Study sheds light on space-occupying lesions

This retrospective case series reports on the frequency of various types of orbital space-occupying lesions seen at an orbital unit over a 35-year period.

The study included medical records of 2,480 patients with orbital space-occupying lesions seen from 1976 until 2011. Of these lesions, 1,697 (68 percent) were benign and 783 (32 percent) were malignant. Benign tumors were more common in patients younger than 60 years while malignant tumors increased in frequency in patients older than 60 years.

Benign tumors were most common in the superior temporal quadrant and malignant tumors were more common in the lower inner quadrant. The most common benign lesions were dermoid cyst (14 percent) and cavernous hemangioma (9 percent). The most common malignant tumors were non-Hodgkin lymphoma (12 percent), basal carcinoma (3 percent) and orbital metastases (3 percent).

Regarding the distribution in the orbit, the most common tumors were dermoid cyst (206 cases) in the upper-outer quadrant, mucocele (155 cases) in the upper-inner quadrant, basal cell epithelioma (35 cases) in the lower-inner quadrant, cavernous hemangioma (68 cases) in the lower-outer quadrant, and meningioma (90 cases) in the central space. Most of the tumors were located in the upper-outer quadrant.

The authors found that the incidence of the different subtypes of orbital space-occupying lesions in this study was quite similar to those previously reported in literature. They say the results may assist clinicians in formulating a differential diagnosis in a patient with proptosis or other orbit-related symptoms and signs.