Spindle cell lipoma of the head and neck: CT and MR imaging findings.

INTRODUCTION: Spindle cell lipoma (SCL) is an uncommon benign lipomatous tumor, most commonly occurring in the posterior neck and shoulder. The purpose of this study was to investigate the CT and MR imaging features of SCL in the head and neck.

METHODS: CT (n = 5) and MR (n = 3) images of seven patients (five men and two women; mean age, 54 years) with surgically proven SCL in the head and neck were retrospectively reviewed. The location and morphologic characteristics of SCL were documented as well.

RESULTS: Six lesions were well-defined and located in the subcutaneous fat of the posterior neck (n = 4), anterior neck (n = 1), and buccal space (n = 1). One lesion was ill-defined and located deeply in the supraclavicular fossa, infiltrating the adjacent shoulder muscles. Intratumoral fat was identified in five lesions in various amounts. Compared with the adjacent subcutaneous fat, intratumoral fat was slightly hyperattenuated on CT scans and slightly hypointense on T1-weighted MR images. In five of six lesions in which postcontrast CT and/or MR images were obtained, significant enhancement was seen in the nonadipose component of the lesion.

CONCLUSION: Various components of the adipose and nonadipose tissues may cause difficulty differentiating between SCL and other adipocytic tumors including liposarcoma radiologically. Although nonspecific, the radiologist should know the various imaging features of SCL, because the tumor can be cured by simple excision.