CT and MRI Findings of Head and Neck Masson’s Tumor: A Rare Case Report and Systematic Review of the Literature

Background: Masson’s tumor (MT) is a rare benign vascular disease. In literature, detailed description of its radiological findings is not available and functional imaging such as diffusion weighted (DW)-MRI has never been described. We aim to summarize the CT and MRI findings in our representative case and to conduct a systematic review of the literature. Case Presentation: We reported a 54-year-old ex-smoker male patient who presented with a nodular mass to the left cheek. He denied any previous trauma. CT examination performed on initial presentation revealed a well circumscribed solid oval mass with soft tissue density, a calcified focus and no significative contrast enhancement after contrast administration. MRI showed a well circumscribed solid oval mass, with intermediate T2 signal intensity with areas of high T2 signal intensity and the presence of peripheral high-flow serpentine vessels, low T1 signal intensity. The mass showed a non-enhancing area with enhancing vessels after intravenous contrast administration. We surveyed CT and MRI findings of head and neck MT of English and French language papers, published from 1981 to 2019, together with our representative case. We included articles with a description of CT and/or MRI findings of head and neck MT. Conclusion: We have experienced one case and have evaluated imaging findings through systematic review. Only 36 articles were eligible. CT and MRI findings were reported in 27 and 23 articles, respectively. To date, no diffusion weighted imaging (DWI)-MRI findings have been described. The most frequent findings in CT were a well-defined mass with high or soft tissue density. The most frequent MRI findings were a non-homogeneous signal intensity in T1 and T2 weighted sequences, with foci of hyperintensity, multiple septations or flow voids. After contrast administration, the enhancement could be homogeneous, non-homo-geneous, nodular or peripheral. In our case, we found a non-homogeneous hyperintensity in DWI-MRI with an area of restricted diffusion and low apparent diffusion coefficient (ADC) was observed (0.963 × 10 −3 mm 2 /s +\-0.12 SD). The imaging characteristics cannot provide a pre-operative identikit of MT and surgical removal is necessary to accurately differentiate it from malignant angiosarcoma but radiological evaluation is useful in surgical planning.