Kimura's Disease of the Orbit Successfully Treated with Radiotherapy Alone: A Case Report
A 28-year-old male presented to the Department of Ophthalmology in February 2006 with a history of blepharoptosis, exophthalmos, a reduction of visual acuity as well as a visual field defect in the right eye. The eyesight of the right eye was 0.07 and that of the left eye was 1.2. Inferior hemianopsia with a scotoma in the center was shown by the Goldmann perimetry. A relative afferent pupillary defect (RAPD) in the right eye was detected. Double vision and disturbance of the lateral gaze in the right eye were also pointed out. A mass on the right side of the neck had been observed 19 years earlier and the patient had been pathologically diagnosed as having Kimura's disease. The diagnosis of a tumor of the right orbit was made based on clinical and MRI findings (fig. ).\nBlood tests showed peripheral blood eosinophilia (15%; normal ∼6%) and elevated serum immunoglobulin E (IgE: 4,470 IU/ml; normal ∼170 IU/ml). The total leukocyte count was 6,300/mm3. A differential white blood cell count performed at that time showed 56% neutrophils, 23% lymphocytes, 15% eosinophils and 6% monocytes.\nA biopsy of the mass of the right orbit was performed by a neurosurgeon. A histological examination of the hematoxylin- and eosin-stained sections of the resected mass revealed a proliferation of the fibrous connective tissue and small vessels with an infiltration of the lymphocytes and eosinophils. There was no evidence of lymphoid follicle growth or malignancy, leading to a pathological diagnosis of Kimura's disease after considering the blood test results (fig. ).\nA neurosurgeon highly recommended radiotherapy and consulted a radiation oncologist. Radiation therapy was started in May 2006. Irradiation with 21.6 Gy was administered to the tumor bed in a single dose of 1.8 Gy in 5 weekly fractions via a high-energy linear accelerator (6-MV X-ray). A single anterior oblique portal was used to avoid radiation exposure of the right lens (fig. ). Lens protection was not used during radiotherapy. Eye drops for radiation-induced conjunctivitis and an ointment to treat radiation-induced dermatitis were also not prescribed. The tumor gradually diminished and ultimately disappeared. Four months after the completion of radiotherapy, the eyesight of the right eye was 1.5, which was the same as that of the left eye, and an improvement of the inferior hemianopsia as well as the disappearance of the scotoma in the center were demonstrated by the Goldmann perimetry. Improvements in the exophthalmos, double vision and a RAPD of the right eye were achieved. The irradiated right eye ball did not develop dry eye syndrome or a cataract. There was no evidence of radiation-induced dermatitis or radiation neuropathy. Neither tumor regrowth nor late complications were detected up to 84 months after radiotherapy (fig. ). Both the elevated serum IgE level and eosinophilia gradually decreased. The serum IgE level was 470 IU/ml 84 months after radiotherapy and the peripheral eosinophil level was 7.9% in June 2013.