From head and neck lipoma to liposarcoma: a wide spectrum of differential diagnoses and their therapeutic implications

Purpose of review To overview the array of differential diagnoses among lipomatous tumours of the head and neck with special focus on their evaluation, three-dimensional assessment, and their available treatments. Recent findings The head and neck is an infrequent localization for lipomatous tumours, even though they represent the most common mesenchymal lesions. Lipoma, spindle cell/pleomorphic lipoma (SC/PL), atypical lipomatous tumour/well differentiated liposarcoma (ALT/WDLPS), de-differentiated liposarcoma (DDLPS), myxoid liposarcoma (MLPS), and pleomorphic liposarcoma (PLPS) are the most distinctive histotypes. Lipoma and SC/PL present alterations of chromosomes 12 and 13, ALT/WDLPS and DDLPS both show the Mouse Double Minute 2 amplification, whereas MLPS presents a CHOP gene fusion. Diagnosis of PLPS is purely morphological as there is no pathognomonic genetic alteration identified to date. Radiological assessment can be challenging for the presence of nonadipose components within the lesion. Surgery is the mainstay of treatment, even though achieving true radicality in terms of a large cuff of healthy tissue surrounding the tumour is not always realistic in the head and neck. Adjuvant radiation, eventually in combination with systemic chemotherapy, has been shown to improve overall survival in patients with positive margins, high-grade, deep, and more than 5 cm lesions. Further studies should be aimed at the evaluation of the role of hadron therapy, as well as targeted drugs against overexpressed proteins. Adequate differential diagnosis of the histotypes collected under the umbrella term of head and neck lipomatous tumours plays a fundamental role in treatment and follow-up of these lesions and requires specific expertise with referral to high-volume centres.