Cutaneous amyloid elastosis is a rare presentation of amyloidosis. Only 5 cases have been reported since 1985; 4 in the setting of various presentations of systemic amyloidosis and 1 primary cutaneous localized amyloid elastosis. We report here an additional case, initially misdiagnosed as pseudoxanthoma elasticum (PXE).
CASE REPORTA 69-year-old woman was referred for fatigue, dyspnoea on exertion and skin changes. Five years earlier, papules on several aspects of the neck had appeared suddenly (over a single night according to the patient), and had quickly extended following oedematous episodes. The patient's medical history included myocardial infarction, hypertension and concentric hypertrophic cardiomyopathy, osteoporosis, hypothyroidism and depression. Dermatological examination revealed diffuse but subtle, whitish or skin-coloured papules, located mainly in cervical, flexural, periumbilical, abdominal and lumbar areas, but also on the gingiva and the inner aspect of the lower lip. Debilitating pruritus was present, as well as hand paraesthesia and vague aches. There was no macroglossia. Cardiac auscultation revealed a systolic murmur (3/6) related to aortic valve stenosis. On echocardiography, septal hypertrophy with a small pericardial effusion was present. Laboratory findings showed normochromic, normocytic, aregenerative anaemia (haemoglobin 10.9 g/dl), but no leucopaenia or thrombopaenia. Renal and hepatic functions and serum calcium level were normal. There was moderate inflammatory syndrome. The beta-2-microglobulin level was high (5.25 g/l). Massive nonselective proteinuria (6-8 g/24 h) was also present. Serum protein electrophoresis revealed a high peak in gammaglobulins (15.7 g/l) with monoclonal immunoglobulin (Ig)G-λ gammopathy. Residual IgA, IgM and albumin levels were decreased. Free λ light chains were present in the urine. Brain natriuretic peptide was high (971 pg/ml -n < 100). The diagnosis of multiple myeloma was established after demonstration of 20% bone marrow infiltration with plasma cells displaying a hyperdiploid karyotype. There were no lytic bone lesions.A skin biopsy was performed, and haematoxylin and eosin (H&E) and orcein staining revealed an accumulation of dystrophic basophilic elastic fibres in the dermis. Some elastic fibres were fragmented, showing a striking "fishbone" appearance at high magnification (Fig. 1). Congo red staining was negative. Electron microscopy of a skin sample revealed an abundant microfibrillar material highly suggestive of amyloid fibrils that coated the oxytalan and elaunin fibres in the papillar dermis and the mature elastic fibres in the mid-dermis (Fig. 2). Renal biopsy demonstrated amyloidosis with amorphous deposits within tubules and arterioles. Congo red staining was positive in the kidney. The patient was treated with melphalan, dexamethasone and bortezomib. After the third injection of bortezomib, the patient developed left-side heart failure, presumably due to cardiac amyloidosis. Treatment was suspended until the heart function improved ...
