[Two cases of orbital myositis with monoclonal gammopathy of undetermined significance].

PURPOSE: We report two cases of idiopathic orbital myositis with monoclonal gammopathy.

CASE: Case one was a 47-year-old man, who had bilateral swelling of the extraocular muscles and impairment of the left optic nerve. Case two was a 27-year-old woman, who had bilateral proptosis. An immunological test showed that both patients had monoclonal gammopathy, and they were diagnosed as having monoclonal gammopathy of undetermined significance(MGUS).

RESULTS

In case one, the patient achieved remission with steroid pulse therapy followed by administration of high doses of a steroid. In case two, because of repeated recurrence, the patient was treated with steroid pulse therapy and then radiation therapy to achieve final remission.

CONCLUSION

We need to pay attention in the diagnosis of orbital myositis to distinguish MGUS. Such patients have an atypical clinical course and are resistant to ordinary steroid therapy.