Multiple distant muscular metastases from non-small cell lung carcinoma evidenced by 18F-FDG PET/CT.

18F-FDG PET/CT is widely known to be able to detect unsuspected metastatic lesions such as multiple metastatic muscle involvements in various types of cancer. Moreover, 18F-FDG PET/CT has been demonstrated to show a metastatic muscle involvement before any definite morphologic changes.1 The adenocarcinoma of the lung is the most common primary tumor site when a muscular metastatic lesion is present and 18F-FDG PET/CT imaging is useful in detecting muscle involvements in lung cancer patients.2 Many physiological factors like tissue blood flow, pressure and metabolism have been cited possible reasons why skeletal muscle metastasis from lung cancer is a rare finding: in most cases only single metastases are reported, while multiple muscular metastases from lung carcinoma are even more exceptional and only two cases can be found in literature.3 Thigh, iliopsoas, and paraspinous muscles are the most frequent sites of reported clinical involvement. The metastatic muscular involvement is demonstrated to correlate with a poor survival, which is consistent with the fact that it generally occurs as a feature of systemic spread.1 The most frequent presentation of skeletal muscle metastasis from lung carcinoma is pain with or without swelling and diagnosis