 |
| About Bioline | All Journals | Testimonials | Membership | News |
|
||||||
|
||||||
Neurology India, Vol. 59, No. 5, September-October, 2011, pp. 775-776 Letter to Editor Giant primary intraosseous calvarial hemangioma of the occipital bone Prakash Nair1, Arun Kumar Srivastava1, Raj Kumar1, Kapil Jain1, Rabi Narayan Sahu1, Mukul Vij2, Manoj Jain2 1 Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India PMID: 22019676 DOI: 10.4103/0028-3886.86568 A 20-year old female presented with progressively increasing holocranial headache, unsteadiness of gait, and visual obscuration of 2 months duration. Right ventriculoperitoneal (VP) shunt for signs of raised intracranial pressure had been done by the referring neurosurgeon. Neurological examination revealed papilledema and right-sided cerebellar signs. Skull examination revealed an irregular bony hard immobile swelling 3 cm lateral to the inion on the right involving the occipital bone. Plain computerized tomography (CT) demonstrated a hyperdense-calcified lesion in the posterior fossa contiguous with the occipital bone displacing the right cerebellar hemisphere and the fourth ventricle with obstructive hydrocephalus [Figure - 1]a. Magnetic resonance imaging (MRI) showed an extra-axial lesion in the posterior fossa compressing the right cerebellar hemisphere effacing the fourth ventricle causing hydrocephalus. The lesion was isointense on T1W [Figure - 1]b and hyperintense on T2W [Figure - 1]d images with brilliant enhancement on gadolinium contrast injection [Figure - 1]c. The lesion was seen infiltrating the occipital bone and subcutaneous tissue. MR-venogram showed occlusion of right transverse sinus by the lesion. The images were suggestive of a posterior fossa convexity meningioma infiltrating the occipital bone with hydrocephalus. During surgery, the tumor was found to be intraosseous, the outer table was thin and the inner table was eroded by the tumor, which was entirely extradural and extremely vascular causing torrential bleeding from large trabecular blood-filled channels. Blood loss at the end of the procedure was 4200 ml. Tumor was excised completely with a rim of normal bone. Complete excision was confirmed on the postoperative CT scan [Figure - 2]. Histological examination showed large thin-walled vascular channels with small thin-walled and angulated capillary sized blood-filled vessels, suggestive of a cavernocapillary hemangioma of the occipital bone [Figure - 3]. Postoperatively, she developed right-sided hemiparesis with increase in right-sided cerebellar signs, which had resolved completely at the last follow-up at 6 months. Hemangiomas account for 0.7% of all bone tumors. [1] Vertebral column is the most common site and calvarium is involved in 20% of cases. Primary calvarial hemangioma (PCH) forms 10% of the benign neoplasms of the skull. Parietal and frontal bones are most commonly involved [2] with occipital, sphenoid, and temporal bone involvement being rare. These lesion occur in fourth decade; women are affected two to four times more often than men. [3] PCH may present as (1) globular expansile variety which arises from the skull base and presents as a space-occupying lesion and (2) a sessile type causing expansion of the diploe of the skull; however, significant intracranial extension is rare. [4] PCH are usually asymptomatic but may manifest with cosmetic disfigurements, facial dysmorphic features, cranial nerve deficits, local pain, or rarely seizures. In our patient, the lesion had attained a large size causing ipsilateral cerebellar signs and obstructive hydrocephalus, an extremely rare presentation. Histologically, hemangiomas are classified according to the predominant type of vascular channel: cavernous, capillary, arteriovenous, and venous. On plain skiagram, PCH is a solitary lytic lesion with a sclerotic rim. There may be a characteristic "honeycomb" trabecular pattern or "sunburst" pattern with striations radiating from the center. On CT, PCH is a lucent lesion with multiple interposed trabeculae. The lesion is characterized by distinct margins, appearing to replace the full thickness of the calvarium. [7] These lesions may have multiple bony spurs projecting into the center of the lesion which lends them the appearance often referred to as "wagon-wheel," "corduroy-cloth," or the "sunburst" appearance. [7] In our patient, it was hyperdense and with bulky central and spiculated peripheral calcification and hyperostosis of the underlying bone with no distinct margins or lytic change. On MRI, PCH typically appear well-circumscribed, hyperintense on T1W and T2W images with bright enhancement on contrast administration; [4] however, the signal intensity of PCH may vary; hyperintensity on T1-weighted images is a differentiating feature of the PCH [5] and indicates the presence of fat in these lesions, [6] loss of fat with hypointensity on T1W indicates an aggressive PCH [7] which was a feature of our case. The presence of a dural tail mimicking a meningioma may be seen, [8] like in our patient. Radiological features may help in establishing the diagnosis; however, only histological diagnosis is definitive. Enbloc resection is the standard approach to minimize blood loss, as the sinusoids are undisturbed. [3] In conclusion, we suggest that PCH must be kept in the differential diagnosis when large intracranial extra-axial lesions are encountered. References
Copyright 2011 - Neurology India The following images related to this document are available:Photo images[ni11236f1.jpg] [ni11236f3.jpg] [ni11236.jpg] [ni11236f2.jpg] |
| |||||||||
