Diagnosis: Gorlin syndrome (nevoid basal cell carcinoma syndrome)

Discussion:
Histology showed tumor nests with basaloid cells, atypical nuclei, melanin pigment and peripheral palisading.

Gorlin syndrome (also called Gorlin-Goltz syndrome) is a rare, autosomal dominant disorder due to mutation of the human patched gene (PTCH1 gene), which provides embryonic structuring and regulatory guidance (Orphanet J Rare Dis 2008 Nov 25;3:32). The mutation causes multiple basal cell carcinomas (BCC) and other associated malignancies, structural anomalies including odontogenic keratocyst of the jaw and skeletal abnormalities including palmar and plantar pits.

The syndrome was first reported by Jarish and White in 1894 and in detail by Gorlin and Goltz in 1960 (N Engl J Med 1960;262:908). The diagnostic criteria was initially outlined by Evans in 1993 and modified by Kimonis et. al. in 1997 (J Med Genet 1993;30:460, Am J Med Genet 1997;69:299). 2 major, or 1 major and 2 minor criteria are essential for diagnosis.

Major criteria:

• Multiple (> 2) basal cell carcinomas or one under 20 years
• Odontogenic keratocysts of the jaws proven by histopathology
• Palmar or plantar pits (3 or more)
• Bilamellar calcification of the falx cerebri
• Bifid, fused or markedly splayed ribs
• First degree relatives with this syndrome

Minor criteria:

• Macrocephaly determined after adjustment for height
• Congenital malformation: cleft lip or palate, frontal bossing, coarse face, moderate of severe hypertelorism
• Other skeletal abnormalities: sprengel deformity, marked pectus deformity, marked syndactyly of the digits
• Radiological abnormalities: bridging of the sella turcica, vertebral anomalies such as hemivertebrae, fusion or elongation of the vertebral bodies, modeling defects of the hands and feet, or flame shaped lucencies of the hands or feet
• Ovarian fibroma
• Medulloblastoma

Life expectancy in patients with Gorlin syndrome is not significantly different from normal, but there are cosmetic problems related to the multiple skin tumors and jaw keratocyst.

Differential diagnosis includes rare skin disorders such as Bazex syndrome, trichoepithelioma papulosum multiplex and Muir-Torre syndrome. Establishing the diagnosis helps prevent fatal consequences from skin cancers and other tumors; referral to a genetic counselor is recommended.

Treatment options for the basal cell carcinomas include excision, laser ablation, cryotherapy, photodynamic therapy, fluorouracil cream and oral retinoids. Regular dermatological check up is advised. Odontogenic cysts are removed surgically. Radiotherapy, nonessential diagnostic Xrays and excessive sun exposure should be avoided.