Pleomorphic Lipoma of the Tongue as Potential Mimic of Liposarcoma
A 44-year-old woman presented with a slow-growing, painless nodule of the tongue with difficulty in deglutition. Clinical examination revealed a soft, sub-mucosal nodule, measuring approximately 3 cm in maximum diameter, covered by normal mucosa. A surgical excision was performed. Grossly, the mass was poor circumscribed and lipomatous in appearance with mucoid areas. Histological examination showed mature adipocytes, diffusely infiltrating striated muscle fibres, [] and abundant mucoid stroma []. In this myxoid background were present bland-appearing spindle cells and multinucleated giant cells with radially arranged nuclei in a “floret-like” pattern []. Some thick rope-like collagen bundles were also present. The spindle and giant cells were strongly positive for CD34 [] and negative for S100. A fluorescence in situ hybridization (FISH) was performed on formalin-fixed, paraffin-embedded tissue sections using MDM2 (12q15) dual-colour probe (Vysis, Downers Grove, IL, USA). No amplification of the MDM2 gene was disclosed. A final diagnosis of pleomorphic lipoma of the tongue was made. The post-operative course was uneventful; after 1 year, the patient was free of disease although the tumour was present at the margins of the excised specimen and is currently on follow-up.