Supplement Article |
PP3. ERDHEIM-CHESTER DISEASE: YET ANOTHER MIMIC OF POLYMYALGIA RHEUMATICA AND GIANT CELL ARTERITIS?
Department of Rheumatology, Southend General Hospital, Southend on Sea, Essex, UK
Background: Erdheim-Chester Disease is a rare non-langerhans cell histiocytosis. First described in the 10th Century, there are only 60 cases in the literature. It can present with bone pain, visual field loss, pituitary failure and lower limb claudication. Prognosis is approximately two years from diagnosis.
We present the case of a 67 year old man whose symptoms were considered classical of polymyalgia rheumatica. He responded to steroid therapy initially but re-presented with eye symptoms thought to be caused by giant cell arteritis.
Methods: He had initially presented to a rheumatologist three years earlier with generalised myalgia, stiffness and cramps, associated with marked acute phase response and iron-deficiency anaemia. A diagnosis of polymyalgia rheumatica was made and an oral steroid was commenced with some improvement. Gastrointestinal and haematological investigations did not identify any pathology to account for the anaemia.
He re-presented with left-sided visual field loss associated once again with an acute phase response and was treated with high dose steroids pending temporal artery biopsy, which was negative.
On presentation to us, he had marked xanthelasmata and xanthomatous lesions over his cheeks. Systems examination including musculoskeletal examination was unremarkable. His blood tests once again revealed a marked acute phase response and, of note, normal fasting serum lipid concentrations.
Results: Plain radiography of his long bones revealed widespread sclerotic lesions. His bone scan showed symmetrical uptake in the meta- and diaphyses of his long bones. Bone biopsy revealed sclerotic bone laden with foamy macrophages, which stained CD68-positive but negative for s-100 and CD1a. A diagnosis of Erdheim-Chester Disease was made.
MRI revealed retro-orbital infiltrates causing optic nerve compression. Periaortic and renal involvement were seen on CT imaging of the abdomen. PET scan only showed disease behind the left eye and in the long bones. Local radiotherapy to both orbits was performed to protect his vision. Systemic therapy was commenced initially with intravenous steroid and pulsed cyclophosphamide. Treatment continues with lower dose oral steroid and infliximab. His symptoms have improved, his inflammatory markers have reduces and he has not developed any cardio-respiratory involvement at this stage.
Conclusions: This case illustrates a rare mimic of polymyalgia and giant cell arteritis, though the lack of complete response of steroid, the xanthomata and sclerotic bone all suggest an alternative cause.
PET scanning was used for the first time and helped tailor therapy to metabolically active sites of disease.
We propose that anti-TNF agents are appropriate therapy to control progression of this disease.