A 51-year-old patient was admitted to the outpatient department with swelling to the right shoulder and surrounding area, a skin wound, restriction in shoulder movement, and pain. The patient received rotator cuff repair surgery four years prior at an external clinic. Following the initial repair, she was operated on a total of 13 more times to address the infection, based on persistent pain and wound discharge, finally resulting in a final bone resection. The patient reported that the erythema, swelling, and tenderness in her right shoulder reappeared one month before admission to this current clinic. Her medical history revealed that she was under follow-up by the rheumatology department at another hospital for Behcet's disease and that she did not receive anti- tumor necrosis factor (anti-TNF) drug therapy at the time of admission; however, she received oral steroids for a significant period of time. The patient was also being treated for hypertension. 
A physical examination revealed a yellow-brown swollen nodular lesion with a necrotic surface and lobular contour, located on the anterior part of the shoulder joint, approximately 7.5 cm in size (Figure 1). The circumference of the shoulder was oedematous, and shoulder movements were painful and limited in all directions. There were no palpable lymph nodes around the shoulder. During radiographic examination, contrast-enhanced magnetic resonance imaging (MRI) was performed, following the inspection of previous direct radiographs provided by the patient herself. Contrast-enhanced MRI assessment revealed a complete resorption appearance in the right humeral head, extending to proximal diaphysis; soft tissue appearances in the resorption zone, which were thought to belong to severe hypertrophic synovial tissues; full-thickness defect in the subcutaneous adipose tissue at shoulder level and in the deltoid muscle, extending to humeral head level; and condensed liquid collection and continuity of this collection within the proximal resorbed humerus zone. The supraspinatus, infraspinatus, and subscapularis muscles all presented with a highly fatty atrophy appearance. However, MRI was inadequate to clearly identify whether the fluids were infected (Figure 2). 
In her routine blood tests, leukocyte was 8.2 Tu/L, erythrocyte sedimentation rate was 77 mm/h, and C-reactive protein was 19.14 mg/L. A culture sample was taken from the wound discharge on the patient's shoulder; however, it showed no reproduction during culture sample monitoring. After clinical evaluation, septic arthritis was considered. To make a microbiological diagnosis and to obtain pathology and culture samples for differential diagnosis of other possible pathologies, such as neoplasms, an excision of the sinus tract, extending into the joint, and skin lesion and joint debridement were planned. A written informed consent was obtained from the patient. 
The patient was operated on under general anesthesia. To avoid affecting the culture samples taken during surgery, intravenous cefazolin sodium (1 g) (Cezol; Deva Holding AS, Istanbul, Turkey) was administered for surgical prophylaxis, after the samples were taken. During surgery, the patient was in a beach chair position with an arm board to support her right elbow and forearm. Prior to surgery, a Z-plasty incision was planned to allow for closure of the skin after the mass was removed. Following the incision around the mass, dissection was carried out and advanced through the deltopectoral space. Preserving the axillary vessel-nerve package, the mass, including the joint capsule, was excised extensively along with the anterior fibers of the deltoid muscle. Subsequently, the shoulder joint was explored. Dead bone residues and infected synovial tissues were debrided, until bleeding was observed. At this stage, culture samples were taken for microbiological examination, followed by irrigation of the surgical field with approximately six liters of saline solution. A suction drain was inserted after bleeding was under control, and the wound was closed. Following surgery, the patient's shoulder was dressed using a Velpeau bandage. Physical therapy for the patient's elbow and wrist commenced on the first postoperative day. The suction drain was removed on the third postoperative day, and the patient was discharged. The remaining bone stock after surgery was evaluated on postoperative Day 15 by direct radiography (Figure 3). Macroscopic pathological examination revealed a 14.5x5.8x3.5-cm mass with papillary infoldings. On the cut surface, irregularly delineated white confluent foci were visible (Figure 4). Microscopically, granulomas with Langhans giant cells and caseous necrosis could be seen. Some granulomas were cuffed by lymphocytes (Figures 5 and 6). Acid-fast bacillus (AFB) stain showed TB bacilli in the necrotic areas and histiocytes (Figure 7); however, there was no reproduction in the joint fluid culture. The TB treatment was initiated by consulting with the Department of Infectious Diseases and Clinical Microbiology. At six months after surgery, TB treatment using a combination of drugs was ongoing, while the patient no longer experienced symptoms and pain related to the infection. Direct radiographic evaluation of the shoulder joint was made (Figure 8), and joint reconstruction was planned for the end of the medication treatment.