Large Calcified Cystic Cavernous Angioma in the Thalamus
-Case Report-
Kazufumi SATO and Toshihiko KUBOTA
Department of Neurosurgery, Fukui Medical School, Fukui
Abstract
A 52-year-old female presented with an unusual large cystic cavernous angioma with dense calcification in the thalamus manifesting only as headache despite the large mass with surrounding brain edema. Both T, and T2-weighted magnetic resonance images revealed a large cystic mass with an intramural nodule appearing a reticulated, irregular mixed intensity core. The lesion was totally removed through a transcortical-transventricular approach. The postoperative course was uneventful with no signs of neurological deficit or residual mass 5 years later.
Key words: cavernous angioma, cyst, calcification, thalamus, computed tomography,
magnetic resonance imaging
Received May 11, 1994; Accepted June 30, 1994
Introduction
Cavernous angioma is a relatively rare vascular malformation in the central nervous system. Recently, cavernous angioma has been found more often by computed tomography (CT)",", 12,15,16) and/or
magnetic resonance (MR) imaging."`,") Cavernous angioma frequently contains small cysts and/or tiny calcifications.') We describe a patient with a cavernous angioma in the thalamic region containing a large cyst and dense calcification.
Case Report
A 52-year-old female presented with a 2-year history of intermittent occipitalgia. Neurological examination on admission was normal. Plain x-ray films showed an abnormal calcification. Precontrast CT revealed a mass with a diameter of approximately 5 cm in the right thalamic region containing a large cyst with irregular-shaped dense calcification (Fig. 1 upper). Postcontrast CT showed the slightly enhanced cyst wall. MR imaging demonstrated a large low-intensity (but higher than cerebrospinal fluid intensity) mass containing an irregular mixed intensity
area on the T,-weighted images (Fig. 1 middle). The T2-weighted MR images revealed a high-intensity le
sion with surrounding brain edema and a reticulated, irregular mixed intensity core (Fig. 1 lower).
The lesion was totally removed by a transcortical
transventricular approach through a right temporo
parieto-occipital craniotomy. The large cyst contained xanthochromic fluid.
Histological examination found the lesion containing of a network of vascular channels. The vessel walls usually showed collagenous thickening, and thrombosed vessels were frequently seen. Roundish calcified bodies were closely related to the thrombosed vessels. Linear calcification on the walls of non-thrombosed vessels was occasionally observed
(Fig. 2 upper). Numerous calcified bodies were present in the surrounding gliosis (Fig. 2 middle). The cyst wall consisted of fibrous tissue containing neocapillaries with proliferation of inflammatory cells and hemosiderin deposits (Fig. 2 lower). The histological diagnosis was cavernous angioma.
The postoperative course was uneventful. Followup examination 5 years later found no neurological deficit and MR imaging revealed no residual mass
(Fig. 3).
Discussion
Intracranial vascular hamartomas are classified into four groups based on histological features: 1) capillary telangiectasis, 2) cavernous angioma, 3) arteriovenous malformation, and 4) venous malformation. Cavernous angioma is a well-defined lesion consisting of sinusoidal vascular channels lined by a single layer of endothelial cells. The walls of the vessels consist of collagen fibers, and have no mus
cle nor elastic fiber. The surrounding stroma shows fibroblastic proliferation without intervening
neural tissue. The histological differentiation be
tween cavernous angioma and capillary telangiectasis
is sometimes difficult, ia,2o) and the association of
these lesions has been reported.') The histological ap
pearance of our case was compatible with cavernous angioma, but the vessel walls were usually thick and
thrombosed vessels were frequent.
Fig. 1 upper: Precontrast CT scans showing a large cystic mass with dense calcification in the right thalamic region. middle: Axial T,-weighted MR images (spin echo [SE] 350/35 msec) showing a large low-intensity mass with irregular mixed intensity. lower: Axial T2-weighted MR images (SE 2000/50 msec) showing the lesion as a large high-intensity mass with a reticulated core of irregular mixed intensity.
Fig. 2 upper: Photomicrograph showing network of vascular channels with roundish calcified bodies (arrows) and linear calcification on the vessel walls (arrowheads). Hematoxylin and eosin (HE) stain, x 75. middle: Photo
micrograph showing numerous calcified bodies in the gliosis. HE stain, x 75. lower: Photomicrograph of the cyst wall showing fibrous tissue containing neocapillaries and prolifera
tion of inflammatory cells. HE stain, x 170.
The cerebral hemisphere is the most common site for intracranial cavernous angioma.a,",20I The
posterior fossa, basal ganglia, or ventricular wall are
less frequently affected, and the thalamus is seldom involved. 9,12,191 The most common clinical symptom
of cavernous angioma is seizures,',',' 1,15-18,20) and others include headaches, intracranial bleeding, or focal neurological deficits. Our patient only manifested headache despite the large lesion associated with surrounding brain edema.
Cavernous angioma with a large cyst is unusual, 3,6,7,1',19) compared to the association of small cysts. Although the etiology of cyst formation is not established, cyst growth may be the result of recurrent hemorrhage from sinusoids of the vascular malformation or from the neocapillaries of the cyst wall. The cyst membrane is histologically similar to the outer membrane of chronic subdural hematoma. Our histological findings also support the relationship between repeated minor bleeding and the formation of a large cyst.
Calcifications in cavernous angioma are visualized by plain x-ray films in 11-40% of cases. 4,13,20) Calcification nests occur particularly within thrombosed luminae,l,a,13,14) or intervascular spaces.4) In our case, three types of calcification nest were noted: 1) roundish calcification closely related to the thrombosed vessels, 2) linear calcification on the wall of non-thrombosed vessels, and 3) roundish calcified
bodies in the gliosis. These calcifications are considered to be dystrophic calcification occurring under
pathological conditions such as calcified tumors or aortic media.21
The neuroimaging appearance of cavernous an
gioma is well known. CT shows these lesions as a well-defined hyperdense mass with mild postcontrast enhancement. The finding of calcification is sug
gestive of cavernous hemangioma,1,8,12,15,16) but is nonspecific and indistinguishable from calcifications
seen in other intracranial lesions."') The CT ap
pearance of our case was unusual for cavernous angioma, so the differential diagnosis from other
cystic lesions such as astrocytoma, oligodendro
glioma, meningioma, or parasitic cyst was difficult. The characteristic MR imaging appearance of cav
ernous angioma is a reticulated mixed intensity
core with a surrounding low-intensity rim especial
ly on the T2-weighted images. 11-12,18) The mixed in
tensity area is due to varying blood flow within the lesion, thrombosis, recanalization, calcification,
and intralesional hemosiderin.18) Other MR imaging
patterns include focal hyperintense, focal inhomo
geneous hyperintense, and multifocal isointense centers. 18) In our case, the intramural nodule appeared
as a mixed intensity area on both T1 and T2
weighted images. MR imaging is the most sensitive
diagnostic method for cavernous angioma even
with a large cyst and dense calcification.
Intracerebral cavernous hemangioma can usually
be treated by surgery, regardless of size or preop
erative symptoms. Surgery is indicated to avoid the risk of subsequent bleeding or rapid growth of the
cyst.4,9,17,20) In most patients, surgical removal is easy and the outcome of total removal is excel
lent.a,is,2o1
Fig. 3 Axial T1-weighted MR image (SE 500/38 msec) 5 years after the operation showing no residual mass, and only operation scars in the right thalamus and cerebral cortex.
References
1) Ahmadi J, Miller CA, Segall HD, Park S, Zee C, Becker RL: CT patterns in histopathologically complex cavernous hemangiomas. AJNR 6: 389-393, 1985
2) Anderson HC: Calcification processes. Pathol Annu 15: 45-75, 1980
3) Bellotti C, Medina M, Oliveri G, Barrale S, Ettorre F: Cystic cavernous angiomas of the posterior fossa. Report of three cases. JNeurosurg 63: 797-799, 1985
4) Giombini S, Morello G: Cavernous angiomas of the brain. Account of fourteen personal cases and review of the literature. Acta Neurochir (Wien) 40: 61-82, 1978
5) Hayashi T, Fukui M, Shojima K, Utsunomiya H, Kawasaki K: Giant cerebellar hemangioma in an in
fant. Case report. Childs Nerv Syst 1: 230-233, 19856) Iplikcioglu AC, Benli K, Bertan V, Ruacan S: Cystic
cavernous hemangioma of the cerebellopontine angle. Case report. Neurosurgery 19: 641-642, 1986
7) Khosla VK, Banerjee AK, Mathuriya SN, Mehta S: Giant cystic cavernoma in a child. Case report. J Neurosurg 60: 1297-1299, 1984
8) Pozzati E, Padovani R, Morrone B, Finizio F, Gaist G: Cerebral cavernous angiomas in children. J Neurosurg 53: 826-832, 1980
9) Ramina R, Ingunza W, Vonofakos D: Cystic cerebral cavernous angioma with dense calcification. Case report. J Neurosurg 52: 259-262, 1980
10) Rapacki TFX, Brantley MJ, Furlow TW Jr, Geyer CA, Toro VE, George ED: Heterogeneity of cerebral cavernous hemangiomas diagnosed by MR imaging. J Comput Assist Tomogr 14: 18-25, 1990
11) Rigamonti D, Drayer BP, Johnson PC, Hadley MN, Zabramski J, Spetzler RF: The MRI appearance of cavernous malformations (angiomas). J Neurosurg 67: 518-524, 1987
12) Roda JM, Alvarez F, Isla A, Blazquez MG: Thalamic cavernous malformation. Case report. J Neurosurg 72: 647-649, 1990
13) Runnels JB, Gifford DB, Forsberg PL, Hanbery JW: Dense calcification in a larger cavernous angioma. Case report. J Neurosurg 30: 293-298, 1969
14) Russell DS, Rubinstein LJ: Pathology of Tumours of the Nervous System, ed 5. London, Edward Arnold, 1989, pp 727-735
15) Servo A, Porras M, Raininko R: Diagnosis of caver nous haemangiomas by computed tomography and
angiography. Acta Neurochir (Wien) 71: 273-282, 1984
16) Simard JM, Garcia-Bengochea F, Ballinger WE Jr, Mickle JP, Quisling RG: Cavernous angioma: A review of 126 collected and 12 new clinical cases.
Neurosurgery 18: 162-172, 1986
17) Steiger HJ, Markwalder TM, Reulen H: Clinico
pathological relations of cerebral cavernous angio mas: Observations in eleven cases. Neurosurgery 21:
879-884, 198718) Tomlinson FH, Houser OW, Scheithauer BW, Sundt
TM Jr, Okazaki H, Parisi JE: Angiographically occult vascular malformations: A correlative study of features on magnetic resonance imaging and histological examination. Neurosurgery 34: 792-800, 1994
19) Vaquero J, Cabezudo JM, Leunda G: Cystic cavernous haemangiomas of the brain. Acta Neurochir
(Wien) 67: 135-138, 198320) Voigt K, Yasargil MG: Cerebral cavernous haeman
giomas or cavernomas. Incidence, pathology, localization, diagnosis, clinical features and treatment.
Review of the literature and report of an unusual case. Neurochirurgia (Stuttg) 19: 59-68, 1976
Address reprint requests to: K. Sato, M.D., Department
of Neurosurgery, Fukui Medical School, 23
Shimoaizuki, Matsuoka-cho, Yoshida-gun, Fukui
910-11, Japan.