[A case of congenital dermal sinus in the parietal region (author's transl)]

A congenital dermal sinus at the midline of the parietal region, which extends into the falx, is relatively rare. The following case is illustrative. A 3-year-old girl was noticed by her parents to have tumor at the midline of the parietal region without other disturbances and complaints. This girl had the normal mental and motor development, and was admitted to our clinic for cosmetic surgery. A round, elastic soft tumor, roughly 1x1x1 cm in diameter, was located at the midline of the parietal region. This tumor had a port wine cutaneous discoloration and an absence of normal hair growth in this area. Abnormal hair did not protrude from the sinus. This tumor had no dimple nor sinus opening. Skull XP showed a round lucent bone defect at the midline of the parietal region. This bone defect with sclerotic margin, was about 1 cm in diameter. Skull XP and tomography, with contrast medium injection into the tumor, showed that this tumor extended into the falx through bone defect. Angiography showed that there were no relations between the tumor and the superior sagittal sinus. PEG showed that there were no mass lesion nor dilatation of ventricles. Both spinal tap and EEG were normal. Operation for the congenital dermal sinus was performed on Nov. 4, 1977. This congenital dermal sinus extended into the falx and congenital cell rest tumor was not elicited.