Nevoid BCC syndrome (Gorlin's syndrome).

This rare disease is inherited as an autosomal dominant trait with high penetrance and variable expressivity. The gene is located on chromosome 9q22.3-q31. It has the following major features: multiple BCCs appear at birth or in early childhood; numerous small pits on the palms and soles (50% to 65%); epithelium-lined jaw cysts, which commonly cause symptoms (65% to 90%); ectopic calcification with lamellar calcification of falx cerebri (80%); and a variety of skeletal abnormalities, especially of the ribs, skull, and spine (70% to 75%). A characteristic facies is present in approximately 70% of patients . Numerous associated anomalies may be present. There is great variation in the number and behavior of the nevoid BCC. Although many patients have no BCCs or just a few, more than 250 BCCs can be present. 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; the syndrome was discovered by a dentist, R.J. Gorlin. 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. Complete or partial bridging of the sella turcica is present in 75% of patients. Splayed and bifurcated ribs occur in 40% of patients.
The initial evaluation of patients suspected of having BCC syndrome should include the following: (1) detailed family history; (2) dental consultations; and (3) x-rays of jaws, skull, chest, spinal column, and hands.

NEVOID BASAL CELL CARCINOMA SYNDROME

SKIN
Multiple nevoid basal cell carcinomas

Pits--palms and soles (50% to 65%)

Milia, cysts (epithelial and sebaceous)


FACE AND MOUTH
Multiple jaw cysts (65% to 90%)

Presenting complaint in 50%

Characteristic facies (70%)

Mandibular prognathism

Broadening of the nasal root (25%)

Frontal/temporoparietal bossing

Ocular hypertelorism


CENTRAL NERVOUS SYSTEM
Lamellar calcification of falx cerebri (80%)

Bridging of the sella turcica (75%)

Mental retardation

Electroencephalographic abnormalities


SKELETAL SYSTEM ANOMALIES (70% TO 75%)
Rib anomalies (55%): bifurcation and splaying (40%), synostotic, or partial agenesis or rudimentary cervical ribs

Vertebrae (65%): kyphoscoliosis (50%), spina bifida occulta (40%)

Shortened metacarpals (usually 4th, 5th, or both) (28%)

Bone cysts--phalanges and other bones (46%)

Many others


OTHERS
Lymphomesenteric cysts

Ovarian fibromas or cysts