Well-Circumscribed Intramuscular Lipoma of Superior Rectus Muscle

Abstract

Extraocular muscle lipoma is a rare benign mesenchymal tumor of the orbit. We report a case of a 37-year-old woman who presented with chronic progressive proptosis and inferior globe displacement of left eye. External eye examination revealed a yellowish mass at the superior bulbar conjunctiva. Magnetic resonance imaging showed a well-circumscribed mass confined in the superior rectus muscle belly and tendon with a fat signal. Debulking surgery was performed using the transconjunctival and vertical lid split approach. A pathological study demonstrated matured adipose tissue cells encapsulated by a thin layer of fibrous tissue, in addition to the chronic non-specific inflammation of the tenon capsule tissue sample. Histopathological findings of the mass were consistent with a well-circumscribed intramuscular lipoma. The symptoms of the patient were significantly improved 3 months after surgical and short-course systemic steroid treatments. However, long-term surveillance is needed.

Keywords:

• intramuscular lipoma
• soft tissue tumor
• orbital tumor
• extraocular muscle
• well-circumscribed lipoma

Ethical and Consent Statements

Since the data were anonymous and no threat to patient’s rights, the Ethics Committee of Mettapracharak Hospital exempts the need for ethical approval. Written informed consent was provided by the patients to have the case details and any accompanying images published. The patient agreed to the publication of the case and images.

Disclosure

The authors report no conflicts of interest in this work.