basal cell nevus syndrome

Definition: Autosomal dominant tumor predisposition syndrome. Nevoid basal cell carcinoma syndrome (NBCC; Gorlin syndrome), an autosomal dominant disorder linked to 9q22.3-q31, and caused by mutations in PTC, the human homologue of the Drosophila patched gene, comprises multiple basal cell carcinomas, keratocysts of the jaw, palmar/plantar pits, spine and rib anomalies and calcification of the falx cerebri.

Digital case (Digital slides)

 HPC:389 : Keratocyst of the maxillary in Gorlin syndrome

Images

 keratocyst

• https://twitter.com/VishwasParekh/status/710856596235149312
• https://twitter.com/SGottesmanMD/status/720802134661312512

Synopsis

 multiple keratocysts

• cutaneous keratocysts
• odontogenic keratocyst / keratocysts of the jaw ( a subtype of odontogenic cysts )

 craniofacial anomalies

• coarse facies
• broad facies
• relative macrocephaly (50%)
• hypertelorism
• frontal bossing (27%)
• downward slanting palpebral fissures
• biparietal bossing
• mild mandibular prognathism
• odontogenic keratocyst of jaws - kerocysts
• strabismus
• lateral displacement of the inner canthi
• hypertelorism
• subconjunctival epithelial cysts
• iris coloboma
• glaucoma
• broad nasal root
• cleft lip
• cleft palate

 visceral malformations

• congenital lung cyst
• lymphomesenteric cysts +/- calcified
• hamartomatous stomach polyps

 palmar pits/plantar pits

 skeletal anomalies

• biparietal bossing
• mandible prognathism
• pectus excavatum
• thumb abnormalities
• occult spina bifida
• bridging of sella turcica
• rib anomalies
  • bifid ribs
  • synostotic ribs
  • hypoplastic ribs

• thoracic deformations
  • pectus deformity (13%)
  • Sprengel deformity (11%)
  • pectus excavatum

• spine anomalies
  • scoliosis
  • kyphoscoliosis
  • abnormal cervical vertebrae

• brachydactyly
• thumb anomalies
• short 4th metacarpal
• short thumb terminal phalanx

 cerebral anomalies

• calcification of the falx cerebri

 pits of palms and soles
 mental retardation
 paternal age effect
 abnormal sensitivity to therapeutic radiation

 skeletal anomalies

• vertebral anomalies
• occult spina bifida
• costal anomalies

 palmar pits
 plantar pits

 cerebrospinal anomaies

• intracranial falx calcification

 tumoral predisposition

• cutaneous basal cell nevi
• cutaneous basal cell carcinomas
• cardiac fibroma
• medulloblastoma
• cardiac tumors (2020522)
• BCNS-associated ovarian fibroma (12239722)
• ovarian fibromata
• ovarian carcinoma
• medulloblastoma

Cytogenetics

 interstitial deletion 9q22.32-q33.2 (14699618)
 familial translocation t(9;17)(q34.11;p11.2) (14699618)

Etiology

 mutations in the human homolog of the Drosophila ’patched’ gene (PTCH) (MIM.601309)

References

 Basal cell nevus syndrome: clinical and genetic diagnosis. García de Marcos JA, Dean-Ferrer A, Arroyo Rodríguez S, Calderón-Polanco J, Alamillos Granados FJ, Poblet E. Oral Maxillofac Surg. 2009 Dec;13(4):225-30. PMID: 19795138

 Manfredi M, Vescovi P, Bonanini M, Porter S. Nevoid basal cell carcinoma syndrome: a review of the literature. Int J Oral Maxillofac Surg. 2004 Mar;33(2):117-24. PMID: 15050066

 Complex karyotypic abnormality in ovarian fibroma associated with Gorlin syndrome. Smith LM, Hu P, Meyer LJ, Coffin CM. Am J Med Genet. 2002 Sep 15;112(1):61-4. PMID: 12239722

 Kimonis VE, Goldstein AM, Pastakia B, Yang ML, Kase R, DiGiovanna JJ, Bale AE, Bale SJ. Clinical manifestations in 105 persons with nevoid basal cell carcinoma syndrome. Am J Med Genet. 1997 Mar 31;69(3):299-308. PMID: 9096761