An intramuscular lipoma is a deep-seated heterotopic benign mesenchymal tumor that originates in a skeletal muscle and infiltrates the adjacent muscle. It tends to recur after excision. This tumor is also referred to as “infiltrating lipoma" and differential diagnosis from well-differentiated liposarcoma is necessary.
Intramuscular lipoma is very rare in the oral and maxillofacial region. We describe a case of intramuscular lipoma occurring in the musculus pterygoideus medialis or lateralis that spread to the infratemporal fossa in association with mental nerve neuropathy in a 59-year-old man. With the patient under general anesthesia, we excised the tumor, including the circumferential tissue. At the 2.5-year postoperative evaluation, numbness had improved, with no evidence of recurrence.
