INTRODUCTION
Vascular malformations of the central nervous system are seen increasingly in clinical practice, because of advances in cross-sectional brain and spinal cord imaging. Cerebral vascular malformations are non-neoplastic lesions resulting from focal anomalies in the development of cerebrospinal circulation. Many surveys suggest that cavernous angiomas are present in 0.5% of population. They usually tend to be asymptomatic, but in 40% of cases, they can be symptomatic.
The four morphological types have been described in standard surgical pathology textbooks, namely, (1) capillary telangiectasia, (2) cavernous angioma or cavernoma, (3) venous angioma and (4) arteriovenous malformations. Cavernous angiomas are uncommon, but they account for 10%–25% of all vascular malformations. Mixed cavernous angiomas are very rare and remain exceptional. They can be either familial or sporadic.[1,2] Understanding of natural history of this entity is of great importance to avoid unnecessary morbid interventions. We present this case due to the heterogeneity of this entity and ongoing debate about ontogenesis, diagnosis and management.[3]
CASE REPORT
An 18-year-old male came to the neurosurgery outpatient department with a history of seizures for 3 years. The latest episode was on 1 month back. He did not give any other major past history of illness. There was no family history of similar illness. A thorough clinical examination did not reveal any neurological deficit. His vital parameters were within normal limits. The patient underwent plain axial computed tomography (CT) scan, and the report revealed a cortex-based lesion in the parafalcine right anterior frontal region measuring 3 cm × 3 cm × 3 cm involving the subcortical region. The lesion was heterogeneous and showed mixed attenuation with multiple small calcific and haemorrhagic foci. Neoplastic aetiology was suspected. Subsequent magnetic resonance imaging (MRI) revealed a well-defined heterogeneously hyperintense lesion at the same site measuring about 3.1 cm × 3.1 cm × 3 cm with a surrounding rim of haemosiderin deposition and internal haemorrhagic and calcific foci on T2-weighted images [Figure 1a]. A diagnosis of vascular malformation was made.
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Figure 1: (a) MRI showing a heterogeneous cortex-based lesion, (b) Vascular lumen with thick fibrous wall and calcification (Leishman stain, ×400), (c) Adjacent brain parenchyma (Leishman stain, ×100), (d) Areas with capillaries (arrow, Leishman stain, ×100). MRI: Magnetic resonance imaging
The patient was operated and underwent microsurgical resection. Multiple greyish-black fragmented bits of tissue were received for histopathological examination. The tissue was fixed in 10% formalin and paraffin processed. The 3–4 μ thick sections were cut and stained with haematoxylin and eosin (H and E). Histopathology examination showed closely opposed vascular channels made up of hyaline fibrous wall with lining of a single layer of endothelial cells and full of blood. There was no intervening cerebral parenchyma. Few areas of dystrophic calcification and ossification were seen. Normal cerebral parenchyma was noted at the periphery of the lesion [Figure 1b and Figure 1c]. Some areas showed prominent congested capillaries [[Figure 1]d, arrow]. Histochemical stains such as Verhoeff's and Masson's trichrome stains showed the absence of elastic tissue and muscle in vessel walls, respectively [Figure 2a and Figure 2b]. A histopathology diagnosis of cavernous angioma mixed or hybrid type was made.
Figure 2: Cavernous angioma (a) (Verhoeff's stain, ×400), (b) (Masson's trichrome stain, ×400)
DISCUSSION
The cavernous angiomas are also called cavernomas, and they occur in both children and adults with the mean age of the patient in the fourth decade. There is no gender predilection.[4,5] Majority of the cavernous malformations are sporadic, but 20% of cases may be familial. Sporadic cases often occur as a single lesion. The familial cavernous angiomas are often multiple and caused by mutations in CCM1, CCM2 and CCM3 genes. They are inherited as autosomal dominant.[3,6] In our case, there was no family history of similar illness.
The most common location is supratentorial region in the cerebrum though they can occur in basal ganglia, brainstem, cerebellum and spine. The signs and symptoms depend on the size and location of the lesion. They commonly present clinically with headache, seizures, focal neurological deficit, intracerebral haemorrhage or they could be asymptomatic.[7] Cavernous angiomas that are supra-tentorial frequently present with seizures, while those that are infra-tentorial present with focal neurological deficit or ataxia.[5] Seizures as only presentation in our case can be attributed to the proximity of the lesion to epileptogenic cerebrocortical tissue.
CT scan and CT angiography have a limited role in diagnosis because it lacks sensitivity and specificity for accurate diagnosis. In our case, similar observations were made. It typically shows a lesion with heterogeneous core typically surrounded by a low-signal-intensity haemosiderin rim.[6] MRI is the choice of diagnostic modality.[3]
In our case, histopathology examination showed a mixture of vascular channels with thick hyaline fibrous walls and areas with capillaries. The diagnosis of mixed or hybrid type was given. The histological features along with the absence of muscle and elastic tissue in the vessel wall in Masson's trichrome and Verhoeff's stains ruled out the possibility of arteriovenous malformation.
Existence of mixed type angiomas, in which vessels with hyalinised fibrous walls and capillaries in the same lesion, have created speculation that they may evolve from capillary telangiectasia. In contrast, some authors believe microhaemorrhages around cavernous haemangioma initiate processes of reactive angiogenesis which lead to the formation of a mixed form of malformations.[8,9] In our case, capillaries were seen in the centre of the lesion but not at the periphery of the lesion.
A conservative approach is observed in asymptomatic cavernous angiomas. Microsurgical resection is the only definitive treatment in symptomatic patients for supratentorial lesions. It has a high success rate with relatively low complications. Similar observations were made in our case. On follow-up of the patient after 1 year, he did not experience any symptoms.
CONCLUSION
Cavernous angiomas are uncommon lesions. Signs and presenting symptoms depend on the size and location of the lesions. CT findings are non-specific. MRI is the choice of diagnostic modality. The presence of both vessels with hyalinised fibrous walls and capillaries in the same lesion suggests a mixed or hybrid type which is very rare. A conservative approach is used to treat asymptomatic cases. Microsurgical resection is the choice of treatment in symptomatic patients.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
REFERENCES
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