脂肪瘤是由一層薄薄的纖維外膜所包覆，由脂肪細胞所組成的良性間質細胞腫瘤。它們幾乎是身體上最常見的軟組織腫瘤，然而，它們卻很少出現在口腔內。當發生在口腔時它們通常是生長緩慢、無痛及沒有症狀的微黃色皮下腫塊，它們可能會生長到很大的尺寸而造成咀嚼及說話困難。適當的手術摘除以避免復發是最好的治療選擇。這裡要提出的病例是一位65歲的女性病患，她主要是在口腔前底部左側有一約10年之久生長緩慢的無痛腫塊，治療方式是以口內局部麻醉的方式將其摘除。

Lipomas are benign mesenchymal neoplasms composed of mature adipocytes, usually surrounded by a thin fibrous capsule. They are among the most common soft tissue tumors of the human body. However,they are uncommon in the oral cavity. They present as a slow growing, painless and asymptomatic yellowish submucosal mass in the oral cavity. They have been known to grow to large sizes causing mastication and speech difficulties. Treatment of lipomas consists of simple surgical removal with no recurrence being expected.This paper presents a case of a 65-year-old female who presented with a slow growing floor-of-mouth swelling causing mastication difficulties that was treated by intraoral local excision.