Temporalis Muscle Abscess With Secondary Extension Into the Orbit.

Abstract

A 33-year-old woman presented with intermittent left-sided periorbital swelling and facial pain. She had a history of dental procedures to the left upper and lower molars a few months prior. MRI revealed an abscess within the left temporalis muscle measuring 1.5 × 1.9 × 3.9 cm with associated mild inflammation involving the left lateral orbit (Fig. 1). An ultrasound-guided aspiration of the abscess revealed Streptococcus, Prevotella, and Propionibacterium species. After treatment with intravenous piperacillin/tazobactam for 4 days, her eye exam continued to worsen with a new abduction deficit on the left side and 1 mm of proptosis. Repeat MRI demonstrated a distinct, 1.3 cm subperiosteal abscess along the lateral orbit (Fig. 2). The patient was taken to the operating room for orbitotomy and drainage of abscess with placement of a Penrose drain. A culture of the contents showed no growth as she had received several days of intravenous antibiotics. The patient subsequently had an uncomplicated postoperative course and was discharged 1 week later.FIG. 1.: Initial axial MRI showing a large abscess (arrow) within the left temporalis muscle and associated inflammatory changes within the preseptal and postseptal tissues.FIG. 2.: Repeat axial MRI demonstrating a subperiosteal abscess of the left lateral orbit (arrow) adjacent to the temporalis abscess causing unilateral proptosis.This is a case of a temporalis muscle abscess with likely secondary extension into the orbit. To the authors’ knowledge, this presentation has never been described previously. The authors suspect that the route of infectious extension into the orbit was via the zygomaticotemporal foramen which is located at the anterolateral wall and transmits the zygomaticotemporal neurovascular bundle.