[Macular amyloidosis].

Fifty-five patients with presumptive macular amyloidosis were investigated for the presence of amyloid in dermal tissue. In twenty-six of these patients the diagnosis could be confirmed by the demonstration of amyloid deposits by optical and/or electron microscopy. In this paper attention is called to the frequency of oligosymptomatic forms of macular amyloidosis, which are often overlooked in spite of the usual existence of itching. These inconspicuous forms are termed "minor macular amyloidosis", and they consist of tenuous brown macules on the upper back, irregularly interspersed with the normal skin and with speckles of whitish discoloration. The diagnosis must be verified by the finding of dermal deposits of amyloid. For that purpose the electron microscopy is a much more reliable procedure than conventional methods or thioflavine T.