Oncocytic lipoadenoma of submandibular gland: a case report

Lipomatous tumours of salivary glands are very uncommonly diagnosed and reported tumours. Majority of these tumours present as painless masses which grow slowly over many years. On the histological grounds, they can be subclassified into "monophasic" (lipoma component only) and "biphasic" (lipoma component+epithelial component) tumours. A handful of biphasic tumours contain oncocytic component and they have been omitted from the WHO classification of salivary gland tumours so far and this has remained a matter of persistent confusion and controversy over many years. Other rare variants of monophasic tumours include fibrolipoma, sialolipoma, angiolipoma, sialadenosis and very rarely a liposarcoma can also occur in salivary glands. Pre-operative imaging can help in picking up the fatty component of the tumours and guide in accurate classification. FNAC may not be accurate in diagnosis of these tumours. We report a case of 45-year-old gentleman presenting with submandibular gland swelling for which submandibular gland excision was done. A final diagnosis of oncocytic lipoadenoma was made. We present this rare entity to add to the few cases reported to date and hence, to increase recognisation and understanding of these rare tumours, which may help in establishing a reproducible subclassification. We have discussed the pathological aspects with review of literature of this very rare entity.