A 68 years old male patient came to the orthopedics department because of pain and swelling of the left shoulder joint. The patient developed left shoulder joint pain without obvious incentive 6 months prior, and there was no obvious shoulder joint swelling or limited shoulder joint movement at that time. He received more than 15 irregular intraarticular steroid injections in the shoulder joint at a local private hospital. The pain was significantly relieved within 1 week after each injection, but it recurred. One month prior to presentation, the patient had aggravated pain in the left shoulder joint, and the joint gradually swelled with obvious limitations of abduction and internal rotation. He had a history of fracture in his left shoulder 20 years earlier. Due to the age of the injury, the details could not be traced. No surgical treatment was performed at that time, and he recovered well. Physical examination found local swelling and tenderness in the shoulder, with limited range of motion. The patient had no fever, rheumatic disease, tuberculosis, or immunosuppressive drugs. The blood test indicated a white blood cell count of 5.43*109/L, a C-reactive protein (CRP) level of 3.27 mg/L, an erythrocyte sedimentation rate of 17 mm/h, a rheumatoid factor less than 20 IU/mL, and positive results from T-spot and TB-Ab tests.
Plain radiography (Figure 1A and B) and CT scan (Figure 1D-F) showed bone erosion at the humeral head, the subchondral portion of the glenoid and the acromion. MRI (1.5) showed uneven signal increases in the humeral head, acromion and glenoid, articular cartilage wear, massive tears of the supraspinatus, subacromial space communication with the glenohumeral joint, and subdeltoid bursa communication with the glenohumeral joint cavity. The synovium of the joint was thickened and swollen, and there were extensive "rice body-like" low T2 signal shadows filling (Figure 1G-I). The enhanced gadopentetate with meglumine scan showed obvious enhancement of the synovium in the T1 sequence, but no enhancement was found in the rice body formation inside the bursa (Figure 1J-L). 
Considering that infectious diseases needed to be ruled out and discussions about surgical procedures such as rotator cuff repair and shoulder joint replacement would have to wait, arthroscopic removal of rice bodies and subtotal bursectomy were performed. The observation channel was placed through the posterior approach, and a lot of rice bodies in yellow bursa fluid were observed to flow out (Figure 2A and B). After the lens was placed, rice bodies with a diameter of approximately 1-5 mm filled the joint cavity (Figure 2C and D). Placing the shaver through the lateral approach, the field of vision became clear after removing most of the rice bodies. We found a spontaneous rupture of the long head tendon of the biceps brachii and a large rupture in the supraspinatus; the subacromial space was connected to the joint through this rupture. Three arthroscopic approaches (posterior approach, anterior approach and lateral approach) were used to monitor and operate and to fully explore the subacromial bursal, subdeltoid bursal, the periglenoid and the anterior spaces of the subscapularis. The rice body and denatured synovial tissue were fully shaved. Postoperative MRI showed that although the swelling around the joint was obvious, there was no remaining rice body (Figure 2G and H). 
The histopathological examination of the rice body showed that it was mainly composed of fibrin without a clear tissue structure, with some small amount of tissue and cell coagulation (Figure 2E and F). A PCR test for the detection of Mycobacterium tuberculosis DNA suggested negative results, and bacterial and fungal cultures of synovial fluid suggested Candida parapsilosis infection performed by Vitek-2 (BioMerieux, France) automated system. However, peripheral blood culture showed no bacterial or fungal proliferation. Drug sensitivity test (DST) indicated that voriconazole, itraconazole, fluconazole, 5-flucytosine, and amphotericin are susceptible. Therefore, the patient received fluconazole (400 mg/qd) intravenously for 1 week, and then oral administration (200 mg/bid) to sequential therapy for 8 weeks as planned.
However, the shoulder swelled again after two weeks of oral administration (Figure 3E). MRI revealed a lot of fluid accumulation in the subacromial-subdeltoid region with necrotic synovial tissue floating (Figure 3A and B). In view of the large amount of fluid accumulation in the joint cavity, the joint cavity puncture was performed, and about 100 mL of yellow turbid liquid was extracted. The fungus culture showed that there was still Candida parapsilosis. Then the joint cavity was punctured for many times due to repeated swelling of the shoulder joint. Ultrasound examination showed joint cavity effusion, synovial hyperplasia, and some synovium looked like "floating weeds" (Figure 3C and D). In view of the recurring symptoms, arthroscopic surgery was performed again to clean the joint and a catheter was placed for irrigation and drainage (1 for irrigation and 1 for drainage). Under arthroscopy, there is no obvious rice body formation in the joint cavity, but a large amount of necrotic synovial tissue floating as seen in ultrasound (Figure 3F). A large amount of necrotic tissue flows out from the drainage tube and was pulled out due to blockage 10 days later. After operation, 400mg voriconazole was given intravenously, and 200mg bid was taken orally after three consecutive negative cultures. At present, the patient has received oral treatment for 8 weeks and change to the fluconazole (200 mg/bid) 4 weeks for the damage of liver function, without swelling again, and the subsequent culture is negative. The patient has been treated for 6 months and has not recurred.