Teaching Case

A 19-year male patient suffered from road traffic accident and experienced severe pain in the neck. GCS of the patient at presentation was 13/15.

Axial CT images of the brain in bone window shows calcification of the falx (Figure 1) and chunky calcification along the tentorium (Figure 2). Multiple expansile, lytic lesion with scalloped, well-corticated borders were seen in left ramus of the mandible. Coronal CT head in bone window shows that the cystic lesions are occurring in conjunction with an impacted tooth, suggestive of odontogenic keratocyst (Figure 3). Well-defined unilocular cystic lesions were seen in maxilla with a bony smooth or scalloped border and internal calcification. Cortical breach is seen along margins of both lesions.

Background

Gorlin-Goltz syndrome also known as basal cell nevus syndrome is an autosomal dominant disorder, first delineated by Gorlin and Goltz in 1960. The prevalence varies from 1/57,000 to 1/256, and a male-to-female ratio of 1:1 has been reported.

The chief pathogenesis is loss of human patched gene (PTCH1 gene) on chromosome 9, a tumour suppressor gene [1,2].

Clinical Perspective

This syndrome presents with a gamut of signs and syndromes which include odontogenic keratocysts, basal cell carcinomas (BCCs), intracranial ectopic calcifications of the falx cerebri, skeletal abnormalities, hyperkeratosis of palms and soles. Calvarial abnormalities like macrocephaly with frontal bossing and cleft lip/palate. Medulloblastomas, meningiomas, ovarian and cardiac fibromas are among the most commonly reported neoplasms in these people.

Imaging Perspective

The diagnosis is based on diagnostic criteria devised by Evans et al, which were later revised by Kimonis et al [2,3].

Major criteria consist of:

1. More than two basal cell carcinomas or one in patient <20 years old;
2. Odontogenic keratocysts of the jaw;
3. Three or more palmar or plantar pits;
4. Bilamellar calcifications of falx cerebri and tentorium;
5. Bifid or fused, or markedly splayed ribs;
6. First-degree relative with Gorlin-Goltz syndrome.

Minor criteria consist of [3,4]:

1. Macrocephaly;
2. Congenital anomalies (cleft lip or palate, frontal bossing, coarse facies, and moderate or severe hypertelorism);
3. Other skeletal anomalies (Sprengel deformity, marked pectus deformity, and marked syndactyly of the digits);
4. Radiologic anomalies (such as bridging of the sella turcica, vertebral anomalies, modelling defects of the hands and feet, or flame-shaped lucencies of the hands and the feet);
5. Ovarian fibroma or myeloblastoma.

Two (2) major criteria or 1 major and 2 minor criteria are needed to diagnose Gorlin-Goltz syndrome.

Two most conspicuous features – OKC and falx calcification – are only diagnosed properly after radiological examination and thus radiologists play an important role in prompt diagnosis.

OKC in Gorlin-Goltz syndrome are unilocular or multilocular radiolucencies in mandibular body, angle, or ramus. They have smooth or scalloped border. The cysts may cause displacement of teeth and delay in dental development in children. Falx calcification though visible on radiographs are better seen on CT. Brain MRI is the modality of choice in suspected medulloblastoma in a child with the syndrome. Pelvic ultrasound is the modality of choice for ovarian fibromas.

Outcome

The accepted treatment includes:

1. Decompression and marsupialization;
2. Enucleation and reconstruction of bony defect;
3. Enucleation and liquid nitrogen cryotherapy;
4. Block resection with/without preservation of the jaw continuity [3].

Prognosis depends on location and size of the cysts, associated teeth, mucosal involvement. Development of infection is a major hindering factor.

Take Home Message / Teaching Points

Gorlin-Goltz syndrome is an autosomal dominant condition primarily multiple odontogenic keratocysts, basal cell carcinomas and skeletal anomalies. This syndrome can be diagnosed early by radiologist as OKCs are usually one of the first manifestations of the syndrome. Prompt diagnosis and treatment is important for reducing the severity of long-term sequelae of this syndrome.