Carcinomas with clear cell features and EWSR1 rearrangements: a report of 3 cases.

Salivary gland and odontogenic neoplasms with extensive clear cell change are rare lesions but have been increasingly characterized over the past decade. Among this heterogeneous group of neoplasms, hyalinizing clear cell carcinoma (HCCC), clear cell odontogenic carcinoma (CCOC), and clear cell myoepithelial carcinoma (CCMC) share a monophasic clear cell morphology and an EWSR1 gene rearrangement. While HCCC is relatively well characterized, there are a limited number of EWSR1-reaarranged CCMC of salivary glands reported, and its clinicopathologic features in relation to HCCC and nonclear cell myoepithelial carcinoma (MC) have not been clarified. This report describes the clinical, morphologic, and immunophenotypic features of 3 carcinomas composed predominantly of clear cells and with EWSR1 rearrangements by fluorescence in situ hybridization. A comparative literature analysis suggests that HCCC, CCMC, and nonclear cell MC of salivary glands are clinically, histopathologically, and molecularly distinct.

A retrospective clinico-pathologic analysis of cemento-osseous dysplasia in a South African patient population.

BACKGROUND: Cemento-osseous dysplasia (COD) is a fibro-osseous jaw bone lesion. The affected bone in COD progressively becomes sclerotic, poorly vascularized and susceptible to secondary osteomyelitis. OBJECTIVE: To provide a clinico-pathologic appraisal of COD in a South African patient population. METHODS: Archived records of 133 patients diagnosed with COD were reviewed for patient demographics, COD location, COD type, osteomyelitis or simple bone cyst secondary to COD. RESULTS: The mean age was 53.4 ± 13.5 years with a 94.7% female predilection. COD mainly affected the mandible (57.1%), followed by involvement of both jaws (38.3%) and maxilla (4.5%). Florid COD was the most prevalent (69.9%), followed by focal COD (18%) and periapical COD (12%). Florid COD showed a clear trend of increasing with age, peaking in the sixth decade and decreasing thereafter. Osteomyelitis and simple bone cyst presented as complications of COD in 74.4% and 5.3% of cases respectively, while 21.8% of all cases of jaw osteomyelitis during the study period were secondary to COD. CONCLUSION: A higher frequency of jaw osteomyelitis secondary to COD was found compared to previous studies. No significant association was shown between any of the COD types and secondary osteomyelitis.

Keratinizing odontogenic cysts with a spectrum of verrucoid morphology: investigation of a potential role of human papillomavirus.

OBJECTIVE: The role of human papillomavirus (HPV) in keratinizing odontogenic cysts (OC) has only rarely been studied. We describe the clinicopathologic findings in a series of OCs that had unusual keratinization patterns and were investigated for a possible HPV etiology. STUDY DESIGN: Tissue samples from 29 patients with keratinizing OCs were studied for light microscopic features suggestive of HPV infection and by an HPV DNA polymerase chain reaction assay. RESULTS: The mean age at presentation was 31.1 years; 79.3% of the OCs occurred in the mandible and 46.4% were associated with an impacted tooth. The phenotypic characteristics koilocytes, hypergranulosis, and a verrucous pattern of the cyst-lining epithelium were observed in 69%, 62.1%, and 17.2% of cases, respectively. These histomorphologic features did not, however, correlate with HPV infection. CONCLUSIONS: HPV does not appear to play a role in keratinizing OCs and is not responsible for the wart-like histomorphologic features that may be seen in these lesions.

Ossifying Fibroma in a Patient With Oculocerebrocutaneous (Delleman) Syndrome.

Delleman syndrome is a rare neurocutaneous disorder characterized by congenital anomalies affecting the eye, skin, and central nervous system. This disorder was first raised as a distinct syndromic entity by Delleman and Oorthuys in 1981 under the term "oculocerebrocutaneous syndrome" (OCCS). Since then, fewer than 40 cases have been reported. All cases have been sporadic, and no patient with an abnormal karyotype has been reported. Although the etiology is still unknown, several theories have been advanced. Most of the tissues affected by OCCS are neural crest derivatives, with a striking homogeneity of the tissues and regions involved. It is this recurring craniofacial pattern of OCCS that lends support to the hypothesis that the most probable pathogenesis is a neurocristopathy that interferes with craniofacial morphogenesis. Ossifying fibroma is a destructive, potentially deforming, benign tumor that can occur almost anywhere in the facial skeletion. Some cases of ossifying fibroma have occurred in patientswith underlying neurocutaneous syndromes such as neurofibromatosis, Sturge-Weber syndrome, and encephalocraniocutaneous lipomatosis (ECCL). We report a patient with OCCS who presented with an ossifying fibroma. This has not been reported previously and is noteworthy in that it might be part of a wider phenotypic spectrum of the less common manifestations associated with OCCS.

Recent advances in mucin immunohistochemistry in salivary gland tumors and head and neck squamous cell carcinoma.

This review focuses on the immunohistochemical expression of members of the MUC-type mucin family in salivary gland tumors and head and neck squamous cell carcinomas (HNSCC). Information is available on changes in the expression levels and distribution profiles of MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6 and MUC7 in tumors of the salivary glands; and of MUC1, MUC2 and MUC4 in HNSCC. In salivary gland tumors the expression patterns of MUC2, MUC3, MUC5AC and MUC6 appear to be very closely correlated with the histopathological tumor type indicating their potential use to improve diagnostic accuracy in salivary gland neoplasia. Some MUC-type mucins have emerged as valuable prognostic indicators in pleomorphic adenoma, mucoepidermoid carcinoma and HNSCC. Nine antibodies directed against different MUC1 antigens have thus far been examined in HNSCC of which monoclonal antibodies DF3, HMFG-1 and Ma695 have shown significant correlations with disease outcome. The importance of taking the specific anti-MUC antibody into consideration when comparing the results of different studies on MUC expression in salivary gland tumors and HNSCC is also highlighted in this review.

Neuroendocrine cells and associated malignancies of the oral mucosa: a review.

Neuroendocrine cells of the oral mucosa constitute an under-recognized component of the diffuse neuroendocrine system with diverse subpopulations and elusive biologic roles in the oral cavity. Primary malignant oral tumors that show a neuroendocrine phenotype display histomorphologic heterogeneity thereby giving rise to a spectrum of lesions in this rare category of oral malignancy. These lesions can be divided into neuroendocrine carcinomas (NECs) of small cell or non-small cell type. The former is further subdivided into the Merkel cell type or the pulmonary type while the latter includes atypical carcinoid tumor and large cell NEC. All histologic subtypes of oral NEC appear to have a strong predilection for men in their fifth or sixth decade and arise predominantly in the non-keratinized oral mucosa. The biologic behavior of oral Merkel cell carcinomas appears to be more aggressive than those of skin. It remains to be determined whether histologic categorization of the remaining tumor subtypes is predictive of patient survival in oral neuroendocrine tumors.

Central adenoid cystic carcinoma of the mandible with odontogenic features: Report of a case.

BACKGROUND: Primary intraosseous salivary-type adenocarcinomas are rare neoplasms of uncertain histogenesis. The prevailing theories suggest origin from heterotopic salivary glands, odontogenic rests, or cystic epithelium. METHODS: A case of central adenoid cystic carcinoma is reported in a 53-year-old woman who presented with a painless swelling in the anterior segment of her lower jaw. Radiographic examination confirmed the presence of an expansile, radiolucent lesion within the mandible with a multilocular appearance. On light microscopy analysis, areas showing cribriform and tubular growth patterns; admixed cysts, some of which were characterized by the presence of localized plaque-like thickenings of their epithelial linings; and the formation of aberrant dental hard tissue were observed. RESULTS: The radiographic and histomorphologic findings highlight the potential misdiagnosis of this rare tumor. The findings also draw attention to an embryologic histogenetic concept for some central salivary neoplasms. CONCLUSION: The divergent salivary and odontogenic differentiation evident in this tumor signifies the pluripotential nature of derivatives of oral ectoderm.

A rare case of lymphoepithelial carcinoma of the lip.

Lymphoepithelial carcinoma (LEC) is a rare category of malignant neoplasms that share morphologic features with undifferentiated nasopharyngeal carcinoma, which can be regarded as the prototype Epstein-Barr virus (EBV)-positive epithelial neoplasm. A similar association with EBV is emerging for LEC of the oral cavity, which appears to be strongly influenced by the ethnic origin of the patient. A rare case of primary LEC of the lower lip in a 73-year-old Caucasian man is described. The tumor showed a striking microscopic resemblance to undifferentiated nasopharyngeal carcinoma (lymphoepithelioma) with features of a syncytial growth pattern, large undifferentiated tumor cells with vesicular nuclei, prominent eosinophilic nucleoli, and a dense intratumoral lymphocytic infiltrate. There was, however, no evidence of EBV infection of the tumor cells by immunohistochemistry and polymerase chain reaction, suggesting that EBV probably does not play a role in the pathogenesis of LEC of the lip in Caucasian patients.

Adenomatoid odontogenic tumor (AOT) originating in a unicystic ameloblastoma: a case report.

The follicular variant of the adenomatoid odontogenic tumor (AOT) is thought to originate from the reduced enamel epithelium of the dental follicle. The origin of the extra-follicular variant however, remains less clear. This paper presents a case of an extra-follicular AOT, which we believe originated from the epithelial lining of a unicystic ameloblastoma, and reviews the literature. The available evidence seems to indicate that some extra-follicular AOTs might arise as secondary phenomena within pre-existing odontogenic cysts or cystic tumors.