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Year : 2014  |  Volume : 62  |  Issue : 1  |  Page : 71--73

Giant calcified intraventricular pilocytic astrocytoma: A rare entity

Rajinder Kumar1, Kanwaljeet Garg1, Aanchal Kakkar2, Mehar Chand Sharma2,  
1 Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
2 Department of Pathology, All India Institute of Medical Sciences, New Delhi, India

Correspondence Address:
Rajinder Kumar
Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi
India




How to cite this article:
Kumar R, Garg K, Kakkar A, Sharma MC. Giant calcified intraventricular pilocytic astrocytoma: A rare entity.Neurol India 2014;62:71-73


How to cite this URL:
Kumar R, Garg K, Kakkar A, Sharma MC. Giant calcified intraventricular pilocytic astrocytoma: A rare entity. Neurol India [serial online] 2014 [cited 2023 Feb 9 ];62:71-73
Available from: https://www.neurologyindia.com/text.asp?2014/62/1/71/128326


Full Text

Sir,

Pilocytic astrocytomas (PA) account for about 5-6% of all gliomas. In PA calcification is an infrequent finding. It is extremely rare for an intraventricular PA to present as a calcified mass. [1] We present two cases of giant intraventricular calcified PA. The clinical characteristics, image findings and pathological features of both patients are given in [Table 1] [Figure 1], [Figure 2], [Figure 3].{Figure 1}{Figure 2}{Figure 3}{Table 1}

Tumors of the lateral ventricles account for <1% of all intracranial tumors, most of which are benign and slow growing. [2] Bertalanffy et al. studied 143 patients of intraventricular tumors, most common being colloid cysts, craniopharyngioma and astrocytomas. [2] PA accounted for about 10% of these intraventricular lesions. [2]

Calcification is a feature in benign or slow-growing tumors like oligodendrogliomas, craniopharyngiomas, meningiomas, pineal gland tumors and choroid plexus tumors. Calcified PA have been reported in the optic nerve, hypothalamic/thalamus and superficially located cerebral tumors. Calcified intraventricular PA is extremely rare, only one case has been reported by Kim et al. in a 15-year-old girl who presented with complex partial seizures and there was an extensive psammomatous calcification. [1] Calcification has been reported in 9.3-19% of gliomas. [1] Diffuse low-grade astrocytomas demonstrate calcifications most frequently among gliomas. Up to 25% of PA have intratumoral calcification. [3] Usually a long time is required for the calcification to develop. [4] Calcified metastatic brain tumors have also been reported, with calcification mainly in the degenerative or necrotic tissue. [5],[6] Possible mechanisms of calcification in metastatic brain tumor include the reduced production of carbon dioxide, as a result of decreased metabolism of degenerative or necrotic tissue, which leads to the lesion becoming more alkaline than the surrounding tissues, which promotes calcification. [4] However, there was no necrosis in our cases, so some different mechanism might be responsible. In addition, there have been reports of disappearance of calcification from the calcified gliomas. [3] This might be due to relative ischemia due to fast growth, which results in the production of lactate and a fall in pH, and signifies fast growth or malignant change in the tumor.

There are many important implications of a heavily calcified intraventricular PA. First, it indicates a slow growing benign lesion which calcified over a period of time. Since these lesions produce symptoms because of obstruction of cerebrospinal fluid, they take a long time for to be symptomatic. Second, it makes the surgery challenging, as it is difficult to remove such large calcified tumor in one piece owing to its large size, which may cause surrounding brain injury. In our both cases, the calcified mass was very hard, could not be sucked with ultrasonic surgical aspirator or cut with a knife. The tumor had to be broken and was delivered out piecemeal using Kerrison punches and fine bone nibblers. In both cases, there was a pedicle with multiple vessels at the base, which could be seen only after most of the calcified mass was removed. The most difficult part of the surgery was to break it into smaller pieces without causing injury to surrounding parenchyma and without disrupting the pedicle with vessels. However, with careful dissection with patience, complete excision and excellent outcome can be achieved.

References

1Kim YE, Shin HJ, Suh YL. Pilocytic astrocytoma with extensive psammomatous calcification in the lateral ventricle: A case report. Childs Nerv Syst 2012;28:649-52.
2Bertalanffy H, Krayenbuhl N, Wess C, Bozinov O. Ventricular tumors. In: Youmans Neurological Surgery. 6 th ed. Philadelphia: Elsevier; 2011. p. 1534-68.
3Halpin S, Kingsley D. Disappearance of cerebral calcification as a sign of tumor growth. AJNR Am J Neuroradiol 1993;14:119-22.
4Okuchi K, Hiramatsu K, Morimoto T, Tsunoda S, Sakaki T, Iwasaki S. Astrocytoma with widespread calcification along axonal fibres. Neuroradiology 1992;34:328-30.
5Tashiro Y, Kondo A, Aoyama I, Nin K, Shimotake K, Tashiro H, et al. Calcified metastatic brain tumor. Neurosurgery 1990;26:1065-70.
6Tomita T, Larsen MB. Calcified metastases to the brain in a child: Case report. Neurosurgery 1983;13:435-7.