Eleven new patients with macular amyloidosis were observed during one year. Areas involved included the thighs, shins, arms, upper back, breasts, and buttocks. Typical cases exhibited moderately pruritic, symmetrically distributed, brown, rippled macules. Amyloid deposits in the papillary dermis were quantitatively and qualitatively similar to those found in lichen amyloidosus. The differential feature was a lack of epidermal hyperplasia in macular amyloidosis. Ultrastructurally, the amyloid was the same as that described in other forms of amyloidosis. Islands of amyloid were present in the papillary dermis and extended to the dermoepidermal junction. Many of these aggregates were surrounded by fibroblasts. The association of macular and lichenoid elements in some patients, and features that are similar on examination with both the light and electron microscope, suggest that macular amyloidosis and lichen amyloidosus represent the same basic disease.
Brownstein MH, Hashimoto K. Macular Amyloidosis. Arch Dermatol. 1972;106(1):50-57. doi:10.1001/archderm.1972.01620100038010