DOI: 10.33962/roneuro-2022-053 Cerebello Pontine Angle Hemangiopericytoma - an aggressive tumour needs aggressive management. A case report Abhijit Verma, Vijay Kumar Gupta, Sanjeev Attry, Qamar Siddiqi, Shashi Singhavi Romanian Neurosurgery (2022) XXXVI (3): pp. 311-314 DOI: 10.33962/roneuro-2022-053 www.journals.lapub.co.uk/index.php/roneurosurgery Cerebello Pontine Angle Hemangiopericytoma - an aggressive tumour needs aggressive management. A case report Abhijit Verma1, Vijay Kumar Gupta1, Sanjeev Attry1, Qamar Siddiqi1, Shashi Singhavi2 1 Department of Neurosurgery. NIMS University, Jaipur, INDIA 2 Department of Pathology. SMS Medical College, Jaipur, INDIA ABSTRACT Background: CP angle Hemangiopericytoma are rare tumors. Pre-operative suspicion and gross total excision are key for better management due to their aggressive nature. Case presentation: 18-year-old male presented with signs of progressive brainstem compression. Contrast MRI showed a polycystic enhancing SOL in the right CP angle region compressing the brain stem and cerebellar lobe. Operated with histopathology and IHC indicating it to be a Hemangiopericytoma. Conclusions: Hemangiopericytoma being an aggressive tumour with a high rate of recurrence compared to other common tumours at CP angle, complete resection with definitive pathological diagnosis and radiotherapy are needed for a better outcome. BACKGROUND Hemangiopericytomas (HPCs) constitutes <1% of primary brain tumors. Mostly supra tentorial and dural based. Rare in Cerebello pontine angle (CPA), mimics meningioma radiologically, but because most are grade 2 or grade 3, this aggressive nature makes their pathological differentiation important. [2,3,4,5,6,7,8,9] We describe here an unusual case of CPA hemangiopericytoma presenting with brainstem and cerebellar signs CASE PRESENTATION An 18-year-old male presented with chief complaints of disequilibrium, Progressive weakness all 4 limbs (left>right), slurring of speech, and dysphagia for liquid for 2 months. On admission, his neurological examination revealed a left facial paresis(Hunt & Hess grade 3) with weak gag reflex and uvula deviated to right and asymmetrical palatal arches(left 9th and 10th cranial nerve paresis), and left side weakness Keywords hemangiopericytoma, cerebello pontine angle, cystic enhancing tumor, CP angle meningioma, IHC Corresponding author: Abhijit V. NIMS University, Jaipur, India draverma09@gmail.com Copyright and usage. This is an Open Access article, distributed under the terms of the Creative Commons Attribution Non–Commercial No Derivatives License (https://creativecommons .org/licenses/by-nc-nd/4.0/) which permits non- commercial re-use, distribution, and reproduction in any medium, provided the original work is unaltered and is properly cited. The written permission of the Romanian Society of Neurosurgery must be obtained for commercial re-use or in order to create a derivative work. ISSN online 2344-4959 © Romanian Society of Neurosurgery First published September 2022 by London Academic Publishing www.lapub.co.uk http://www.lapub.co.uk/ 312 Abhijit Verma, Vijay Kumar Gupta, Sanjeev Attry et al. more than right with increased tone with left cerebellar signs present, suggesting the presence of the Millard-Gubler syndrome. Head CT scan and an MRI of the brain demonstrated a solid cystic enhancing 2.8×3.5 cm sized right CPA lesion compressing brain stem with no internal acoustic meatus extension (Fig. 1). Figure 1. (A)Post-contrast magnetic resonance imaging of the brain in coronal views showing a cystic right cerebellopontine angle tumor with dural enhancement (dural tail sign); (B) T2 weighted image showing peritumoral CSF cleft; (C) T1 weighted image showing hyperintese nodule with septations in tumor. As tumor was solid cystic with enhancement a diagnosis of cystic schwannoma was made with differential being pilocytic astrocytoma and hemangioblastoma, cystic meningioma. A suboccipital retrosigmoid approach was attempted. During surgery, the tumor was solid and cystic, soft to firm, greyish pink, was suckable highly vascular, capsule was attached to cranial nerves passing in left cp angle with dural attachment superiorly . Tumor was not extending to or coming out from internal auditory canal . It was removed in parts by Cavitron Ultrasonic Surgical Aspirator (CUSA). Somatosensory evoked potentials, brainstem auditory evoked responses, and intraoperative facial nerve monitoring were used to minimise the damage intraoperatively. Figure 2. Post operative CT of Patient showing decompression of cystic part and a small residual attached to the brain stem. The patient had CSF discharge from tissue drain more than 100ml on 3rd post op day for which lumbar drain was inserted and tissue drain removed on following day. Surgical wound healed and lumbar drain removed on day 5. No leak or pseudomenigocoele formation. Patient discharged on 8th post op day without fresh neurological deficit and improved cerebellar and brain stem signs. The histopathology sections revealed moderately cellular neoplasm with closely opposed cells with round nuclei arranged in a haphazard pattern with limited intervening stroma. Nuclei are oval to spindle with dense chromatin and scanty cytoplasm. There was mild nuclear atypia with mitotic activity (<5/HPF). Cyst formation also seen. There was numerous slit like vascular spaces. Vimentin CD34 and CD99 are positive with STAT-6 strongly nuclear positive. Ki-67 is less than 5%. Immunomarkers favoured a grade 2 hemangiopericytoma. While negative for EMATLE, SOX10. (Fig. 3, Fig. 4, Fig.5, Fig.6). Figure 3. Photomicrographs of the tumor specimens showing. A: Diffuse sheets of relatively uniform population of cells interspersed by staghorn vascular channels (H&E, original magnification, ×10). B: Round to oval cells with finely dispersed nuclear chromatin and moderate cytoplasm and no signs of anaplasia (H&E, original magnification, ×20). H&E, haematoxylin and eosin. Figure 4. Immunohistochemical staining showing diffuse positivity with CD34 (original magnification, ×100). 313 Cerebello Pontine Angle Hemangiopericytoma Figure 5. CD 99 STAINING (oil immersion; original magnification ×1000). Figure 6. STAT 6 STAINING (original magnification ×100) Metastatic workup including CT of the chest/abdomen/pelvis did not reveal any evidence of extracranial HPC. Adjunctive radiation therapy was advised but he was lost to follow up since a month post-surgery. DISCUSSION HPCs are rare, and are aggressive neoplasms that arise from the pericytes of Zimmerman, which are contractile spindle cells surrounding capillaries and post capillary venules [4]; and most often involve the musculoskeletal system and skin [1].Intracranial HPCs constitute just 0.4% of all intracranial tumors [10] and approximately 2% to 4% of all meningeal tumors [5]. Immunohistochemistry has major role in diagnosis of HPC. It also helps in differentiation between meningioma and HPC, where HPC is positive with CD34, CD99 and STAT-6 [5]. In the present case, the morphological features were distinctive enough to place the lesion in the category of an HPC. Fairly uniform cellularity of the tumor and the high mitotic activity was more supportive of this lesion being labelled as grade II HPC instead of a cellular SFT The similarity between meningioma and HPC is limited to radiology and gross morphology. In fact, with a mean survival of 84 months from the time of initial diagnosis [5], a local recurrence rate as high as 91% and a 15-year risk of distant metastasis approaching 70%; intracranial HPCs harbour one of the most aggressive biological/clinical behaviours [16]. In present scenario gross total resection followed by radiotherapy is standard of care. Radiation therapy has in fact extended the mean time of local recurrence from 34 to 75 months, and the survival from 62 to 92 months [1]. CONCLUSIONS In conclusion, HPC being aggressive tumor with high rate of recurrence and metastasis, it should be included as a differential diagnosis in dural Based extra axial CPA tumors in age-appropriate cases. A high index of suspicion on radiology imaging is essential to plan for complete excision, and role accurate histopathological diagnosis can’t be overemphasised. As postoperative recurrence seems unavoidable, long-term follow-up with serial imaging should be considered in all cases. REFERENCES 1. Kumar N, Kumar R, Kapoor R, et al. Intracranial meningeal hemangiopericytoma: 10 years experience of a tertiary care Institute. Acta Neurochir (Wien) 2012;154:1647–1651. [PubMed] [Google Scholar] 2. Molnar P, Nemes Z. Hemangiopericytoma of the cerebello-pontine angle. Diagnostic pitfalls and the diagnostic value of the subunit A of factor XIII as a tumor marker. Clin Neuropathol. 1995;14:19–24. [PubMed] [Google Scholar] 3. Mallucci CL, Ward V, Carney AS, O'Donoghue GM, Robertson I. Clinical features and outcomes in patients with non-acoustic cerebellopontine angle tumours. J Neurol Neurosurg Psychiatry. 1999;66:768–771. [PMC free article] [PubMed] [Google Scholar] 4. Alén JF, Lobato RD, Gómez PA, et al. Intracranial hemangiopericytoma: study of 12 cases. Acta Neurochir 314 Abhijit Verma, Vijay Kumar Gupta, Sanjeev Attry et al. (Wien) 2001;143:575–586. [PubMed] [Google Scholar] 5. Tashjian VS, Khanlou N, Vinters HV, Canalis RF, Becker DP. Hemangiopericytoma of the cerebellopontine angle: a case report and review of the literature. Surg Neurol. 2009;72:290–295. [PubMed] [Google Scholar] 6. Cho JM, Kim SH, Kim SH, Lee KS, Chang JH. Recurred cerebellopontine angle haemangiopericytoma 5 years after stereotactic radiosurgery. Clin Neurol Neurosurg. 2011;113:931–933. [PubMed] [Google Scholar] 7. Zeng J, Ogera P, Benardete EA, Nicastri AD, Rao C. Cellular solitary fibrous tumor (hemangiopericytoma) with anaplasia at cerebellopontine angle--a case report. Pathol Res Pract. 2012;208:493–496. [PubMed] [Google Scholar] 8. Salunke P, Futane S, Gupta K, Vasishta RK. Cerebello- pontine angle hemangiopericytoma: an orphan differential diagnosis. Clin Neurol Neurosurg. 2013;115:1184–1186. [PubMed] [Google Scholar] 9. Teoh JW, Goh BS, Shahizon Azura MM, Siti Aishah MA, Nor Hafliza MS. An unexpected lesion in cerebellopontine angle: hemangiopericytoma. Med J Malaysia. 2014;69:146–147. [PubMed] [Google Scholar] 10. Melone AG, D'Elia A, Santoro F, et al. Intracranial hemangiopericytoma--our experience in 30 years: a series of 43 cases and review of the literature. World Neurosurg. 2014;81:556–562. [PubMed] [Google Scholar] 11. Soyuer S, Chang EL, Selek U, McCutcheon IE, Maor MH. Intracranial meningeal hemangiopericytoma: the role of radiotherapy: report of 29 cases and review of the literature. Cancer. 2004;100:1491–1497. [PubMed] [Google Scholar] 12. Zhou JL, Liu JL, Zhang J, Zhang M. Thirty-nine cases of intracranial hemangiopericytoma and anaplastic hemangiopericytoma: a retrospective review of MRI features and pathological findings. Eur J Radiol. 2012;81:3504–3510. [PubMed] [Google Scholar] 13. Liu L, Yin B, Geng DY, Li Y, Zhang BY, Peng WJ. Comparison of ADC values of intracranial hemangiopericytomas and angiomatous and anaplastic meningiomas. J Neuroradiol. 2014;41:188–194. [PubMed] [Google Scholar] 14. Chen H, Zeng XW, Wu JS, et al. Solitary fibrous tumor of the central nervous system: a clinicopathologic study of 24 cases. Acta Neurochir (Wien) 2012;154:237–248. discussion 248. [PubMed] [Google Scholar] 15. Louis DN, Ohgaki H, Wiestler OD, et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 2007;114:97–109. [PMC free article] [PubMed] [Google Scholar] 16. Erdag G, Qureshi HS, Patterson JW, Wick MR. Solitary fibrous tumors of the skin: a clinicopathologic study of 10 cases and review of the literature. J Cutan Pathol. 2007;34:844–850. [PubMed] [Google Scholar] 17. Chamberlain MC, Glantz MJ. Sequential salvage chemotherapy for recurrent intracranial hemangiopericytoma. Neurosurgery. 2008;63:720–726. author reply 726-7. [PubMed] [Google Scholar] 18. Angelina Graziella Melone et al. Intracranial hemangiopericytoma--our experience in 30 years: a series of 43 cases and review of the literature. World Neurosurg. Mar-Apr 2014;81(3-4):556-62.