tophus

To"phus, n.; pl. Tophi. Etym: [NL.: cf. F. tophus a mineral concretion in the joint. See Toph.] [Written also tofus.] 1. (Med.) Defn: One of the mineral concretions about the joints, and in other situations, occurring chiefly in gouty persons. They consist usually of urate of sodium; when occurring in the internal organs they are also composed of phosphate of calcium. 2. (Min.) Defn: Calcareous tufa.

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