title: Coexistence of ankylosing spondylitis and rheumatoid arthritis.
abstract: Ankylosing spondylitis and rheumatoid arthritis share many common features. However the presence of rheumatoid factor, histologically classic rheumatoid nodules, and the histocompatibility cell wall antigen (HLA-B27) helps distinguish one from the other. Two cases are reported in which these features established the coexisting diagnoses of ankylosing spondylitis and rheumatoid arthritis.
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D011859:Radiography; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging