Gout is a common metabolic disorder characterized by recurrent episodes of arthritis associated with the presence of monosodium urate monohydrate crystals in synovial fluid leukocytes or periarticular soft tissues1. Tophaceous gout, representing the chronic phase of the disease process, usually occurs at least ten years before these lesions become visible radiographically or on physical examination2,3. Although gout frequently affects the feet, hands, wrists, elbows, and knees, involvement of the shoulder joint by gouty tophi is unusual4, and tophaceous gout of the rotator cuff is rare5.
The magnetic resonance imaging characteristics of tophaceous gout of the rotator cuff have not been previously described in the literature, to our knowledge. We report the case of a man with tophaceous gout of the rotator cuff who had plain radiography and magnetic resonance imaging as well as intraoperative and histopathologic correlation. The patient was informed that data concerning the case would be submitted for publication and consented.
A twenty-six-year-old man presented with a one-month history of intermittent pain and a limited range of motion of the right shoulder following a stretching injury at work when he tried to grasp the handrail of a ladder before falling off of it. An anti-inflammatory agent (tiaprofenic acid) was given on the third day after the injury, and this treatment was discontinued two weeks later because pain relief had been achieved. However, the pain returned soon thereafter. The patient stated that he had no systemic symptoms, medical history of hyperuricemia, or prior episodes of acute gouty arthritis.
Except for the problems with the right, involved shoulder, the findings of the general clinical examination were unremarkable. Physical examination of the right shoulder revealed substantially decreased active ranges of motion in forward flexion (30°), extension (10°), and abduction (30°) in comparison with the ranges on the unaffected side (180° of forward flexion, 45° of extension, and 150° of abduction). The passive ranges of motion of the right shoulder were also decreased in forward flexion (75°), extension (30°), and abduction (90°). The patient had a painful arc on resisted abduction between 70° and 120°, suggestive of rotator cuff tendinitis. Internal rotation (90°) and external rotation (90°) of the right shoulder were normal.
A plain radiograph of the right shoulder demonstrated a faint amorphous opacity above the humeral head (Fig. 1). Magnetic resonance imaging was performed with a 1.5-T magnetic resonance imaging unit (MAGNETOM Sonata; Siemens Medical Solutions, Erlangen, Germany) with use of a surface coil conforming to the curved shoulder girdle. Spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted images were obtained in the oblique coronal plane parallel to the supraspinatus tendon. The swollen supraspinatus tendon revealed intrasubstance areas of high signal intensity on T2-weighted and T2*-weighted images with an amorphous deposit of low signal intensity on the articular side on all magnetic resonance imaging sequences, which was consistent with the suspicion of calcific tendinosis (Figs. 2-A, 2-B, and 2-C). Abnormal effusion of high signal intensity was present in the subdeltoid bursa on T2-weighted and T2*-weighted images (Figs. 2-B and 2-C).
With the patient under general anesthesia, an open subacromial decompression (acromioplasty) was performed for removal of the abnormal deposit by dissection and débridement. The intraoperative findings revealed chalky, granular deposits consistent with gouty tophi on the articular side of the supraspinatus tendon when it was incised longitudinally (Fig. 3). Subsequent histopathologic examination of the tissue specimen demonstrated amorphous tophaceous deposits surrounded by granulomatous infiltrates consisting of multinucleated giant cells and histiocytes (Fig. 4). These intraoperative and histopathologic results confirmed the diagnosis of tophaceous gout of the rotator cuff.
There were no postoperative complications. The serum level of uric acid rose to a high of 11.7 mg/dL (695.9 µmol/L) (normal, <8.3 mg/dL [<493.7 µmol/L]) after the surgery. The patient was subsequently treated with colchicine and allopurinol. At the time of the one-year follow-up after treatment, the patient had a complete pain-free range of motion of the involved shoulder.