Abstract

A variety of space-occupying lesions may involve the orbit⁽¹⁾ and can present with a wide variety of symptoms. If they are not diagnosed early and treated immediately they can lead to loss of vision and disability.

Therefore accurate diagnosis is necessary which will help in directing the therapy. CT and MRI are the commonly used modalities. Nowadays MRI is the most commonly used modality for orbital tumor diagnosis unless there is a contraindication.

Objectives

1. To study the demographic profile of patients with orbital tumors.
2. To assess the distribution, features, localization and extent of orbital tumors by MRI.
3. To access the nature (benign / malignant) of tumor.
4. To correlate the tissue characterization by MRI with that of histopathological examination.

Materials and Methods

1. A prospective study was conducted in the departments of Radiodiagnosis, Ophthalmology, Neurosurgery, and Pathology at SCBMCH, Cuttack from March 2017 to September 2018.
2. 51 patients diagnosed as having orbital tumors by clinical examination and MRI were followed till post surgery discharge or HP result.

Results: Out of 51 patients with orbital tumors, 23 patients (45.1%) were males and females made up around 54.9% (28 patients). Around 17.6% of the patients were in the pediatric age group and the rest were adults. Our study showed that extraconal tumors 29/51(56.9%) were the commonest, followed by intraconal tumors 14/51(27.5%) and ocular tumors 8/51(15.7%). Proptosis was the commonest symptom followed by swelling in the orbit.

Overall, hemangiomas and lymphomas were the commonest orbital tumors accounting for 11.8% of the tumors each. Other tumors in decreasing order of frequency were meningiomas 5/52(9.8%), pseudotumor 5/51(9.8%), metastasis 5/51(9.8%), glioma 4/51(7.8%), adenoid cystic carcinoma 4/51 (7.8%), pleomorphic adenoma 3/51 (5.9%), two (3.9%) each of schwannoma, dermoid cyst, rhabdomyosarcoma, retinoblastoma, choroid melanoma, and one (1.9%) each of extranodalRosaiDorfmann disease, fibrous dysplasia, venous malformation.

Lymphoma was the commonest extraconal tumor accounting for 20.7% of the extraconal tumors. Hemangioma was the commonest intraconal tumor accounting for 42.8% of them. Metastases were the commonest ocular tumor accounting for 62.5% of them.

Out of 51 cases, MRI diagnosed 40 cases correctly. Out of the 11 wrongly diagnosed cases, 9 were extraconal, 2 were intraconal in location. Overall, MRI was able to correctly diagnose 78.43% of the orbital tumors. MRI was able to correctly diagnose 69% of the extraconal tumors, 85.7% of the intraconal tumors, and 100% of the ocular tumors.

Ability of MRI to detect malignancy was as follows: sensitivity 85.7% specificity 80%, PPV 75%, NPV 88.89% with an accuracy of 82.35%.

Conclusion

1. MRI is an important imaging modality which can accurately assess the distribution, features, localization, and extent of orbital tumors.
2. MRI can accurately characterize the tumor tissue in 78.43% of the orbital tumors, 69% of the extraconal tumors, 85.7% of the intraconal tumors, and 100% of the ocular tumors. Advanced MRI techniques may help in better tissue characterization.
3. MRI had an accuracy of 82.35% in detecting malignancy.

Mesh Terms: Orbital tumors, extraconal tumors, intraconal tumors, magnetic resonance imaging.