title: Unusual presentations of pyrophosphate arthropathy.
mesh_terms: D000368:Aged; D001168:Arthritis / Q000175:diagnosis / Q000209:etiology*; D003460:Crystallization; D003937:Diagnosis, Differential; D011756:Diphosphates / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D011756:Diphosphates