Basal Cell Nevus Syndrome
This rare disease is inherited as an autosomal dominant trait with high penetrance and variable expressivity. The major features are multiple BCCs which appear at birth or in early childhood. Numerous small pits are found on the palms and soles. Epithelium-lined jaw cysts, which commonly cause symptoms may be initially discovered by the dentist. Ectopic calcification with lamellar calcification of falx cerebri and a variety of skeletal abnormalities, especially of the ribs, skull, and spine are common features. A characteristic facies is present in approximately 70% of patients. Physical findings include “coarse face”, relative macrocephaly, hypertelorism and frontal bossing.
There is great variation in the number and behavior of the nevoid BCCs. The median number is 8. Although many patients have no BCCs or just a few, more than 1000 BCCs can be present. The first tumor occurs at a mean age of 23. Locally destructive tumors are not seen before puberty. Aggressive behavior can occur after puberty, and all patients must be followed closely. Most of the highly invasive tumors involve embryonic cleft areas of the face. Development of multiple BCCs is enhanced by exposure to light and x-ray irradiation, but they also occur on unexposed surfaces.
Multiple bilateral jaw cysts are the presenting complaint in approximately 50% of patients; a dentist, R.J. Gorlin, discovered the syndrome. The cysts appear during the first decade of life and displace the child’s teeth, often in the premolar area. They cause pain, drainage, and jaw swelling. The occurrence of multiple skeletal anomalies is highly suggestive and may be the earliest clue to the diagnosis of nevoid BCC syndrome in children.