Characteristic MRI Findings of Spinal Metastases from Various Primary Cancers: Retrospective Study of Pathologically-Confirmed Cases

ABSTRACT

PURPOSE: The purpose of this study was to find and categorize the various magnetic resonance imaging (MRI) findings of spinal metastases that correlate with the type of primary cancer. MATERIALS AND METHODS: We retrospectively reviewed gadolinium-enhanced magnetic resonance images of 30 patients with 169 spinal metastatic lesions from lung cancer (n = 56), breast cancer (n = 29), colorectal cancer (n = 20), hepatocellular carcinoma (HCC) (n = 17), and stomach cancer (n = 47). The size, location, extent of invasion, signal intensity, margin, enhancement pattern, and osteoblastic or osteolytic characteristics of each metastatic tumor were analyzed. RESULTS: The metastatic lesions from HCC were larger than those from the other primary tumors (P < 0.05) except for colorectal cancer (P = 0.268). Well-defined metastatic tumor margins were more frequently seen in lung cancer and breast cancer (P < 0.01). All but HCC showed a tendency to invade the vertebral body rather than the posterior elements (P < 0.02). Colorectal cancer and HCC showed a tendency toward extraosseous invasion without statistical significance. HCC showed a characteristic enhancement pattern of 'worms-in-a-bag'. Rim enhancement with a sclerotic center was only seen in spinal metastases from stomach cancer. CONCLUSION: Despite many overlapping imaging features, spinal metastases of various primary tumors display some characteristic MRI findings that can help identify the primary cancer.