= NEVOID BASAL CELL CARCINOMA (BCC) SYNDROME = GORLIN-GOLTZ SYNDROME

= syndrome of autosomal dominant inheritance characterized by

1. multiple cutaneous basal cell carcinomas during childhood
2. odontogenic keratocysts of mandible
3. ectopic calcifications
4. skeletal anomalies (midface hypoplasia, frontal bossing, prognathism)

Mean age: 19 years

• up to hundreds of skin-colored pink / tan dome-shaped papules resembling benign nevi; aggressive after puberty; may metastasize
  Distribution: nose, mouth, chest, back; affected by solar + ionizing radiation
• shallow pitlike defects in palms + soles = deficient stratum corneum (85%)
• mental retardation

Genetics: mutation of patched 1 (PTCH) gene that codes for regulatory receptor in the important Sonic hedgehog signaling pathway + acts as a tumor suppressor gene in BCC + medulloblastoma

Association: high incidence of medulloblastoma in children (4–5%); ovarian fibroma (in 17%); cardiac fibroma (in 14%)

• multiple aggressive uni- / multiloculated mandibular >maxillary cystic lesions = odontogenic keratocyst / keratocystic odontogenic tumor (in 75%)
• anomalies of upper 5 ribs:
  • forked = bifid rib (most commonly 4^th rib) in 26%
  • agenesis / supernumerary ribs
  • fusion of adjacent ribs
  • hypo- / dysplastic distorted splayed ribs
• bifid spinous processes, spina bifida
• scoliosis (cervical + upper thoracic)
• hemivertebrae + block vertebrae
• Sprengel deformity (scapula elevated, hypoplastic, bowed)
• deficiency of lateral clavicle
• brachydactyly
• extensive early calcification of falx + tentorium (65%)
• ectopic calcifications of subcutaneous tissue, ovaries, sacrotuberous ligaments, mesentery
• bony bridging of sella turcica
• macrocephaly