Orbital involvement in Waldenström's macroglobulinemia: ultrasound, computed tomography and magnetic resonance findings.

A case of orbital involvement in Waldenström's macroglobulinemia is presented. Orbital echography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed and revealed a retrobulbar mass of the right orbit. Ultrasonography suggested a lymphoid orbital tumor. A CT scan was nonspecific, but helpful in exactly locating the tumor and excluding bony lesions. Signal intensity patterns of MRI were characterized by a low intensity on T1- and T2-weighted images. A marked enhancement of the tumor was evident after intravenous injection of a paramagnetic contrast agent (gadolinium-DTPA). Although the definite diagnosis could only be established by means of an ultrasound-guided fine-needle aspiration biopsy, MRI in connection with the history of our patient strongly suggested a diagnosis of orbital lymphoma in Waldenström's disease.