Report of eight cases of occipital dermal sinus: An update, and MRI findings

Objective: We report our experience with 8 patients who were ultimately dia gnosed as having occipital dermal sinuses. Clinical presentation, imaging f indings and outcome are discussed, along with a review of the literature. S tudy Design: In eight patients with occipital dermal sinuses, we retrospect ively collected the following data: time to diagnosis, presenting signs, de rmal anomalies, location of bone defects, intraparenchymal extension, surgi cal techniques and clinical outcome. Conventional radiography was performed in all patients; computerized tomography (CT) scans and magnetic resonance imaging (MRI) in all but two. Results: Time to diagnosis ranged from 3 mon ths to 9 years. Presenting symptoms were: infection of a cutaneous mass (n = 4), occipital mass (n = 2), intracranial hypertension related to intra-ce rebral abscess (n = 2). In all patients, dermal sinus was located near the external protuberance of the occipital bone. in all patients but one, a cut aneous orifice was associated. Other cutaneous anomalies were: hairy nevus (n = 2) and subcutaneous cysts (n = 4). One patient had associated cranio-f acial malformations. Plain skull films revealed linear bony defects in all cases but one; CT scans revealed linear bony defects in all cases, osteitis and intra-parenchymal abscesses if present but they did not allow the deli neation of the sinus tract. MRI performed in six patients allowed a better appreciation of the malformation revealing intracranial abscess (n = 1), th e sinus tract (n = 2), inclusion cysts (n = 2), and associated venous anoma lies (n = 1). Surgery was performed in all patients: a complete removal of the dermal sinus was obtained in all patients but one; inclusion cysts were found in six patients. Total recovery without sequelae was obtained in all patients, except one who suffered from developmental delay and a polymalfo rmative syndrome. Conclusions: In newborns, a meticulous visual exploration of the midline skin along the craniospinal axis is necessary to detect con genital dermal abnormalities. Early surgery is required to prevent severe i ntracranial infection. MRI could help to determine the surgical approach by delineation of the sinus tract, its extension into deeper tissues and its association with cysts, abscesses or venous anomalies.