Clear Cell Odontogenic Carcinoma: First Report of Novel EWSR1-CREM Fusion Gene in Case of Long-Term Misdiagnosis.

Clear Cell odontogenic Carcinomas (CCOC) are rare, aggressive malignant odontogenic tumours which are often misdiagnosed as benign odontogenic tumours due to the non-specific histologic appearance, and benign early clinical presentation. However, due to their propensity to metastasize, the best outcomes are experienced with they are diagnosed early and treated aggressively. In this paper, we present a case of a CCOC misdiagnosed as a clear cell calcifying epithelial odontogenic tumour which was only found to be a CCOC after cervical node metastasis. The original diagnosis was questioned and confirmed to be a CCOC by identification of the chromosomal translocation EWSR1 on fluorescence in situ hybridization. This has recently been described in CCOC and a wide variety of other mesenchymal and epithelial neoplasms. Previous reports have demonstrated EWSR1-ATF1 and EWSR1-CREB1 fusions in CCOC. Next generation sequencing of this case demonstrated the EWSR1-CREM fusion gene which has not been previously reported for CCOC. CREM fusion proteins have only recently been found in several tumour types including the closely associated hyalinizing clear cell carcinoma of salivary glands. This is discussed in this paper, and the role of the discovery of the CREM fusion protein in CCOC adds to your understating of the role of CREM in oncogenesis, and the possible link between CCOCs and hyalinizing clear cell carcinomas.

Molecular findings in maxillofacial bone tumours and its diagnostic value.

According to the WHO, mesenchymal tumours of the maxillofacial bones are subdivided in benign and malignant maxillofacial bone and cartilage tumours, fibro-osseous and osteochondromatous lesions as well as giant cell lesions and bone cysts. The histology always needs to be evaluated considering also the clinical and radiological context which remains an important cornerstone in the classification of these lesions. Nevertheless, the diagnosis of maxillofacial bone tumours is often challenging for radiologists as well as pathologists, while an accurate diagnosis is essential for adequate clinical decision-making. The integration of new molecular markers in a multidisciplinary diagnostic approach may not only increase the diagnostic accuracy but potentially also identify new druggable targets for precision medicine. The current review provides an overview of the clinicopathological and molecular findings in maxillofacial bone tumours and discusses the diagnostic value of these genetic aberrations.

Biallelic PTCH1 Inactivation Is a Dominant Genomic Change in Sporadic Keratocystic Odontogenic Tumors.

Keratocystic odontogenic tumors (KCOTs) are locally aggressive odontogenic neoplasms with recurrence rates of up to 60%. Approximately 5% of KCOTs are associated with nevoid basal cell carcinoma (Gorlin) syndrome and 90% of these show genomic inactivation of the PTCH1 gene encoding Patched 1. Sporadic KCOTs reportedly have PTCH1 mutations in 30% of cases, but previous genomic analyses have been limited by low tumor DNA yield. The aim of this study was to identify recurrent genomic aberrations in sporadic KCOTs using a next-generation sequencing panel with complete exonic coverage of sonic hedgehog (SHH) pathway members PTCH1, SMO, SUFU, GLI1, and GLI2. Included were 44 sporadic KCOTs from 23 female and 21 male patients with a median age of 50 years (range, 10 to 82 y) and located in the mandible (N=33) or maxilla (N=11). Sequencing identified PTCH1 inactivating mutations in 41/44 (93%) cases, with biallelic inactivation in 35 (80%) cases; 9q copy neutral loss of heterozygosity targeting the PTCH1 locus was identified in 15 (34%) cases. No genomic aberrations were identified in other sequenced SHH pathway members. In summary, we demonstrate PTCH1 inactivating mutations in 93% of sporadic KCOTs, indicating that SHH pathway alterations are a near-universal event in these benign but locally aggressive neoplasms. The high frequency of complete PTCH1 loss of function may provide a rational target for SHH pathway inhibitors to be explored in future studies.

Clinicopathologic study on a rare variant of ameloblastoma with basal cell features.

OBJECTIVES: To investigate the clinical features, pathologic manifestations, and biologic behaviors of a variant of ameloblastoma with basal cell features (AM-BC). MATERIALS AND METHODS: Following retrospective review of the clinical and pathological data of six cases of AM-BC, we described their histological and immunohistochemical (IHC) features and discussed the biologic behaviors, prognoses, pathogenesis, and clinical relevance of AM-BC. Direct sequencing of polymerase chain reaction products was also performed in all cases. RESULTS: The six cases of AM-BC involved four women and two men, aged 22-82 years. Four lesions occurred in the maxilla and two in the mandible. Histologically, the basal cells tended to be arranged as unequally sized follicles, strands, or cords of odontogenic epithelium in the connective tissue stroma. Little or no stellate reticulum was present in the central portion of the nest. Expression of CKs was consistent with other histological variants of ameloblastoma (AM), but AM-BC had significantly higher p53 and Ki-67 (p < 0.05) labeling indices than other histological variants of AM. Two patients had BRAF gene mutations. CONCLUSION: Ameloblastoma with basal cell features is a very rare variant of AM. Our study showed the differences and relationships that exist between AM-BC and other variants of AM, which could enhance understanding of AM-BC.

Suppression of SESN1 reduces cisplatin and hyperthermia resistance through increasing reactive oxygen species (ROS) in human maxillary cancer cells.

INTRODUCTION: Cisplatin is used as a standard chemotherapeutic agent for head and neck cancer treatment. However, some head and neck cancers have cisplatin resistance, leading to difficulty in treatment and poor prognosis. Overcoming cisplatin resistance remains an important strategy to improve prognoses for head and neck cancer patients. OBJECTIVE: Elucidation of the mechanisms underlying cisplatin resistance can suggest novel targets to enhance the anticancer effects of cisplatin for treating head and neck cancers. MATERIAL AND METHODS: We used a cisplatin-resistant human maxillary cancer cell line, IMC-3CR to analyse the cisplatin resistance mechanisms. Cisplatin-induced genes were analysed in IMC-3CR cells using PCR array. Among the genes with expression increased by cisplatin, we specifically examined SESN1. SESN family reportedly regenerates peroxiredoxin and suppresses oxidative DNA injury by reactive oxygen species (ROS), which can be induced by chemotherapeutic agents such as cisplatin, radiation, and hyperthermia. The function of SESN1 in cisplatin resistance and ROS generation were analysed using specific RNAi. RESULTS: Results show that SESN1 was induced by cisplatin treatment in IMC-3CR cells. Suppression of SESN1 by RNAi induced apoptosis and reduced cell viability through enhancement of ROS after cisplatin treatment. Moreover, suppression of SESN1 enhanced the cell-killing effects of hyperthermia with increased ROS, but did not affect the cell-killing effects of radiation. CONCLUSIONS: This study demonstrated the participation of SESN1 in cisplatin and hyperthermia resistance of human head and neck cancers. SESN1 is a novel molecular target to overcome cisplatin resistance and hyperthermia resistance and improve head and neck cancer treatment.

A lesion categorized between ghost cell odontogenic carcinoma and dentinogenic ghost cell tumor with CTNNB1 mutation.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm characterized by the presence of ghost cells. It is considered to arise either de novo or from a preexisting benign precursor, calcifying odontogenic cyst (COC), or dentinogenic ghost cell tumor (DGCT). We report a case of a 44-year-old Japanese male with a left maxillary tumor. The patient received treatment to resect the left maxillary cyst 25 years prior; however, the details were uncertain. The tumor was resected with clear margins. Taken together with the results of histological and immunohistochemical examinations, the tumor was categorized between GCOC and DGCT, and we diagnosed the tumor as GCOC suggesting similarity to DGCT. Further, we focused on CTNNB1, which encodes ß-catenin and is frequently mutated in COCs. In this tumor, we identified CTNNB1 Ser33Cys, one of the mutations typically found in COCs. This finding suggests that CTNNB1 is a common target for the pathogenesis of tumors accompanied by ghost cells.

Genetic Analysis of Giant Cell Lesions of the Maxillofacial and Axial/Appendicular Skeletons.

PURPOSE: To compare the genetic and protein expression of giant cell lesions (GCLs) of the maxillofacial (MF) and axial/appendicular (AA) skeletons. We hypothesized that when grouped according to biologic behavior and not simply by location, MF and AA GCLs would exhibit common genetic characteristics. MATERIALS AND METHODS: This was a prospective and retrospective study of patients with GCLs treated at Massachusetts General Hospital from 1993 to 2008. In a preliminary prospective study, fresh tissue from 6 aggressive tumors each from the MF and AA skeletons (n = 12 tumors) was obtained. RNA was extracted and amplified from giant cells (GCs) and stromal cells first separated by laser capture microdissection. Genes highly expressed by GCs and stroma at both locations were determined using an Affymetrix GeneChip analysis. As confirmation, a tissue microarray (TMA) was created retrospectively from representative tissue of preserved pathologic specimens to assess the protein expression of the commonly expressed genes found in the prospective study. Quantification of immunohistochemical staining of MF and AA lesions was performed using Aperio image analysis to determine whether immunoreactivity was predictive of aggressive or nonaggressive behavior. RESULTS: Five highly ranked genes were found commonly in GCs and stroma at each location: matrix metalloproteinase-9 (MMP-9), cathepsin K (CTSK), T-cell immune regulator-1 (TCIRG1), C-type lectin domain family-11, and zinc finger protein-836. MF (n = 40; 32 aggressive) and AA (n = 48; 28 aggressive) paraffin-embedded tumors were included in the TMA. The proteins CTSK, MMP-9, and TCIRG1 were confirmed to have abundant expression within both MF and AA lesions. Only the staining levels for TCIRG1 within the GCs predicted the clinical behavior of the MF lesions. CONCLUSIONS: MMP-9, CTSK, and TCIRG1 are commonly expressed by GCLs of the MF and AA skeletons. This supports the hypothesis that these lesions are similar but at different locations. TCIRG1 has not been previously associated with GCLs and could be a potential target for molecular diagnosis and/or therapy.

Li-Fraumeni syndrome presenting as mucosal melanoma: Case report and treatment considerations.

BACKGROUND: Li-Fraumeni syndrome (LFS) is a familial cancer predisposition associated with a germline mutation in TP53. Patients with LFS are at risk of developing malignancies and require comprehensive screening. We describe an index case of LFS presenting with mucosal melanoma. METHODS: A 21-year-old woman presented with a left maxillary mucosal lesion and a left neck mass. Biopsies revealed metastatic mucosal melanoma, which is a pathology previously unreported in LFS families. Genetic testing revealed LFS, with a germline TP53 mutation, and pedigree analysis identified 9 first-degree and second-degree relatives with hematologic malignancies. RESULTS: The patient underwent a maxillectomy and left neck dissection, followed by adjuvant radiotherapy. At 30-month follow-up, there was no evidence of local, regional, or distant failure, nor did she develop a second primary tumor. CONCLUSION: This represents the first reported case of LFS associated with mucosal melanoma. Treatment considerations, specifically the risks of adjuvant therapy in LFS, are discussed. © 2016 Wiley Periodicals, Inc. Head Neck 39: E20-E22, 2017.

BRAFV600E Mutation in Melanotic Neuroectodermal Tumor of Infancy: Toward Personalized Medicine?

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that primarily affects the maxilla of infants during their first year of life. Complete resection is the conventional treatment and recurrence rates vary from 10% to 60%. The recurrent tumors grow more aggressively and can invade other anatomic structures, such as the nasal cavity, the orbit, and the skull base. The aggressive behavior of MNTIs may require radical resection, which may not be possible in some cases because of its rapid and invading growth together with invasion of vital structures. In these situations, adjunct radiotherapy or chemotherapy has been used. However, as there are no conclusive data regarding the molecular profile of this tumor, currently there is no targeted therapy that may be used in the treatment of selected aggressive cases. On the basis of MNTI similarities with melanomas, such as derivation from the neural crest cells and presence of large melanin-containing cells, we hypothesized that MNTIs also may harbor the BRAFV600E oncogenic mutation. We show for the first time that this important pediatric tumor may harbor the oncogenic BRAFV600E mutation, providing the first insights to their personalized treatment.

Suppression of Poly(rC)-Binding Protein 4 (PCBP4) reduced cisplatin resistance in human maxillary cancer cells.

Cisplatin plays an important role in the therapy for human head and neck cancers. However, cancer cells develop cisplatin resistance, leading to difficulty in treatment and poor prognosis. To analyze cisplatin-resistant mechanisms, a cisplatin-resistant cell line, IMC-3CR, was established from the IMC-3 human maxillary cancer cell line. Flow cytometry revealed that, compared with IMC-3 cells, cisplatin more dominantly induced cell cycle G2/M arrest rather than apoptosis in IMC-3CR cells. That fact suggests that IMC-3CR cells avoid cisplatin-induced apoptosis through induction of G2/M arrest, which allows cancer cells to repair damaged DNA and survive. In the present study, we specifically examined Poly(rC)-Binding Protein 4 (PCBP4), which reportedly induces G2/M arrest. Results showed that suppression of PCBP4 by RNAi reduced cisplatin-induced G2/M arrest and enhanced apoptosis in IMC-3CR cells, resulting in the reduction of cisplatin resistance. In contrast, overexpression of PCBP4 in IMC-3 cells induced G2/M arrest after cisplatin treatment and enhanced cisplatin resistance. We revealed that PCBP4 combined with Cdc25A and suppressed the expression of Cdc25A, resulting in G2/M arrest. PCBP4 plays important roles in the induction of cisplatin resistance in human maxillary cancers. PCBP4 is a novel molecular target for the therapy of head and neck cancers, especially cisplatin-resistant cancers.

[Gorlin syndrome in the paediatric age]. / Síndrome de Gorlin en la edad pediátrica.

INTRODUCTION: Gorlin syndrome (GS) is a disorder transmitted by dominant autosomal inheritance associated to mutations in PTCH1, the main characteristic of which is the appearance of basal cell carcinomas, together with skeletal abnormalities, odontogenic keratocysts and intracranial tumours. CASE REPORT: A girl aged 3 years and 10 months, who was admitted due to acute ataxia. Some of the more striking features in the patient's personal history include psychomotor retardation and a family history of suspected GS in the mother as a result of a maxillary cyst. An examination revealed macrocephaly with a prominent forehead and hypertelorism, as well as nevus. A genetic study for GS was requested, in which mutation c.930delC was detected in exon 6 of the PTCH1 gene in heterozygosis. CONCLUSIONS: In GS there is an increase in the likelihood of developing basal cell carcinomas and strict dermatological monitoring is necessary. A clinical neurological follow-up and also magnetic resonance imaging scans are needed for an early diagnosis of intracranial tumours, especially in the case of medulloblastomas. Odontogenic keratocysts, other skin disorders, and cardiac and ovarian fibromas are characteristic, as are skeletal abnormalities, which require regular clinical and neuroimaging controls and treatment if needed, but radiation must be avoided. GS is a rare disorder, but it must be suspected in the presence of characteristic alterations. It requires a multidisciplinary follow-up, and it is also necessary to establish a protocol on how to act so as to allow early diagnosis and treatment of the potentially severe complications deriving from this disease.

TITLE: Sindrome de Gorlin en la edad pediatrica.Introduccion. El sindrome de Gorlin (SG) es un trastorno de herencia autosomica dominante asociado a mutaciones en el gen PTCH1, cuya principal caracteristica es la aparicion de carcinomas basocelulares, unido a anomalias esqueleticas, queratoquistes odontogenicos y tumores intracraneales. Caso clinico. Niña de 3 años y 10 meses, ingresada por ataxia aguda. Destacan como antecedentes personales retraso psicomotor y como antecedentes familiares la sospecha de SG en la madre por quiste maxilar. En la exploracion, se aprecia macrocefalia con frente prominente e hipertelorismo, asi como nevo. Se solicita estudio genetico de SG, en el que se detecta la mutacion c.930delC en el exon 6 del gen PTCH1 en heterocigosis. Conclusiones. En el SG hay un aumento de la susceptibilidad al desarrollo de carcinomas basocelulares y es preciso un estrecho control dermatologico. Es necesario un seguimiento neurologico clinico y de imagen, mediante resonancia magnetica, para el diagnostico precoz de tumores intracraneales, fundamentalmente el meduloblastoma. Tambien son caracteristicos los queratoquistes odontogenicos, otras alteraciones cutaneas, fibromas cardiacos y ovaricos, asi como anomalias esqueleticas, que precisan controles clinicos y de imagen periodicos, y tratamiento en caso de ser necesarios, pero debe evitarse la radiacion. El SG es un trastorno poco frecuente, que se debe sospechar ante la presencia de alteraciones caracteristicas. Es necesario un seguimiento multidisciplinar, asi como establecer un protocolo de actuacion, para un temprano diagnostico y tratamiento de las complicaciones potencialmente graves derivadas de esta enfermedad.

Managing local swelling following intratumoral electro-chemo-gene therapy.

Delivering genes and other materials directly into the tumor tissue causes specifically localized and powerfully enhanced efficacy of treatments; however, these specific effects can cause rapid, drastic changes in the appearance, texture, and consistency of the tumor. These changes complicate clinical response measurements which can confound the results and render recurring treatments difficult to perform and clinical response measurements nearly impossible to obtain accurately. One of the complicating issues is local swelling. Here, we demonstrate how swelling caused by intratumoral gene treatments can confound the clinical results and impede further treatments, and we demonstrate an easy technique to help overcome this potential hurdle.

Li-Fraumeni syndrome: a case report.

INTRODUCTION: Li-Fraumeni syndrome (LFS) is a very rare familial disease with the predisposition to the development of malignant tumors, such as osteosarcoma, breast cancer, brain neoplasm, leukemia, and adrenal tumors. Inheritance is autosomal dominant and is caused by heterozygous mutations in the p53 gene. The diagnosis is based on clinical criteria: a person under the age of 45 years suffering from sarcoma, the closest relative younger than 45 years diagnosed with cancer and a relative of the first or second degree, which is up to 45 years, was diagnosed with cancer and was diagnosed with sarcoma at any age. CASE REPORT: The presented family with three members diagnosed with malignant disease typical for LFS suggests the need to carefully follow those diagnosed with LFS related tumor. A 24-year-old man diagnosed and treated for osteosarcoma of the maxilla died in the first year. His younger brother was submitted to surgery due to osteosarcoma of the mandible three years later, and a year later in his 24 year he had no signs of locoregional recurrence. Their mother was operated in 1996 for glioblastoma multiform brain cancer and ductal carcinoma, and died two years later at the age of 33. CONCLUSION: The presented family highlights the need for careful examination, inspection and notification of the risks of family members diagnosed with LFS related tumors.

Gene polymorphism of interleukin-1 alpha and beta in keratocystic odontogenic tumors.

AIM AND BACKGROUND: Odontogenic keratocysts have a different growth mechanism and biologic behavior in comparison with more common dentigerous and radicular cysts. It was reclassified as keratocystic odontogenic tumor (KCOT). The proliferative activity of the epithelial cells of KCOT has a close relationship with tissue levels of interleukin-1 (IL-1). Moreover, IL-1 increases the expression of several matrix metalloproteinases in the fibroblasts of adjacent stroma and activates the osteoclastogenesis process. So it plays an important role in the activity, spread, and local aggressiveness of this tumor. Therefore, it seems that the gene polymorphism of the cytokines of the IL-1 family is influential in the pathogenesis of KCOT and the patients' susceptibility to disease. METHOD: A total of 38 blood samples of patients suffering from KCOT and 150 blood samples of healthy patients were assessed using PCR-SSP. The blood samples were assessed for the following polymorphisms: interleukin-1 alpha (-889) and interleukin-1 beta (-511). Following up the patients, we found six recurrent and one syndromic cases. FINDINGS: By comparing the case and control groups, we observed the significant dominance of allele T over C, and genotype TT over CC and CT in IL-1α, although no significant difference was seen in the allele frequency and genotypes regarding IL-1ß. CONCLUSION: The function of IL-1α has a significant relationship with KCOT. Its effective genotype associated with pathogenesis, growth, local invasion, and recurrence is TT.

Unicystic ameloblastoma associated with the novel K729M PTCH1 mutation in a patient with nevoid basal cell carcinoma (Gorlin) syndrome.

Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by a very wide spectrum of clinical signs and symptoms. Here, we report an unusual case of NBCCS in a 38-year-old man with an early onset of clinical signs and symptoms and an associated unicystic ameloblastoma, histopathologically showing basaloid differentiation and intraluminal growth. The odontogenic tumor was surgically enucleated and recurred at the follow-up at 14 months. The proband and his child were identified as gene carriers of the novel K729M PTCH1 missense mutation; other first- and second-degree relatives presented clinical features of NBCCS. Only five other cases of association between ameloblastoma and NBCCS have been reported so far, suggesting that PTCH1 missense mutation might take part in the pathogenesis of keratocystic odontogenic tumors (KCOTs) as well as ameloblastomas.

Basal cell carcinoma arising in association with a maxillary keratocyst in a patient with Gorlin-Goltz syndrome. Report of a case.

INTRODUCTION: Gorlin-Goltz syndrome, also known as nevoid basal cell carcinoma syndrome, is an autosomal dominant inherited disorder which is characterized by the presence of multiple basal cell carcinomas, maxillary keratocysts, and musculoskeletal anomalies. CASE REPORT: We present a case of a patient suffering from Gorlin-Goltz syndrome who developed an intraosseous basal cell carcinoma associated with a recurrent maxillary keratocyst. To our knowledge, this is the first case of malignant transformation of a keratocyst into a basal cell carcinoma described in the literature. CONCLUSION: This case highlights the importance of careful histologic examination of keratocysts excised in patients suffering from Gorlin-Goltz syndrome.

Nevoid basal cell carcinoma syndrome.

Gorlin syndrome is an autosomal dominantly inherited disorder that results in numerous basal cell carcinomas as well as a number of other facial and skeletal findings. We present a patient with many classic features and review some of the treatment options available for these patients.

Ewing's family of tumors of the sinonasal tract and maxillary bone.

The Ewing's family of tumors (EFT) are malignant neoplasms affecting children and young adults. Most cases arise in the long bones or the pelvis. Primary EFT of head and neck is uncommon and primary sinonasal EFT is even rarer. Previous studies have not focused on the sinonasal region specifically, and the published literature on sinonasal EFT consists of sporadic case reports. Fourteen cases of sinonasal EFT were available and had H&Es for review and immunohistochemical stains for CD99, S100, keratins, synaptophysin and desmin. FISH or RT-PCR was performed for EWSR1 abnormalities on 8 cases. The 14 identified patients included 5 males and 9 females, ranging from 7-70 years of age (mean 32.4 years). Tumors involved nasal cavity (5), sinuses (5) or both (4). Five patients had dural, orbital or brain involvement. The majority involved bone radiologically and/or microscopically. All cases were composed of small cells with variable cytoplasmic clearing. Focal or prominent nesting was noted in most cases. All cases were positive for CD99. Keratins (AE1/3 and/or CAM5.2), S100 and synaptophysin were positive in 4, 3 and 5 cases, respectively. All cases were negative for desmin. The 8 cases tested by FISH or RT-PCR were positive for EWSR1 abnormalities. Follow-up in 8 patients ranged from 1-168 months (average 11.3 m) showing 1 death due to metastatic disease, 1 death due to local disease, 1 patient alive with metastases and 5 patients disease-free at last follow-up. Interestingly, however, an analysis of the literature suggests a better prognosis for sinonasal EFT than EFT overall.

Clonality analysis of giant cell lesions of the jaws.

Despite the importance of clonality to understand the pathogenesis and progression of tumors, it has not been investigated yet in giant cell lesions of the jaws. The aim of this study was to analyze the clonality of peripheral giant cell lesions (PGCL) and central giant cell lesions (CGCL) of the jaws. Six samples of PGCL and 5 samples of CGCL were analyzed in this study using the polymorphic human androgen receptor locus (HUMARA) assay. Three out of the 5 samples of the CGCL and 3 out of 6 samples of PGCL exhibited a monoclonal pattern. Our findings demonstrate that some giant cell lesions of the jaws are clonal, which indicate that these lesions may have a common genetic mechanism of development. Further studies are necessary to better elucidate the molecular mechanisms involved in the pathogenesis of such lesions.