Scapulothoracic bursitis, a rare lesion of the thoracic wall, usually presents as a cystic mass growing at the scapulothoracic interface. Histopathologically, it is characterized by the presence of synovial cells lining the interior of the thickened fibrotic cystic wall and capillary proliferation. A 48-year-old male patient was admitted to our clinic with a complaint of swelling in the back. The magnetic resonance imaging of the lung and mediastinum showed a 43 mm × 130 mm axial lesion in the left infrascapular area between the external muscles and the serratus anterior muscle, hyperintense on T2 sequence, not suppressed on fat-suppressed sequences, with a peripheral minimally contrasted septated collection area. The patient underwent surgical total excision and was discharged on the second postoperative day with no morbidity. Histopathology of the tissue was reported as soft tissue compatible with an inflamed cyst wall with prominent fibroblastic proliferation. Scapulothoracic bursitis lesions can be treated with non-invasive or minimally invasive methods. However, when it becomes a giant lesion occupying space on the thoracic wall and has hemorrhagic content, surgical excision is the treatment of choice.