Venous hemangioma of the temporalis muscle

A 14-year-old girl presented with a diffuse venous hemangioma of the right temporalis muscle. The muscle had become swollen, thinning the underlying zygomatic and temporal bones. Magnetic resonance (MR) imaging demonstrated a diffuse isointense area containing high intensity foci on the T1-weighted images, and a serpiginous high intensity pattern on the T2-weighted images. A biopsy specimen revealed irregularly dilated veins in the fibrous stroma of the muscle. Diffuse abnormal signals on MR images may be a pathognomonic feature of intramuscular venous hemangiomas.