Myxolipoma in the buccal region: A case report and review of literature

Abstract

Lipomas are benign mesenchymal tumors with a relatively high incidence rate. However, myxolipomas, a histological variant characterized by mature adipose tissue and abundant myxoid substances, are rare, especially in the oral cavity. This case report focuses on a 90-year-old-female patient, the oldest reported with oral myxolipoma, who presented with the chief complaint of a painless mass in her right buccal region that had persisted for several years. The mass (approximately 25 mm in diameter) was palpable, soft, elastic, and covered with normal mucosa. In general, the Hounsfield unit (HU) of lipomas is approximately –100 units on computed tomography, and lipomas show high signal intensity on both T1- and T2-weighted magnetic resonance imaging. In contrast, in this case, the HU was approximately 50 units, which is slightly lower than that of the common muscle, similar to a previous report on myxomas. Unlike common lipomas, the present case exhibited low and high signal intensities on T1- and T2-weighted images, respectively. The tumor was surgically excised under local anesthesia and histopathological examination revealed a well-defined lobulated mass surrounded by a thin fibrous capsule. The tumor cells exhibited a solid proliferation of mature adipocytes, which were replaced by abundant myxoid substances. Based on these findings, the patient was diagnosed with a myxolipoma. Myxolipoma should be considered as a differential diagnosis when myxomas are suspected on preoperative imaging studies. The postoperative follow-up was uneventful, and no evidence of recurrence was observed 2 years postoperatively.