CT and MR imaging findings of solitary nevus lipomatosus cutaneous superficialis: radiological-pathological correlation

Objective This study assessed the CT and MRI findings of solitary nevus lipomatosus cutaneous superficialis (NLCS). Materials and methods Eleven patients with histopathologically and clinically confirmed solitary NLCS who underwent CT and/or MRI were enrolled. Radiological and histopathological findings of elevated lesions located above the level of the surrounding normal skin surface and coexisting subcutaneous lipoma-like lesions were assessed retrospectively. Results Elevated skin lesions were observed in all 11 patients; these lesions were pedunculated in 4 patients (36%) and broad-based in 7 (64%). The CT attenuation of elevated lesions was fat attenuation in 2 out of 7 patients (29%), slightly increased fat attenuation in 4 out of 7 (57%), and combined fat and soft-tissue attenuation in 1 out of 7 (14%). The MR signal intensity of elevated lesions on T1-weighted images was fat signal intensity in 2 out of 6 patients (33%), slightly decreased fat signal intensity in 3 out of 6 (50%), and combined fat signal intensity and hypointensity in 1 out of 6 (17%). Subcutaneous lipoma-like lesions with fat attenuation and/or fat signal intensity were observed in 6 out of 11 patients (55%). Histopathologically, various amounts of fatty tissue and collagenous fiber were observed within the elevated lesions in all 11 patients. Conclusion The CT and MRI features of solitary NLCS were the broad-based or pedunculated elevated lesions, including fatty components. Additionally, subcutaneous lipoma-like lesions were frequently observed.