Photo Rounds

Forehead cyst

A 42-year-old man was referred from the Emergency Department to an outpatient procedure clinic for removal of a cyst on his right forehead. The patient said that the lesion did not bother him, but over the previous few months it had been growing, and more recently, had become red. He indicated that prior to the emergence of the cyst, he’d been in a car accident and hit his head. At the time, he’d not required medical attention.

What is your diagnosis?



Forehead cyst

Upon palpation, the physician noted a strong pulse consistent with a traumatic arteriovenous fistula (in this case involving the superficial temporal artery). This finding, combined with the cyst’s appearance and the patient’s history, led the physician conclude that this was an epidermoid (sebaceous) cyst. (Prior to palpation, the visual differential diagnosis included dermoid cyst, lipoma, trichilemmal or epidermoid cyst, and foreign body granuloma.)

Cystic nodules on the forehead and midline deserve close scrutiny. This author has seen 3 similar cases in 10 years of daily dermatology consultative practice that have involved the superficial temporal artery and a history of head trauma. Each case had been stable for many months before presentation and had been incorrectly identified as a more common benign cyst.

In this particular case, the planned procedure in the outpatient setting was cancelled and the patient was referred to Vascular Surgery, where surgeons were planning to perform a ligation of the superficial temporal artery.

Photos and text for Photo Rounds Friday courtesy of Jonathan Karnes, MD (copyright retained). Dr. Karnes is the medical director of MDFMR Dermatology Services, Augusta, ME.

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