Primary Orbital Hemangiopericytoma: An Unusual Cause of Unilateral Proptosis

Abstract

Painless unilateral proptosis is a frequent manifestation of numerous orbital neoplastic and non neoplastic processes. Various mesenchymal tumours of both fibrohistiocytic and vascular origin are well-described causes. Hemangiopericytomas (HPC) are rare vascular tumours which can infrequently involve the orbit and their incidence is estimated to be 0.8% to 3% of primary orbital tumours 1,2 . We herein report a new case of orbital HPC revealed by unilateral proptosis in a 38-year-old man. Our aim was to highlight the clinicopathological and radiological features of this rare neoplasm with review of the current literature. CASE REPORTA 38-year-old previously healthy man, presented with a onemonth history of rapid expanding intra-orbital mass resulting in painless proptosis of the left eye. On admission, ophthalmologic examination revealed severe left eye proptosis (grade III). A palpable mass in the left orbit was protruding out of the palpebral fissure (Figure 1). It was irreductible, non-tender and nonpulsatile. The conjunctiva was chemotic and there was marked ulcerative keratitis. The visual acuity was 0 / 10 in the affected eye and ocular movements were restricted in all directions. The contralateral eye was within normal limits. Computed tomography (CT) scan of the orbital region (Figure 2) revealed a 87 x 54 x 32 mm, well-circumscribed mass within the intraconal space of the left orbit extending along the optic nerve and homogeneously enhanced after intravenous administration of contrast medium. Magnetic resonance imaging (Figure 3) showed a soft tissue mass iso-intense on T1-weighted images and hypo-intense on T2-weighted images. Laboratory tests and chest radiograph were within normal limits. An incisional biopsy of the intra-orbital mass was performed but was difficult to realize due to excessive haemorrhage. Histological examination of the tiny biopsy specimen obtained, established an initial diagnosis of an undifferentiated sarcoma. Orbital exenteration was carried out due to the infiltrative and highly vascular nature of the tumour.Macroscopically, the exenteration specimen measured 130 x 120 x 105 mm. A small atrophic globe at the anterior aspect of the specimen did not appear invaded by the tumour. The cut section of the mass showed a firm greyish white tumour. The eyelids were not infiltrated by the tumour. Histological examination of the surgical specimen showed a hypercellular neoplasm predominantly composed of randomly oriented polygonal and rounded cells with ill-defined cytoplasm

A rare sinonasal tumour with orbital manifestation: glomangiopericytoma

“…Orbital involvement of such tumor is exceedingly rare and their incidence is estimated to be 0.8% to 3% of primary orbital tumors. 16 It most commonly have an indolent growth pattern but a small cluster may exhibit aggressive behavior or metastasis. Complete excision is the treatment of choice.…”