Antral adenocarcinoma with skeletal muscle metastasis mimicking polymyositis: A case report

Abstract

Intramuscular metastasis from gastric carcinoma is extremely rare with the exact incidence remains unknown. It may be difficult to distinguish intramuscular metastasis clinically from inflammatory myositis. We describe here the radiological and diagnostic features of an elderly lady presented with antral adenocarcinoma, complicated further by extensive skeletal muscle metastasis that was initially diagnosed as polymyositis. Good clinical history, thorough physical examination and appropriate imaging evaluation are the mainstay in the diagnosis as it is a great challenge in differentiating between intramuscular metastasis and polymyositis through imaging. It is vital to include intramuscular metastasis as a major differential diagnosis, in view of the differences in treatment, prognosis and long-term follow up including a histopathological examination to further ascertain diagnosis.