Diagnosis: Malignant pleural mesothelioma
The chest radiograph revealed pleural-based masses extending along the convexity of the right chest wall. (Note the diminished volume of the right lung in FIGURE 1.) A coronal enhanced computed tomography (CT) scan (FIGURE 2) showed a large heterogeneous mass extending through the chest wall into the right axillary soft tissue and encasing the right brachial plexus (yellow arrows). Transdiaphragmatic extension was evident as an irregular mass at the hepatic dome (red arrow). The constellation of findings prompted the radiologist to suspect pleural malignancy.
An aggressive cancer
MPM is a highly aggressive neoplasm of the pleura with rising incidence around the globe.1,2 The annual incidence of mesothelioma in the United States is approximately 3000 cases per year, with the majority linked to asbestos exposure. The latency period is long, typically ranging from 35 to 40 years.1 Our patient, however, did not have a history of asbestos exposure. She was a housewife who had no exposure to building construction or demolition.
Nonspecific complaints. Clinical findings of MPM are frequently nonspecific and may masquerade as innocuous shoulder pain, as illustrated in this case. Patients may also present with dyspnea, nonpleuritic chest pain, and incidental pleural effusions. On examination, unilateral dullness on percussion at the lung base, palpable chest wall masses, and scoliosis toward the sides of the lesion may be present.3
Differential Dx of shoulder pain includes rotator cuff disorders, tears
The differential diagnosis of shoulder pain includes rotator cuff disorders, acromioclavicular osteoarthritis, and cervical radiculopathy from degenerative spondylosis.
Rotator cuff tendinopathy and tears usually present with pain on overhead activity, positional test muscle weakness, and evidence of impingement. Acromioclavicular osteoarthritis usually causes acromioclavicular joint tenderness, which can be relieved with diagnostic intra-articular anesthetic injections. Pain from cervical spondylosis is usually accompanied by numbness and weakness in the arms and hands and muscle spasms in the neck. Also, the symptoms are usually aggravated by downward compression of the head (Spurling’s test).4,5