A 29-month-old boy presented to the emergency department with a 48-hour history of left palpebral swelling without inflammatory signs or other associated symptoms. No precipitating factors were identified. The parents reported three previous similar episodes in the last 1.5 years with spontaneous resolution within 48-72 hours. The other episodes were associated with serous drainage. On examination (Figure 1) there was a left palpebral soft swelling with extension to the frontal region. In the middle of the tumefaction there was a one-millimeter orifice, without spontaneous or by expression drainage. A soft tissues ultrasound was performed at the Emergency Department, that revealed a fistulous path from clinically evident dermal lesion with apparently intracranial extension, without signs of local complications. A magnetic resonance imaging (MRI) corroborated the ultrasound findings (Figure 2). In the present case, the patient was discharged with a programed neurosurgery appointment. The boy has maintained regular follow-up in pediatric and neurosurgery consultations, waiting for spontaneous resolution, once there were no major complications in the two-year follow-up period.
Figure 1. Lateral view from the head swelling.
Figure 2. MRI image from the lesion.
What is the diagnosis?