Candida Septic Arthritis with Rice Body Formation: A Case Report and Review of Literature
A 74-year-old male patient presented with a complaint of persistent pain and swelling of the right shoulder for six months. According to previous medical records from outside the hospital, he had a history of surgery on his right shoulder at another tertiary hospital 18 months ago, and the pathogen identified at that time was Candida species. In addition, he received intravenous and oral antifungal medication (fluconazole) for one month after the operation. He had no history of trauma, or any other medical problems. On physical examination, localized swelling around the shoulder and limited range of motion were observed.\nLaboratory examination revealed an elevated erythrocyte sedimentation rate (106 mm/hr) and a high sensitivity C-reactive protein level (4.18 mg/dL). The results of blood examination showed increased counts of eosinophils (7.3%) and monocytes (12.1%), whereas the white blood cell count was within the normal limit (8080 mm3).\nPlain radiography of the shoulder showed small bone erosion at the subchondral portion of the glenoid and humeral head (). Subacromial spur and superior migration of the humeral head, suggestive of a rotator cuff tear, along with degenerative osteophytes and joint space narrowing of the glenohumeral joint were noted. Subsequently, magnetic resonance imaging (MRI) of the shoulder was performed with intravenous gadolinium enhancement. 3.0T MRI (Skyra, Siemens, Erlangen, Germany) showed joint effusion and massive distension of the subacromial-subdeltoid bursa and subcoracoid bursa, with innumerable rice bodies inside, which were isointense to muscle on T1-weighted images, and slightly hyperintense on fat-suppressed proton-density weighted and T2-weighted images (). The joint and bursal spaces communicated through a massive full-thickness tear of the supraspinatus tendon. Diffuse and some nodular synovial thickening with enhancement was noted on post-gadolinium fat-suppressed T1-weighted images (), however, the rice bodies did not show enhancement. Multifocal bone erosions were observed at the humeral head, glenoid, inferior surface of the acromion and distal clavicle. Associated bone marrow edema around the erosions of the humeral head and glenoid were visualized on fat-suppressed T2-weighted images, suggesting osseous involvement of the inflammation. In addition, multiple enlarged lymph nodes were identified in the axillary area. Because he had a history of surgery due to fungal infection, the likely diagnosis was recurrent septic arthritis of fungal origin. Differential diagnoses included tuberculous arthritis and other chronic inflammatory arthritis, such as rheumatoid arthritis, because of the unusual rice body appearance on MRI. Aspiration of joint fluid was performed in the outpatient clinic before admission. Gram-staining under oil immersion detected yeasts, and culture of the fluid identified Candida parapsilosis. No bacteria were observed on the Gram-stain and fluid culture. Polymerase chain reaction for Mycobacterium tuberculosis (TB-PCR) and cultures for mycobacteria were also negative. Surgical exploration with drainage, bursectomy, and debridement was performed. Numerous rice bodies of a few millimeters in size were found in the joint and bursae (), and inflammatory changes were observed in periarticular soft tissue. Histopathologic examination of the thickened bursa and periarticular soft tissue revealed chronic active inflammation with fibrin deposition and dystrophic calcification, without evidence of pannus or granuloma formation (). The rice bodies were mainly composed of fibrin with some chronic inflammatory cells, hemorrhagic infarct, and dystrophic calcification (). Candida parapsilosis was also detected after the tissue culture. Staining of tissue sections for acid-fast bacteria and tissue cultures for bacteria and mycobacteria were all negative. The patient did not have any other clinical or radiologic features of rheumatoid arthritis, therefore, serological testing for inflammatory arthritis was not required. He received intravenous treatment with fluconazole, and recovered from swelling and regained range of motion of his shoulder.