[P-11] Haemangiopericytoma of the pineal region: report of a rare case in unusual location
Lerpong Chaimanun1, Jaturong Khamtha1, Worakanya Thongnuch1, Kullapat Veerasarn1, Sirirat Khunvutthidee2 and Samasuk Thammachantha3
- Department of Neurosurgery, Neurological institute of Thailand (NIT), Bangkok, Thailand
- Department of Radiology, Neurological institute of Thailand (NIT), Bangkok, Thailand
- Department of Pathology, Neurological institute of Thailand (NIT), Bangkok, Thailand
Background: Intracranial hemangiopericytoma (HPC) is a rare non-meningothelial mesenchymal tumour which derives from malignant transformation of pericytes. It has been accounting for 0.4% of all intracranial tumours. Primary HPC in the pineal region has been rarely reported. Here we report a rare case of the pineal HPC.
Case Presentation: A 55-year-old female presented with one-month history of ataxia. Neurological examination revealed full motor power and intact sensation. There was absence of abnormal reflex. Cranial nerve and other physical examination were not remarkable. Magnetic resonance imaging (MRI) showed a lobulated enhancing pineal mass, which compressed tectal plate, produced mild hydrocephalus. Pineal meningioma and pineal parenchymal tumour were in the differentials. Subtotal surgical resection of the tumour showed a well-defined firm greyish white mass. Microscopic findings revealed patternless architecture of spindle cells with round to ovoid nuclei. There are stromal collagen deposition and thin-walled branching vessels. Absence of mitotic figure and necrosis. Immunohistochemistry showed diffuse and strong nuclear expression of STAT-6 in tumour cells. They were also positive for CD34, but negative for epithelial membrane antigen (EMA), somatostatin receptor-2a (SSTR-2a), glial fibrillary acidic protein (GFAP), synaptophysin, S-100, smooth muscle actin and desmin.
Discussion and Conclusion: HPC is rarely encountered in pineal region. It can mimic meningioma in both clinical and radiographic presentations. Histopathological study is the gold standard for definite diagnosis. Treatment of choice is surgical resection. Adjuvant radiotherapy reduces local recurrence in malignant HPC (mitosis > 4/10 HPFs). In conclusion, HPC is more invasive than meningioma biologically. Pathologists must be aware of HPC in this unusual location.