MR Findings of Primary Scalp Mass

PURPOSE: To evaluate the diagnostic value of MRI, we compared MR images of primary scalp mass with pathological findings. MATERIAL & METHODS: Eight cases in seven patients who had presented primary scalp mass during the previous three years were evaluated by MRI and confirmed with surgical excision and pathologic evaluation. 0.38T(Resonex 4000, USA) MRI was used and all MR images were analysed retrospectively. RESULTS: Eight pathologically confirmed cases consisted of three cases of epidermal cysts, one of steatocystoma simplex, three of neurofibromatosis and one of lymphangioma. All epidermal cysts were located in the occipital area and showed ahigher signal intensity than CSF in T1WI, and proton density and variable signal intensity in T2WI. The Steatocystoma showed a signal iniensity similar to fat in T1WI and proton density and a lower signal intensity than fat in T2WI. Neurofibromatosis accounted for three cases in two neurofibromatosis patients ; one was locatedin the right parieto-occipital area and accompanied by hematoma and skull defect ; two cases were located in the occipital and posterior cervical area of the same patient. The masses showed a higher signal intensity than musclein T1WI and hyper or iso intensity in T2WI with well enhancement. The lymphangioma showed a signal intensity similar to CSF in all pulse sequences and contained a fat component. CONCLUSION: MRI is a useful modality for evaluating primary scalp mass.