Combined unilateral coronal and intraoral approach with zygomatic arch osteotomy for a dumbbell-shaped atypical lipomatous tumor of the temporal region extending into the infratemporal fossa.

Atypical lipomatous tumor (ALT) is rare in the head and neck, and dumbbell-shaped lesions beneath the zygomatic arch can complicate access. A 58-year-old man presented with an enlarging right temporal mass. Contrast-enhanced computed tomography and noncontrast magnetic resonance imaging showed a 125-mm lipomatous dumbbell-shaped tumor extending into the infratemporal fossa. Incisional biopsy suggested ALT. Marginal en bloc resection was performed using a unilateral coronal scalp incision and intraoral approach with zygomatic arch osteotomy and titanium plate fixation. Histology showed thick fibrous septa with atypical spindle cells; immunohistochemistry demonstrated positivity for CDK4 and weak positivity for MDM 2, consistent with ALT (FNCLCC histological grade 1) with no definite positive margin. At 4 years, no recurrence was seen, with no facial nerve palsy or masticatory dysfunction. Combined coronal-intraoral exposure with zygomatic arch osteotomy may facilitate marginal en bloc resection of temporal-infratemporal ALT.