Nevoid Basal Cell Carcinoma (Gorlin) Syndrome (NBCCS)

Findings

Figure 1: Characteristic calcification of the petroclinoid ligaments and the diaphragma sellae is present.
Figure 2: In addition, there are dural calcifications involving the falx cerebri and tentorium cerebelli.
Figure 3: Soft tissue lesion involving the right scalp is also visualized and corresponds to pathologically proven basal cell carcinoma.
Figure 4: There is subtle parallel orientation of the bodies of the lateral ventricles that suggests dysgenesis of the corpus callosum, a finding that may occur in as many as 10% of patients with NBCCS.


Diagnosis: Nevoid Basal Cell Carcinoma (Gorlin) Syndrome (NBCCS)


NBCCS (Gorlin syndrome) is a rare autosomal dominant disorder characterized by multiple basal cell carcinomas, odontogenic keratocysts of the jaw, palmar/plantar pits, calcification of the falx cerebri, and rib and spine anomalies. Patients with NBCCS have a propensity to develop multiple neoplasms such as basal cell carcinoma (>90%), medulloblastoma (10%), meningioma, and ovarian or cardiac fibromas.

Radiologic evaluation is important in patients suspected of having NBCCS because the identification of a pathogenic mutation is not always possible, and the clinical manifestations may be subtle, especially in children or African Americans. Recognition is also clinically important as these patients are sensitive to ionizing radiation and have been known to develop iatrogenic malignancy as a result of radiation therapy.

Key radiologic features include:
- Extensive calcification of the falx cerebri, tentorium cerebellum, diaphragm sella, or petroclinoid ligaments
- Odontogenic keratocyst of the jaw
- Bifid, splayed, fused, or absent ribs, especially involving the 3rd to 5th ribs
- Scoliosis, hemivertebrae, or fused vertebrae
- Flame-shaped lucencies of the hands or feet
- Scapular abnormalities


Nevoid Basal Cell Carcinoma Syndrome includes two Major critera or one Major and two Minor criteria

Major Criteria
- More than two basal cell carcinomas or one basal cell carcinoma under the age of 20
- Odontogenic keratocysts of the jaw
- Three or more palmar or plantar pits
- Lamellar calcification of the falx cerebri
- Rib Anomalies (bifid, synostosed, hypoplastic)
- First degree relative with NBCCS

Minor Criteria
- Spina bifida occulta or other vertebral anomalies
- Brachymetacarpaly in at least one limb
- Hypertelorism or telcanthus
- Frontal bossing
- Sprengel deformity
- Ovarian fibroma
- Medulloblastoma
- Meningioma
- Flame shaped lucencies of the phalanges
- Bridging of the sella turcica
- Mesenteric cysts
- Cardiac fibroma
- Dysgenesis/agenesis of the corpus callosum