Radiological features of IgG4-related disease in the head, neck, and brain

Immunoglobulin (Ig) G4-related disease is a recently designated benign clinical entity histopathologically characterized by sclerosing inflammation and infiltration of numerous IgG4+ plasma cells that affects multiple organs. The purpose of this study is to characterize the imaging findings of patients with histopathologically proven IgG4-related disease in the head, neck, and brain.

A total of 17 patients (15 males, 2 females; mean age, 66.1 ± 7.4 years) with histopathologically proven IgG4-related disease in the head, neck, and brain were identified in two hospitals between January 2004 and December 2010. Imaging findings were retrospectively reviewed, with particular attention to the location and number of lesions, internal architecture, enhancement patterns, presence of vascular occlusion or compression, and changes in adjacent bones.

The lesions, presented as either enlarged gland(s), or focal, localized nodules/masses, were distributed in the lacrimal gland (n = 7), the parotid gland (n = 14), the submandibular gland (n = 10), the pituitary gland (n = 2), skull base dura mater (n = 2), and the pterygopalatine fossa (n = 3). All lesions were well-defined and iso- to hypointense on T2-weighted magnetic resonance images and showed homogeneous enhancement. No lesion showed vascular occlusion or compression. Bones adjacent to the lesions showed remodeling (erosion or sclerosis) without signs of destruction (n = 6). Four patients had lesions involving multiple areas which extended along the trigeminal nerve, accompanied by expansion of neural foramina along their courses, with no signs of bone destruction.

Sites of predilection for IgG4-related disease in the head, neck, and brain include the lacrimal, salivary, and pituitary glands. Recognition of the typical radiological features of IgG4-related disease, such as well-defined lesion borders, T2 hypointensity, homogeneous and gradual enhancement pattern, absence of vascular occlusion or compression, and presence of bone remodeling without destruction, may be of help in the diagnosis of this benign clinical entity.