Ochronosis masquerading as pigmented villonodular synovitis: a case report

Alkaptonuria is an autosomal recessive disorder of tyrosine metabolism with a Mendelian pattern of inheritance. We present a unique, clinically asymptomatic case of ochronosis, first diagnosed on histopathological examination. This case is presented for its rarity. The knowledge of the histopathological changes would help to clinch the diagnosis even when it is not suspected clinically or radiologically, as in our case. An early and appropriate diagnosis would direct conservative therapy rather than major surgeries and would also help in preventing the development of fatal complications.