A well-defined Focal lesion in the cone of extraocular muscles of the eye with proptosis in a child. The diagnosis will be? (AIIMS May 2010)
Hemangioendothelioma: it is a capillary hemangioma which may present as intracranial lesion.
Cavernous hemangioma: It is a congenital lesion but manifest in adulthood only Q.
1. The capillary angioma is a tumour of early childhood. It forms a soft, bluish mass, which may involve any part of the orbit, including the eyelid. US shows it as a well-defined anterior soft lesion with small irregular echoes.
2. CDFI shows pathognomonic features with high flow within immature vessels in a hypervascularized mass.
3. Since these tumours regress either spontaneously or after steroids, CT is only indicated for tumours with retrobulbar extension.
4. Cavernous haemangioma, the commonest primary retrobulbar tumour, is a slow-growing, well-defined, rounded or oval mass consisting of large vascular spaces surrounded by a firm capsule.
5. Usually it lies within the muscle cone, displacing the optic nerve, and is well depicted by US, CT, and MRI. Phleboliths are not uncommon.
6. CT reveals a well-defined homogeneous rounded tumour, enhancing moderately after injection of intravenous contrast medium.
7. The MRI signal is rather characteristic, equal to muscle signal on T1-weighted images and marked hypersignal relative to fat on T2-weighted images. Strong but heterogeneous contrast enhancement is the rule.
8. The diagnosis may be confirmed by US, since these lesions have a specific ‘honeycomb’ US pattern of alternating weak and strong echoes, corresponding to their structure.
9. Their reflectivity is high and the attenuation is moderate.
10.Hemangioendothelioma, hemangiopericytoma and vascular leiomyoma are rare tumours, without specific radiological features, while lymphangioma is a benign diffuse tumour involving the orbit and adjacent part of the face, seen mainly in children.