Rare Osteoarticular Involvement of Brucella Infection: Prepatellar Bursitis Presenting as A Massive Mass

The osteoarticular involvement of Brucella infection may present as arthritis, bursitis, tenosynovitis, or spondylitis. Isolated presentation of Brucella infection as bursitis is a rare occurrence. The objective of this report was to present two cases of Brucella infection presenting with isolated prepatellar bursitis as osteoarticular involvement. The initial case report concerns a 56-year-old female patient who presented with a complaint of swelling in the left knee, accompanied by minimal pain, which had been present for the previous year. The second patient was a 53-year-old male patient who presented with a complaint of painless swelling in the knee, which had first appeared two years prior and had progressively worsened. Physical examination observed swelling extending from the anterior to the lateral side of the left knee, with no erythema, warmth, or tenderness observed in both patients. Laboratory examinations revealed normal biochemical parameters, complete blood count, and erythrocyte sedimentation rate (ESR), but C-reactive protein (CRP) levels were three times higher than the cut-off value. Serological tests revealed Brucella IgG positivity. Following the investigations, surgery was planned, and through a longitudinal incision, the masses were reached and completely excised. The resected tissue’s pathological examinations revealed chronic granulomatous inflammation. In endemic regions such as the one under consideration here, Brucella bursitis should be considered in the context of isolated and suspected osteoarticular involvement, regardless of the presence of any features in the patient’s history. Clinical suspicion plays a pivotal role in the preliminary diagnosis of Brucella bursitis, guiding clinicians in the early diagnosis and effective treatment of the disease.