A 55-year-old man with a 3-month history of numbness and tingling in his extremities presented at a hospital. After obtaining a diagnosis of seronegative arthritis, the patient underwent immunosuppressive therapy with prednisone (5 mg/day) and salazosulfapyridine (100 mg/day). However, the symptoms did not improve, and he later experienced double vision. After 10 days, the patient was referred to our university hospital. At the examination, his vital signs were stable and his general appearance was good. He complained of slight pain around his right eye and manifested a swelling and tenderness at the right periorbital area (Figure A). An ocular examination indicated diplopia in downward and rightward gazing without any obvious disturbance of eye movement. We referred the patient to an ophthalmologist, but no abnormal findings, including uveitis, were reported. Other neurological findings were inconclusive, including examination of cranial and motor nerves, and regions of the numbness and tingling on his extremities did not correspond with a dermatome. Laboratory tests for complete blood counts and serum chemistry did not show any abnormal results. Computerized tomography of the head revealed swelling of inferior and medial rectus muscle of the right eye (Figure B). Further examinations, such as interferon-gamma release assay, serum IgG4 levels, and angiotensin converting enzyme levels, were within normal range, and a definitive diagnosis could not be made. Next, we performed a biopsy of the inferior rectus muscle as a diagnostic test. Results of the pathological examination were negative for Ziel-Neelsen stain and CD138 immunohistochemical stain, excluding tuberculosis, lymphoma, and IgG4-related disease. However, hematoxylin-eosin stain revealed a typical finding of epithelial granuloma, leading to a final diagnosis of extraocular muscle sarcoidosis. Systemic investigation with positron emission tomography revealed a bilateral hilar adenopathy and inflammation of the right extraocular muscles (Figures C and D). However, there was no inflammation at the extremities. We treated the patient with prednisone at a dose of 0.5 mg/kg per day. The diplopia disappeared and tenderness and swelling of the right periorbital area subsided in 4 weeks, although numbness and tingling of his extremities remained.
We present a case of extraocular muscle sarcoidosis, which was initially diagnosed as seronegative arthritis. Lymphoma, orbital infections, and myositis associated with autoimmune diseases, such as polyangiitis and IgG4-related disease, are possible differential diagnoses, when a patient manifests with extraocular muscle involvement.1 In this case, we successfully diagnosed the patient by extraocular muscle biopsy. Sarcoidosis is a multisystem granulomatous disorder of unknown etiology that is pathologically characterized by the presence of noncaseating granulomas in involved organs. The disease progresses slowly and with latent phases, often without apparent presentations, and requires a long time to arrive at a diagnosis. An ophthalmic manifestation typically occurs at the anterior segment, such as an uveitis, whereas an extraocular muscle involvement is quite rare; coincident with only 1% of ophthalmic sarcoidosis.3, 4 However, most cases with an extraocular orbital tissue involvement have systemic sarcoidosis,5 and this patient could have been diagnosed with the disease at an earlier stage. His symptoms of numbness and tingling in the extremities could also be a manifestation of sarcoidosis. Neurologic involvement occurs in 5% to 13% of patients with sarcoidosis,2 with various manifestations, including cranial neuropathy, meningitis, polyneuropathy, mononeuritis multiplex, and small fiber neuropathy. The symptoms did not correspond to a dermatome and were not accompanied by other neurological abnormalities, which suggested the possibility of small fiber neuropathy. Sarcoidosis involves a wide variety of clinical presentations, which frequently show up and vanish as a potential diagnosis of undiagnosed cases. However, a diagnosis may be obtained by examining a crucial lesion because an entity of the disease is always present in a tissue.
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-Futoshi Nakagami, MD, PhD, Hideharu Hagiya, MD, PhD, Akane Oyama, MD, Kazuhiro Hongyo, MD, PhD, Motonori Nagasawa, MD, PhD, Hiromi Rakugi, MD, PhD
This article originally appeared in the December issue of The American Journal of Medicine.
