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

This study assessed the CT and MRI findings of solitary nevus lipomatosus cutaneous superficialis (NLCS). 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. 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. 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.