A. Rausing et U. Rosen, BLACK CARTILAGE AFTER THERAPY WITH LEVODOPA AND METHYLDOPA, Archives of pathology and laboratory medicine, 118(5), 1994, pp. 531-535
Citations number
12
Categorie Soggetti
Pathology,"Medical Laboratory Technology","Medicine, Research & Experimental
A study was undertaken of 14 autopsy cases with pigmented rib cartilag
e. Twelve of these patients had been treated with levodopa because of
Parkinson's disease for at least 6 years, and two had been treated wit
h methyldopa because of essential hypertension for 19 years. Thirty-tw
o percent of the autopsy cases of Parkinson's disease during a recent
70-month period demonstrated pigmented rib cartilage. Only one of them
also demonstrated pigmentation of intervertebral disks. No abnormal p
igmentation was seen in other sites. The pigment was located in the hy
aline matrix of rib cartilage and in necrotic chondrocytes. Levodopa w
as chromatographically demonstrated within the cartilage of patients w
ith Parkinson's disease, but in both pigmented and unpigmented sites.
It is speculated that a pigmented drug metabolite is bound preferentia
lly to the matrix of rib cartilage. Dopa pigmentation only occurs in c
artilage and differs in several respects from endogenous and exogenous
ochronosis. It appears to be harmless but irreversible.