Ameloblastoma: a neglected criterion for nevoid basal cell carcinoma (Gorlin) syndrome

Ameloblastoma associated with syndromes: A systematic review

Odontogenic lesions have been described in several syndromes. Despite multiple reports of ameloblastoma's association with various syndromes, it has not been added to the diagnostic criteria for any syndrome. Thus, the aim of this systematic review was gathering such cases' data. An electronic search in PubMed Central's database was performed. The search strategy was limited to human studies (case reports and case series), full-text English articles published from first of January 1975 until the end of 2018. Irrelevant articles or articles with inadequate information were omitted. Associated syndrome, patients' age and sex, lesions' location, radiographic features, and treatment modality were collected and analyzed. Ameloblastoma was reported in association with Gorlin syndrome (6 cases), epidermal nevus syndrome (2 cases), Gardner syndrome (2 cases), Simpson-Golabi-Behmel syndrome (1 case), and Williams syndrome (1 case). The commonest associated syndrome was Gorlin syndrome (50%) with maxillary and female predilections. Both cases of epidermal nevus syndrome (ENS) were female with mandibular involvement. In syndromes that odontogenic lesions are one of the diagnostic criteria, it is important to rule out ameloblastic changes. Although the relationship between ameloblastoma and these syndromes is not well known, any related information may be helpful in understanding the pathogenesis and the nature of this neoplasm.

Keratocystic odontogenic tumors related to Gorlin-Goltz syndrome: A clinicopathological study

BACKGROUND

Assess clinicopathological features of patients with keratocystic odontogenic tumor (KCOT) associated with Gorlin-Goltz syndrome in our institution from 2004 to 2015.

METHOD

After histopathological analyses of KCOT related to Gorlin-Goltz syndrome, 7 patients were assessed. These patients presented a total of 15 primary and 2 recurrent KCOT.

RESULTS

All patients presented a multiple KCOT, and 13 lesions were located in mandible (77%) and 4 (23%) in maxilla. Most of the tumors presented a unilocular pattern (71%) and had tooth association (88%). Four patients (57%) were in the age group of 10-19 years and three patients (43%) were in the age group of 20-29 years. There were four male and three female patients.

CONCLUSION

KCOT is a frequent manifestation of Gorlin-Goltz syndrome and can be its first sign, mainly in young patients. The four patients presented with two lesions (57%) and three lesions in three patients (43%).

Oral mucosal stigmata in hereditary-cancer syndromes: From germline mutations to distinctive clinical phenotypes and tailored therapies

Numerous familial tumor syndromes are associated with distinctive oral mucosal findings, which may make possible an early diagnosis as an efficacious marker for the risk of developing visceral malignancies. In detail, Familial Adenomatous Polyposis (FAP), Gardner syndrome, Peutz-Jeghers syndrome, Cowden Syndrome, Gorlin Syndrome, Lynch/Muir-Torre Syndrome and Multiple Endocrine Neoplasia show specific lesions of the oral mucosa and other distinct clinical and molecular features. The common genetic background of the above mentioned syndromes involve germline mutations in tumor suppressor genes, such as APC, PTEN, PTCH1, STK11, RET, clearly implied in both ectodermal and mesodermal differentiation, being the oral mucosal and dental stigmata frequently associated in the specific clinical phenotypes. The oral and maxillofacial manifestations of these syndromes may become visible several years before the intestinal lesions, constituting a clinical marker that is predictive for the development of intestinal polyps and/or other visceral malignancies. A multidisciplinary approach is therefore necessary for both clinical diagnosis and management of the gene-carriers probands and their family members who have to be referred for genetic testing or have to be investigated for the presence of visceral cancers.

Skeletal stigmata as keys to access to the composite and ancient Gorlin-Goltz syndrome history: The Egypt, Pompeii and Herculaneum lessons

There are several genetic diseases with a wide spectrum of congenital bone stigmata in association to cutaneous and visceral benign and malignant neoplasms. Gorlin-Goltz syndrome, also named nevoid basal cell carcinoma syndrome, is an autosomal dominant systemic disease with almost complete penetrance and high intra-familial phenotypic variability, caused by germline mutations of the gene PTCH1. The syndrome is characterized by unusual skeletal changes and high predisposition to the development of multiple basal cell carcinomas, odontogenic keratocysts tumors and other visceral tumors. The Gorlin syndrome, clinically defined as distinct syndrome in 1963, existed during Dynastic Egyptian times, as revealed by a costellation of skeletal findings compatible with the syndrome in mummies dating back to 3000years ago and, most likely, in the ancient population of Pompeii. These paleogenetic and historical evidences, together with the clinical and biomolecular modern evidences, confirm the quite benign behavior of the syndrome and the critical value of the multiple and synchronous skeletal anomalies in the recognition of these rare and complex genetic disease.

Signs and genetics of rare cancer syndromes with gastroenterological features

Although the genetic bases of most hereditary cancer syndromes are known, and genetic tests are available for them, the incidence of the most rare of these syndromes is likely underestimated, partially because the clinical expression is neither fully understood nor easily diagnosed due to the variable and complex expressivity. The clinical features of a small pool of rare cancer syndromes include gastroenterological signs, though not necessarily tumors, that could require the intervention of a gastroenterologist during any of the phases of the clinical management. Herein we will attempt to spread the knowledge on these rare syndromes by summarizing the phenotype and genetic basis, and revising the peculiar gastroenterological signs whose underlying role in these rare hereditary cancer syndromes is often neglected. Close collaboration between geneticists and gastroenterologists could facilitate both the early identification of patients or relatives at-risk and the planning of multidisciplinary and tailored management of these subjects.

A systematic review of the literature of nevoid basal cell carcinoma syndrome affecting East Asians and North Europeans

OBJECTIVE

To compare, by systematic review, North European and East Asian consecutive case series of nevoid basal cell carcinoma syndrome (NBCCS).

STUDY DESIGN

A systematic review of the literature was performed for all consecutive case series of NBCCS, which included keratocystic odontgenic tumors (KCOTs) arising in North European and East Asian communities. The clinical and radiologically apparent features were identified and synthesized, and a meta-analysis was performed.

RESULTS

East Asian reports were significantly more "proband only" compared with North European reports. Significant differences between these 2 communities were observed for 5 of the 6 major features and 11 of the 27 minor features. With regard to the major NBCCS features, the North Europeans displayed significantly more frequent basal cell carcinomas, calcified falx cerebri, palmar and plantar pits, and a family history, whereas the East Asians displayed KCOTs significantly more frequently. With regard to minor features, East Asians displayed significantly more frequent cleft lips and palates and hypertelorism.

CONCLUSIONS

East Asians displayed multiple KCOTs and cleft lips and palates more frequently compared with North Europeans.

Skeletal and cranio-facial signs in Gorlin syndrome from ancient Egypt to the modern age: sphenoid asymmetry in a patient with a novel PTCH1 mutation

Gorlin syndrome is an autosomal dominant disorder linked to PTCH1 mutation, identified by a collection of clinical and radiologic signs. We describe the case of a family in which father and son fulfilled clear cut diagnostic criteria for Gorlin syndrome including multiple basal cell carcinomas, keratocystic odontogenic tumors, atypical skeletal anomalies and a novel PTCH1 germline mutation (c.1041delAA). Craniofacial and other skeletal anomalies displayed at 3D and helical CT scan were: macrocephaly, positional plagiocephaly, skull base and sphenoid asymmetry, bifidity of multiple ribs and giant multilocular odontogenic jaw cysts. Extensive multilamellar calcifications were found in falx cerebri, tentorium, falx cerebelli and in the atlanto-occipital ligament. The inclusion of bifid ribs as a novel major criteri may be useful for the recognition and characterization of misdiagnosed cases.

Transcriptional profiles of SHH pathway genes in keratocystic odontogenic tumor and ameloblastoma

BACKGROUND

Sonic hedgehog (SHH) pathway activation has been identified as a key factor in the development of many types of tumors, including odontogenic tumors. Our study examined the expression of genes in the SHH pathway to characterize their roles in the pathogenesis of keratocystic odontogenic tumors (KOT) and ameloblastomas (AB).

METHODS

We quantified the expression of SHH, SMO, PTCH1, SUFU, GLI1, CCND1, and BCL2 genes by qPCR in a total of 23 KOT, 11 AB, and three non-neoplastic oral mucosa (NNM). We also measured the expression of proteins related to this pathway (CCND1 and BCL2) by immunohistochemistry.

RESULTS

We observed overexpression of SMO, PTCH1, GLI1, and CCND1 genes in both KOT (23/23) and AB (11/11). However, we did not detect expression of the SHH gene in 21/23 KOT and 10/11 AB tumors. Low levels of the SUFU gene were expressed in KOT (P = 0.0199) and AB (P = 0.0127) relative to the NNM. Recurrent KOT exhibited high levels of SMO (P = 0.035), PTCH1 (P = 0.048), CCND1 (P = 0.048), and BCL2 (P = 0.045) transcripts. Using immunolabeling of CCND1, we observed no statistical difference between primary and recurrent KOT (P = 0.8815), sporadic and NBCCS-KOT (P = 0.7688), and unicystic and solid AB (P = 0.7521).

CONCLUSIONS

Overexpression of upstream (PTCH1 and SMO) and downstream (GLI1, CCND1 and BCL2) genes in the SHH pathway leads to the constitutive activation of this pathway in KOT and AB and may suggest a mechanism for the development of these types of tumors.

PTCH1 gene mutations in Keratocystic odontogenic tumors: a study of 43 Chinese patients and a systematic review

BACKGROUND

The keratocystic odontogenic tumor (KCOT) is a locally aggressive cystic jaw lesion that occurs sporadically or in association with nevoid basal cell carcinoma syndrome (NBCCS). PTCH1, the gene responsible for NBCCS, may play an important role in sporadic KCOTs. In this study, we analyzed and compared the distribution pattern of PTCH1 mutations in patients with sporadic and NBCCS-associated KCOTs.

METHODS

We detected PTCH1 mutations in 14 patients with NBCCS-associated KCOTs and 29 patients with sporadic KCOTs by direct sequencing. In addition, five electronic databases were searched for studies detecting PTCH1 mutations in individuals with NBCCS-associated or sporadic KCOTs, published between January 1996 and June 2013 in English language.

RESULTS

We identified 15 mutations in 11 cases with NBCCS-associated KCOTs and 19 mutations in 13 cases with sporadic KCOTs. In addition, a total of 204 PTCH1 mutations (187 mutations from 210 cases with NBCCS-associated and 17 mutations from 57 cases with sporadic KCOTs) were compiled from 78 published papers.

CONCLUSIONS

Our study indicates that mutations in transmembrane 2 (TM2) are closely related to the development of sporadic KCOTs. Moreover, for the early diagnosis of NBCCS, a genetic analysis of the PTCH1 gene should be included in the new diagnostic criteria.

Current concepts and occurrence of epithelial odontogenic tumors: I. Ameloblastoma and adenomatoid odontogenic tumor

Ameloblastomas and adenomatoid odontogenic tumors (AOTs) are common epithelial tumors of odontogenic origin. Ameloblastomas are clinico-pathologically classified into solid/multicystic, unicystic, desmoplastic, and peripheral types, and also divided into follicular, plexiform, acanthomatous, granular types, etc., based on their histological features. Craniopharyngiomas, derived from the remnants of Rathke's pouch or a misplaced enamel organ, are also comparable to the odontogenic tumors. The malignant transformation of ameloblastomas results in the formation of ameloblastic carcinomas and malignant ameloblastomas depending on cytological dysplasia and metastasis, respectively. AOTs are classified into follicular, extrafollicular, and peripheral types. Ameloblastomas are common, have an aggressive behavior and recurrent course, and are rarely metastatic, while AOTs are hamartomatous benign lesions derived from the complex system of the dental lamina or its remnants. With advances in the elucidation of molecular signaling mechanisms in cells, the cytodifferentiation of epithelial tumor cells in ameloblastomas and AOTs can be identified using different biomarkers. Therefore, it is suggested that comprehensive pathological observation including molecular genetic information can provide a more reliable differential diagnosis for the propagation and prognosis of ameloblastomas and AOTs. This study aimed to review the current concepts of ameloblastomas and AOTs and to discuss their clinico-pathological features relevant to tumorigenesis and prognosis.

Diagnostic and pathogenetic role of café-au-lait macules in nevoid basal cell carcinoma syndrome

Café au lait spots (CALS) are common dermatologic findings that can at the same time arise in a variety of pathologic conditions such as Neurofibromatosis type 1 (NF1), together with numerous hereditary syndromes for which they represent either diagnostic criteria or associated elements (McCune Albright, Silver-Russell, LEOPARD, Ataxia-Telangiectasia). A review of the literature also revealed two cases of association with NBCCS. We report here the case of a female proband with CALS associated to Nevoid Basal Cell Carcinoma Syndrome (NBCCS) with known PTCH1 germline mutation (C.1348-2A>G) who had been misdiagnosed with NF1 in her childhood because of 5 CALS and cutaneous nodules. The patient presented a giant cell tumor of the skin, palmar and calcaneal epidermoidal cystic nodules, odontogenic keratocystic tumors and deformity of the jaw profile. Her family history brought both her brother and father to our attention because of the presence of KCOTs diagnosed at early age: after genetic testing, the same PTCH1 germline mutation was identified in the three family members. Clinical criteria are used for discerning NF1 diagnosis (size, number and onset age), while there are no definite guidelines concerning CALS except for their presence. In our experience, we have noted an association of CALS with NBCCS; this seems interesting because we already know clinical criteria are a dynamic entity and can be modified by epidemiologic evidences.