‘What lies Beneath’ A Case Study.
Flood RM, Kane D, Mullan RM.
Rheumatology Department, Tallaght University Hospital.
A 59 year old gentleman presented to Rheumatology in February 2019 with a four month history of 2-hour early morning stiffness in the hands, an inability to make a clenched fist, occasional Raynaud’s phenomenon, but no other symptoms of connective tissue disease. On examination, there was clear evidence of skin tightening extending to the forearms, with sclerodactyly and bilateral elbow flexion contractures due to skin tethering. Facial telangiectasias and a reduced oral aperture were also present, consistent with a sclerodermatous appearance. Abdominal examination revealed a violaceous livedoid discolouration of the anterior trunk. Lower limb examination revealed tightening of the skin from the feet to the lower shins. There was no evidence of joint synovitis and there were no other features of connective tissue disease.
Blood tests showed normal full blood count, renal, liver and bone profiles. Erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) were elevated at 63 & 34 respectively. Immune screen, including antinuclear antibody (ANA) rheumatoid factor (RF), anti-citrullinated protein (CCP) and complement C3 C4 were negative. Serum protein electrophoresis revealed a monoclonal gammopathy IgG lambda band with paraprotein of 8g/L.
A clinical diagnosis of Amyloid Elastosis secondary to subcutaneous light-chain amyloid deposition was made. He was referred to haematology, where a fat-pad biopsy with Congo Red stain confirmed the diagnosis.
Bone marrow showed a minor plasmacytosis of < 10% and to date there is no evidence of organ-related amyloidosis. A skin biopsy, to confirm the cutaneous features of amyloid accumulation around elastin fibres on electron microscopy is awaited. The patient was been urgently referred to the UK national amyloidosis centre for SAP scintigraphy and advice on ongoing management.
Amyloid Elastosis is a rarely reported scleroderma mimic,  with two previous case reports in the literature;   one of which rapidly progressed to early death due to systemic amyloidosis at the time of diagnosis. In this case, it is hoped that prompt diagnosis, prior to the advent of systemic amyloidosis complications will lead to an improved long-term outcome. Treating rheumatologists should be aware of this unusual scleroderma mimic to ensure earlier referral for appropriate specialist management.