CRANIOCEREBRAL EPIDERMOID AND DERMOID TUMORS - A REVIEW OF 32 CASES

We reviewed 22 epidermoid and 10 dermoid tumours of the skull and brai n from patients operated on consecutively at Henry Ford Hospital betwe en 1975 and 1991. There were 19 intradural (16 epidermoid, 3 dermoid) and 13 extradural (6 epidermoid, 7 dermoid) lesions. The average age a t presentation was 35 years for patients with epidermoids and 15 years for those with dermoids. Common clinical presentations for patients w ith intradural lesions included headache, visual deficits, and seizure s, whereas patients with extradural lesions harbored asymptomatic scal p masses. All patients with intradural lesions were investigated with computed tomography (CT) and cerebral angiography, and 8 patients unde rwent magnetic resonance imaging (MRI). Total resection was possible i n 12 (92%) of 13 extradural tumours, all with excellent outcomes. Eigh t (42%) of the intradural tumours were completely resected. Overall, w ith the intradural tumours we had good to excellent results in 17 pati ents (90%), poor results in 1 (5%), and 1 death (5%). Re-operation was needed in 5 intradural recurrences (26%) with deterioration in only o ne patient's neurologic status postoperatively. From a review of ours and others' data, we conclude that 1) these tumours have an insidious onset despite significant size and mass effect as demonstrated by imag ing studies; 2) CT, angiography, and particularly MRI help to define t he extent of subarachnoid tumour spread and involvement of neurovascul ar structures, thus permitting better surgical planning; 3) a signific ant number of intradural tumours are difficult to excise because of th eir adherence to neurovascular structures, and thus are related to hig her morbidity and mortality; and 4) because of extremely slow growth, complete tumour resection should not be the goal at the risk of injury to neurovascular structures.