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the cavernous malformation ( cm ) , also known as cavernous angioma or cavernoma , is a vascular malformation characterized by the presence of sinusoid - like capillary vessels containing blood with poor circulation.4 ) cms vary in size from a few millimeters to a several centimeters .
however , unlike giant aneurysms , defined as having diameters of 25 mm and over , no threshold dimension has been accepted for a giant cm ( gcm).8 ) kim et al.12 ) studied a variety of cms sized between 1 mm and 75 mm , and reported a mean size of 14.2 mm .
the majority of cms are small but they can occasionally reach significant size . although arbitrary , lawton et al.13 ) defined a gcm as a cm with a diameter greater than 6 cm .
although rare , if cms are over a certain size , they may be referred to as gcms .
a right - handed , 19-year - old male was referred to the division of neurosurgery due to right sided motor weakness ( grade ii / ii ) that persisted for 3 months . since the age of 5 ,
the patient had been clinically diagnosed with 1st grade mental retardation and epilepsy with daily prescription medication as follows : levetiracetam 500 mg 1 t twice a day ( bid ) , valproate 600 mg 1 t bid , topiramate 100 mg 1 t bid , clonazepam 0.5 mg 1 t per day . also , the patient had familial history of an 18-year - old sister with an astrocytoma on her left pons , diagnosed when she was 10 years old . after a surgical resection , she fully recovered .
the patient 's computed tomography ( ct ) scan revealed a well - defined cystic mass with a size of 7.24.66 cm filled with 2 cm intra - cystic nodule on left fronto - parietal lobe .
the mass was lobulated , ovoid , and bulging , and had surrounding edema with mass effect .
the patient 's magnetic resonance imaging ( mri ) showed the mass as low signal intensity ( si ) in t1-weighted images ( wi ) , but high si in t2wi ( fig .
the 2 cm intra - cystic nodule was heterogeneous high si in t1wi , low si in t2wi and slightly enhanced , heterogeneous high si in t1-weighted contrast - enhanced coronal image ( fig .
. based on the ct and mri findings , the lesion was diagnosed as a low - grade glioma or congenital infection such toxoplasmosis or cytomegalovirus , or even a neurocysticercosis .
a left frontal craniotomy was performed , followed by a transcortical approach to remove the mass . from the mri ,
the t1 low si , t2 high si lesion in the surgical field was identified as a cyst with yellow fluid , and was removed with aspiration .
the intra - cystic nodule , which was 22 cm in size , freely movable , relatively hard , with a yellow surface , and low vascularity , was resected en bloc .
however , the histological exams of the mass revealed it to be a cm ( fig .
2 ) . the follow - up ct scan showed no residual lesion ( fig .
cms are relatively rare vascular anomalies composed of abnormal cavernous endothelial - lined spaces lacking smooth muscle and intervening neural tissue.2 ) these malformations have a reported prevalence rate of 0.4 to 0.9% based on autopsy and mri series.22 ) most cms occur sporadically as solitary lesions.2)10 ) on rare occasions , cms reach a significant size , 6 cm in diameter or larger , becoming what may be defined as a gcm.13 ) the pattern of growth is probably recurrent bleeding , followed by organization of the clot , pseudocapsule formation , and secondary expansion.3 ) although cms may occur in patients in their twenties to forties , the majority of gcms develop in children , with the youngest reported case being 3.5 months of age.1)3)4)20)22 ) the gender balance is equal in cms , but there seems to be a female predominance in gcms.4)22 ) familial cms account for 20% to 50% of patients.18 ) however , in review of literature for gcms , no familial occurrence has been reported.22 ) multiple cms may occur in 10% to 30% of sporadic cases and up to 84% in familial cases , but multiple gcms have not been reported.22)23 ) the gcm may clinically present with symptoms ranging from headaches to catastrophic , life - threatening hemorrhages . a significant number of gcms present with a seizure , acute - onset of a severe headache , or a new focal neurologic deficit.8 ) on the other hand , large , slow - growing lesions often manifest with increased intracranial pressure from obstructive hydrocephalus or the mass occupying significant space . the subtle onset of right sided motor weakness , as seen in this case , has been reported in literature as the result of the mass growth occurring slowly and without significant hemorrhage.3 ) the causes of cystic degeneration of cms remain unknown .
research points to recurrent minor hemorrhage of internal vascular sinuses or neocapillaries within cms as possible factors .
bleeding episodes within a cm cause the osmotic pressure across the cm membrane to change , leading to gradual fluid accumulation within the cm , cystic degeneration , and subsequent cm growth.15)19 ) cystic degeneration within the cms in the cerebellopontine angle is a progressive process ; cms may be at different stages . as a result ,
when imaging examinations are performed , the cms may show various features of cystic degeneration .
for example , multiple cysts may be seen within the solid component of the cm , as in this case , and a large cyst may be seen in combination with small nodules .
all of these features contribute to different enhancement patterns upon contrast - enhanced ct or mri examination , which can vary from no enhancement at all to marked enhancement .
appear only rarely.18 ) cms in the form of a cystic growth with a well - defined capsule are unusual.18 ) on the other hand , in existing reports of gcms , the radiographic appearances vary widely from completely solid to primarily cystic , or heterogeneous masses composed of both components.11 ) also , the presence of contrast enhancement is highly inconsistent , ranging from nonexistent to intensely enhancing .
a number of studies report cm lesions that mimic the appearance of high - grade glial neoplasms such as oligodendrogliomas , because they appear tumefactive on mri , having an infiltrative pattern , as well as significant perilesional edema.13)22 ) initially , in this particular case , the mass was diagnosed as a glioma , perhaps oligodendroglioma or anaplastic astrocytoma , due to visible calcifications , perilesional edema and mass effect.6)13)22 ) considering the multiple parenchymal calcifications , a well defined cystic mass , and an intra - cystic nodule , we suspected a congenital infection , such toxoplasmosis or cytomegalovirus infection , or even a neurocysticercosis.14)21)22 ) therefore , we carried out a serologic test for cytomegalovirus antibody immunoglobulin m , cysticercus antibody , but the serology was negative . during the histopathological biopsy
, we found hemosiderin depositions , necrotic tissues , microvasculatures , and an absence of neural tissue , leading to the conclusion that the mass was a cm.1 ) in a retrograde analysis , the hemosiderin depositions in gradient - echo view and the absence of infiltrative pattern in mri support the likelihood that the mass is a cm rather than a glioma.1 ) calcifications around gcms have been previous documented.16)20 ) however , diffuse multiple calcifications co - occurring , such as this case , is unprecedented .
diffuse multiple calcifications may be formed separately from gcms , by diseases such as toxoplasmosis , rubella and cytomegalovirus as congenital infections.5)7)21 ) in our case , the patient was diagnosed with 1st grade mental retardation and epilepsy when he was 5 years of age . however , at the time , no study was done for brain imaging or congenital infections .
it is highly probable that seizure and mental retardation could be congenital infections but it can not be conclusively identified.5)7)9 ) genetically cerebral intraparenchymal cms are associated with 3 cerebral cm ( ccm ) genes , ccm-1 , ccm-2 and ccm-3 .
the disease is autosomal dominant and almost all mutations in the ccm genes result in loss of function .
it has been suggested that a ' second hit ' in a patient with an existing embryonal nonfunctioning ccm gene results in complete loss of function and proliferation of endothelial cells.17 ) we did not investigate genetic implications in this case .
the current neurosurgical management of cms , when indicated , consists of image - guided surgical resection of the entire mass , regardless of the size .
standard surgical indications include recurrent hemorrhage , progressive neurologic deterioration , and medically refractory epilepsy.4 ) when resection may have an unacceptably high risk , such as cms located in eloquent cerebral parenchyma , stereotactic radiosurgeries have been attempted with varying degrees of success and increased risk of postoperative hemorrhage .
many cases report favorable outcomes with surgical resection of gcms.1 ) our surgical approach was different from the typical gcm resection , since the lesion was almost entirely cystic .
we took a transcortical approach , followed by cyst aspiration , and intra - cystic nodule removal .
the postoperative ct was almost entirely clear of the mass , and the patient 's right - sided motor weakness improved with no complications .
in this case , a gcm with a large cyst was examined and treated by a surgical resection to alleviate the patient 's neurologic deficit . this report serves to broaden the differential diagnosis of large cystic supratentorial intracranial masses .
since the imaging char acteristics , clinical presentations and natural history of gcms are variable , the possibility of gcms should be considered in differential diagnosis of intracranial mass lesions .
cerebral cavernous malformation with giant cysts is rare and literature descriptions of its clinical features are few . in this case study , 
 the authors describe the clinical symptoms , radiological findings , and pathological diagnosis of cerebral cavernous malformations with giant cysts , reviewing the relevant literature to clearly differentiate this from other disease entities . 
 the authors present a case of a 19-year - old male with a giant cystic cavernous malformation , who was referred to the division of neurosurgery due to right sided motor weakness ( grade ii / ii ) . 
 imaging revealed a large homogenous cystic mass , 7.24.66 cm in size , in the left fronto - parietal lobe and basal ganglia . 
 the mass had an intra - cystic lesion , abutting the basal portion of the mass . 
 the initial diagnosis considered this mass a glioma or infection . 
 a left frontal craniotomy was performed , followed by a transcortical approach to resect the mass . 
 total removal was accomplished without post - operative complications . an open biopsy and a histopathological exam diagnosed the mass as a giant cystic cavernous malformation . 
 imaging appearances of giant cavernous malformations may vary . 
 the clinical features , radiological features , and management of giant cavernous malformations are described based on pertinent literature review .