Probable Immunoglobulin Subtype-G4–Related Disease in the Head and Neck from Foreign Body Injection: A Case Report

Background: Immunoglobulin subtype G4–related disease (IgG4-RD) is a fibroinflammatory disease of unknown etiology which may present with many manifestations, with reported cases involving nearly every organ system. IgG4-RD is a newly recognized disorder, particularly in the head and neck region. Its association with foreign bodies is also not established, with there being no reported cases in the literature at this time.

Clinically, IgG4-RD presents as tumor-like lesions which may arise in multiple parts of the body. The cardinal histopathological findings of IgG4-RD are as follows: (1) dense lymphoplasmacytic infiltrate rich in IgG4, (2) storiform fibrosis, and (3) obliterative phlebitis. Immunohistochemistry methods are also important, with a raised IgG4+ plasma cell count/high powered field and IgG4/IgG ratio > 40% being highly suggestive of IgG4-RD. A raised serum IgG4 level, though not specific, is also suggestive. The general treatment approach to IgG4-RD is immunosuppression with corticosteroid therapy.

Materials and Methods: A 58-year-old woman presented to our center in 2011 with a 5-year history of persistent left facial pain, xerophthalmia, blurred vision, and trismus. The patient's medical history was significant for left-sided temporomandibular joint (TMJ) reconstruction in 2000 with concurrent silicone injection into the joint. She describes having symptoms starting in 2007. Physical examination reveals left-sided proptosis, and periorbital edema. The remainder of her examination was noncontributory.

MR imaging revealed a lesion of the left infratemporal fossa, extending to the left masticator, buccal space, maxillary sinus, and orbit, measuring 5 cm in largest dimension. During her work-up for this lesion, tissue biopsies of the left orbit and maxilla were performed. Biopsies demonstrated the cardinal histopathological features of IgG4-RD as described earlier.

Immunohistochemistry showed that tissue IgG4/IgG ratio was > 30%, and the patient's IgG4 serum markers were within normal limits. The patient was given a trial of 40 mg prednisone for 2 weeks, and responded well with the reported resolution of her symptoms.

Discussion: While there are several case reports discussing IgG4-RD disease in the head and neck region, this is the first reported case of IgG4-RD potentially precipitated by a foreign body, in this case silicone injected into the TMJ. The pathogenesis and etiology of IgG4-RD is still not fully elucidated, but allergic and reactive inflammatory reactions have been implicated in the disease process. This is a possible mechanism for the etiology for our patient's disease as the IgG4-RD lesion is located at and around the site of the TMJ reconstruction.

On the basis of previously published diagnostic criteria and the findings of investigations aforementioned, this patient was classified as probable IgG4-RD. The patient also responded well to corticosteroid therapy, typical of IgG4-RD. Taking together the imaging, history of disease, and histopathological results, this case report should raise the idea of reactive foreign bodies as a causative agent for IgG4-RD. This case report should be informative for the Head and Neck Surgeon as the incidence and occurrence of this disease process is on the rise.