To the Editor.—
We appreciate the opportunity to reply to the letter from Drs. Cohen and Minkin. In our view, unsolved nosologic problems present a challenge for further study rather than a mandate for the abandonment of attempts at rational classification. The apparent sameness of amyloid substance in the various forms of amyloidosis by no means implies the sameness of all disease states in which there is amyloid deposition. The possibility of renal involvement in both primary and secondary systemic amyloidosis hardly proves the identity of these conditions.We did not make the statement that systemic amyloidosis does not occur in patients with lichen amyloidosus. We did state that in our material and in the literature we could find no patient with the clinicopathologic picture of lichen amyloidosus associated with any form of systemic amyloidosis. We recognize the theoretical possibility that the fortuitous association of lichen amyloidosus and systemic amyloidosis