Combined clinical and computed tomographic diagnosis of orbital lymphoid tumors.

Computed tomography has made it possible to make a strongly presumptive preoperative diagnosis of orbital lymphoid tumors, particularly when the radiographic findings are analyzed in conjunction with the clinical features. Twenty-six patients (with 27 orbital lymphoid tumors) had an average age of 57 years and had painless swelling or low-grade proptosis averaging 7.5 months in duration. The computed tomographic findings were highly characteristic. Almost all of the tumors had a retrobulbar or superior orbital component. In both the coronal and axial planes, distinctive growth patterns and contourings were discovered. The lesions molded themselves to preexisting orbital structures without eroding bone or enlarging the orbit. Against the bone, globe, and muscle edges, the lesions featured smooth, sharply demarcated contours with abruptly acute or perpendicular angulations, whereas a streaky profile became apparent as they irregularly infiltrated the retrobulbar fat, reflecting involvement of microfascial structural elements. No distinguishing differences were discovered in the growth patterns of the benign and the malignant tumors.