A 62-year-old man with a history of hypertension, coronary artery disease, and hemodialysis-dependent end-stage renal disease presents to the emergency department (ED) with the complaint of right shoulder pain that has been worsening over the last 2 months, with associated progressive swelling over the acromioclavicular (AC) joint (see Figure 1). The patient denies any recent heavy lifting or trauma. He also denies fever, erythema, or warmth of the right shoulder. There has been no drainage from the mass. The patient’s medications include clonidine, carvedilol, sevelamer, amlodipine/benazepril, cinacalcet, and lanthanum carbonate. His surgical history is notable for a left brachiocephalic fistula. The patient has no allergies to medications and denies any tobacco, alcohol, and illicit drug use. The family history is noncontributory.
The physical examination shows a well-appearing, middle-aged man in no acute distress. His temperature is 98.9°F (37.2°C), blood pressure is 130/88 mm Hg, heart rate is 62 bpm, and respiratory rate is 18 breaths/min. On examination of the right shoulder, there is a large, tense, fluctuant mass over the right AC joint, which is superficial and measures 10 × 7 × 4 cm. There is significant tenderness to palpation in this area. The skin is intact and there is no erythema or warmth of the shoulder area. Internal and external rotation of the shoulder is significantly impaired resulting from pain, and there is weakness with rotator cuff testing. The patient is unable to lift his arm past 30° of forward flexion or abduction. The distal motor, sensation, and reflex examinations are otherwise unremarkable. The extremity pulses are normal. Besides a left arm brachiocephalic fistula with a positive bruit and palpable thrill, the remainder of the physical examination is unremarkable.
The patient is given oral analgesics for pain control and a radiograph of the right shoulder is subsequently obtained. The right shoulder radiograph does not demonstrate any fracture (see Figure 2), but it does show evidence of a high-riding humerus and advanced deformity of the humeral head. There is also a large soft-tissue mass noted to protrude above the AC joint. The patient had laboratory examinations performed at an outside clinic that morning, which demonstrated a normal C-reactive protein, erythrocyte sedimentation rate, and complete blood count.
After reviewing the above films, the orthopedist on call is consulted to assist with patient management. The orthopedic surgeon recommends obtaining a magnetic resonance imaging (MRI) scan of the right shoulder (see Figure 3) to provide further information on the shoulder mass.
Question: What is the likely diagnosis? Hint: Consider the history of a slowly enlarging mass for 2 months without associated fever, warmth, or erythema in a nontoxic patient.
Carpal Tunnel Surgery (18/12/2010)
