Temporal dermoid cyst with a partial dermal sinus tract

Background: Cranial dermal sinuses are rare and occur most frequently in th e posterior fossa and along the midline. Likewise, supratentorial dermoid c ysts are very uncommon. Method: We report a unique case of an adult female patient with both a supratentorial dermoid cyst and an incomplete dermal si nus tract. Results: The patient is a 31-year-old female, who presented with a new onset complex partial seizure. Neuroimaging and surgery revealed a r ight superior temporal dermoid cyst with an associated dermal sinus tract. Furthermore, the dermal sinus tract was incomplete and had no cutaneous man ifestations. Conclusion: We present a rare patient with an off midline supr atentorial dermoid cyst associated with a uniquely incomplete cranial derma l sinus tract. The dermal sinus tract involved the bone, dura and intradura l compartment, without involving the overlying skin. This represents a nove l variant in the spectrum of cranial dermal sinus abnormalities.