脂肪瘤及其相關的次分類是在顎顏面區域不常見的良性軟組織腫瘤；典型的脂肪瘤可以在核磁共振的T1序列影像上被辨識及診斷。本報告提出一位46歲男性，其主訴為左臉有一無痛緩慢增大的腫塊，經核磁共振影像檢查發現在T2序列影像上可辨識到一影像強度增強，外形完整但有非均質內含物的皮下腫瘤，經病理檢查確診為非典型黏液狀脂肪瘤。我們認為有些脂肪瘤含有黏液狀內含物或其他成分時，在T1序列影像上無法典型的被辨識出來，這類的病灶仍需要其他輔助性的檢查才能獲得更充足的資訊來幫助臨床醫師做術前臆斷及治療計畫的訂定。

Lipomas, and associated subtypes, are common benign, soft tissue tumors that occur infrequently in the oral and maxillofacial region. Typically, lipomas can be diagnosed and characterized by T1-weighted imaging (T1WI) of magnetic resonance imaging (MRI). In the current case, a 46-year-old man presented with a painless, slow growing mass on the left middle face. An MRI revealed a well-defined subcutaneous mass of heterogeneous content that was markedly enhanced on T2-weighted imaging (T2WI). The diagnosis of atypical myxoid lipoma was confirmed by pathological examination. Based on our observations, we propose that some lipomas containing lipomatous tissues with myxoid zones and other components, and that do not exhibit a typical enhancement pattern by T1WI, require further investigation to aid in understanding the variant features apparent on images of these lesions.