CASE 17109 Published on 12.01.2021

Radiological features of Nevoid basal cell carcinoma syndrome

Section

Head & neck imaging

Case Type

Clinical Cases

Authors

El Farouki Ayman1, Benjelloun Laila2, Jiddane Mohamed1, Fikri Meriem1

1. Radiology Department, Ibn Sina Hospital, Baghdad, Iraq

2. Oral Surgery Department, Mohamed V University of Rabat, Morocco, Faculty of Dentistry, Madinat Al Irfane Rabat, Morocco

Patient

21 years, male

Categories
Area of Interest Ear / Nose / Throat, Head and neck ; Imaging Technique Cone beam CT, CT
Clinical History

A 21-year-old patient presented with a complaint of left mandibular swelling for more than 6 months.

Upon extraoral examination, a flattening of the nasal bridge and multiple naevi on the face was noticed. Intraoral examination revealed a swelling in the left mandibular molar region, firm on palpation.

Imaging Findings

A CT was requested. It revealed 6 well-demarcated hypodense cystic lesions and multiple impacted teeth in the jaws (Fig.1). The first lesion was localized in the posterior region of the right maxilla with impacted third molar. The second in the right premolar area of the maxilla with impacted dd .13, 14 (Fig.2). The third lesion was localized in the molar region of the left maxilla with impacted d. 28 (Fig.3). Two other lesions in the left mandible: in the ramus, and in the molar region with impacted d. 38 (Fig.4). The last one was observed in the right mandibular body (Fig.5).

A diagnosis of multiple odontogenic keratocysts (OK) was suspected. It was confirmed by histopathology.

Other radiological abnormalities were detected in the cerebrum: calcification of the falx cerebri, meningeal calcifications (Fig.6), calcification of the tentorium cerebelli and bridging of Sella Turcica (Fig.7).

All these features confirmed the diagnosis of Nevoid basal cell carcinoma syndrome (NBCCS).

Discussion

NBCCS, also known as Gorlin-Goltz syndrome (GGS), is inherited in an autosomal dominant manner [1], with high penetrance and variable expressivity; however, it can arise spontaneously. Individuals with no known affected family members may comprise up to 60% of all affected individuals. In 1960, Gorlin and Goltz [2] delineated a classical triad for the diagnosis: multiple basal cell carcinomas, OKs, and bifid ribs. Later this triad was modified. The diagnosis is based on the Evans et al. [3] diagnostic criteria which were later modified by Kimonis et al. [4] (Fig. 8). Diagnosis is made with the presence of two major criteria, 1 major criterion and molecular confirmation or 1 major and 2 minor criteria. [1,4,6]

Some of the most common findings of the syndrome are discovered through radiography, especially between the tens and twenties. [7,8]

Multiple OKs are among the most representative features of the syndrome. They are seen on both jaws. There may be incidentally noted on routine radiographic examination or be symptomatic in large cysts [8]. The cysts may cause displacement of developing teeth and delayed dental development. There is also continued development of new and recurring cysts until about age 30. [1]

On imaging, OK may show unilocular or multilocular pattern and the cystic spaces may have smooth or scalloped border. [1,6]

Ectopic calcifications of the central nervous system have been also reported as frequent features of the GGS: Calcification of the falx, often described as bilamellar (70–85%) [1,9], is variable and develops with increasing age. CT of the brain is more sensitive than plain x-ray films. Calcification of the tentorium cerebellum is also observed in 22%, and the petroclinoid ligament in 20%. Bridging of the Sella has been reported in 54%.  Spotted meningeal calcifications are rare. These signs may not result in clinical manifestations but are useful in confirming the diagnosis. [1,4,10,11]

NBCC diagnosis can be made based on clinical and radiological findings, but confirmation of the diagnosis by molecular genetic testing is preferable.

A multidisciplinary approach (radiologists, dentists, oral and maxillofacial surgeons, dermatologists, and neurologists) is required for the diagnosis and management of this syndrome. Management is about adequate treatment of cysts and removal of tumours. It is also about prevention from malignancies, especially prevention from exposure to UV light to prevent basal cell carcinoma. [6,12] Long follow-up periods are necessary, in order to minimize secondary morbidities [8,12]

This case reinforces the idea that the radiologist has an important responsibility in the early diagnosis of the NBCCS. He must know at least major criteria and typical skeletal imaging findings (OKs, falx cerebri calcification, bifid ribs...) [11]. When multiple cystic lesions are present, we must think about NBCCS.

Written informed patient consent for publication has been obtained

Differential Diagnosis List
Multiple Odontogenic keratocysts in a NBCCS
Nevoid basal cell carcinoma syndrome
Non-syndromic Odontogenic keratocysts
Multiple dentigerous cysts
Final Diagnosis
Multiple Odontogenic keratocysts in a NBCCS
Case information
URL: https://www.eurorad.org/case/17109
DOI: 10.35100/eurorad/case.17109
ISSN: 1563-4086
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