Esophageal Cancer Presenting as a Case of Polymyositis

Abstract

Purpose: We report a case of polymyositis (PM) associated with esophageal cancer. This presentation is rare Methods: A 63 year old white gentleman presented to the our medical center with symptoms of progressive worsening in his ability to initiate a swallow, difficulty standing up from a sitting position without the use of the upper extremities and difficulty combing his hair. These symptoms were progressive. He reported mild weight loss. He had bilateral symmetrical muscle weakness. His laboratory tests were significant for an elevated creatine kinase and lactate dehydrogenase. Radiological studies assessing swallowing were consistent with transfer dysphagia. Electromyography (EMG) was consistent with a myopathy. Overlap syndromes, myotonic dystrophy, and myasthenia were ruled out. He was given the diagnosis of PM, and an upper endoscopy performed as a part of cancer workup revealed a 6 cm flat exophytic mass in the distal esophagus. Biopsies revealed an adenocarcinoma. It was staged at IIA. The patient was treated with a combination of chemoradiotherapy and surgery. The myopathy symptoms subsided totally as the patient recovered. Results: PM is classified as an idiopathic inflammatory myopathy. Its prevalence rate is estimated at approximately one per 100,000 in the general population. There is a female to male predominance of about 2:1. The peak incidence in adults occurs between the ages of 40 and 50, but individuals of any age may be affected. PM can either be a pure entity (sole presentation) or associated with an overlap syndrome or associated with cancer (paraneoplastic syndrome). Muscle weakness is the most common presenting feature. The onset is usually insidious, with gradual worsening over a period of several months. However, an acute onset has been described. The distribution of weakness is symmetric and proximal. Diagnosis is usually based on the clinical picture, abnormal muscle enzymes, abnormal EMG, the presence of myositis specific antibodies, and a muscle biopsy. PM is associated with an increased incidence of cancer although the precise links among the two entities remain incompletely understood. Cancer of the cervix, lung, ovaries, pancreas, bladder, and stomach account for approximately 70 percent of the cancers associated with inflammatory myopathies. Esophageal cancer is very rarely associated with PM. A possible delay in the diagnosis of esophageal cancer is due to the fact that PM causes weakness of the muscles in the upper esophagus and occasionally the dysphagia caused by the cancer can be attributed to the former. Conclusion: In conclusion, esophageal cancer should be considered in the differential diagnosis in patients presenting with PM as early diagnosis can translate into better survival.