In cases of sero-negative rheumatoid arthritis (RA), no abnormal findings are observed on blood tests and its clinical course is favorable, compared to sero-positive RA. In the acute phase of sero-negative RA, infiltration of neutrophils may be the only pathologic finding on frozen section biopsy. Thus, it might be misdiagnosed as pyogenic arthritis. We report on a case of acute sero-negative RA misdiagnosed as pyogenic arthritis during hip surgery with review of the literature.
Arthritis ; Arthritis, Rheumatoid ; Biopsy ; Frozen Sections ; Hematologic Tests ; Hip ; Neutrophils