Oral leiomyomatous hamartoma: presentation of 3 cases and review of the literature.

Oral leiomyomatous hamartoma (OLH) is a rare lesion, with only 40 cases reported in the literature. It typically presents early in life as a nodule on the anterior maxillary alveolar tissues or the tongue. Its growth potential is limited, with few cases reaching dimensions >2.0 cm, and its microscopic composition includes an intact surface mucosa with an underlying fibrovascular stroma possessing an unencapsulated proliferation of smooth muscle fascicles. Excision is considered the definitive treatment. Here we describe the clinical, microscopic, histochemical, and immunohistochemical features and management of 3 cases of OLH and review the literature. The findings we present here can assist in performing differential diagnosis, particularly in discriminating between OLH and similar yet non-hamartomatous processes and in selecting appropriate management.

USP6 Gene Rearrangement by FISH Analysis in Cranial Fasciitis: A Report of Three Cases.

Cranial fasciitis (CF) is an uncommon benign myofibroblastic proliferation involving the soft and hard tissues of the cranium. It typically occurs in the pediatric population with a male predilection (male-to-female ratio 1.5:1). The clinical presentation is usually a rapidly expanding, painless nodule. Bone erosion may be appreciated radiographically. Histopathologic sections of CF show plump, fibroblast-like cells with pale, oval shaped nuclei and prominent nucleoli in a fibrous or myxoid background. Growth is self-limited and surgical excision is considered curative. Due to these features, CF is thought to be a variant of nodular fasciitis (NF). As with NF, CF may mimic a sarcomatous process and pose a diagnostic challenge to clinicians and pathologists alike. Erickson-Johnson et al. identified rearrangements of the ubiquitin-specific protease 6 (USP6) gene in 44 of 48 cases of NF. MYH9 was the fusion partner in 12 of these cases. To date, the molecular profile of CF has not been studied. Here we present the molecular findings in three cases of CF identified at our institution. Each case was subjected to fluorescence in-situ hybridization with appropriate negative controls. Two of three cases were positive for the USP6 gene rearrangement. The third case failed to hybridize, likely related to nucleic acid damage secondary to decalcification. Negative controls did not demonstrate the genetic rearrangement. These findings warrant further investigation of the USP6 gene rearrangement in CF, as it may prove helpful as a diagnostic adjunct in challenging cases.

A subset of ectomesenchymal chondromyxoid tumours of the tongue show EWSR1 rearrangements and are genetically linked to soft tissue myoepithelial neoplasms: a study of 11 cases.

AIMS: Ectomesenchymal chondromyxoid tumour (ECT) is a rare, benign intraoral neoplasm showing a predilection for the anterior dorsum of the tongue. The World Health Organization includes ECT in the pathological spectrum of soft tissue myoepithelioma. EWS RNA-binding protein 1 gene (EWSR1) rearrangement is found in 45% of cutaneous, soft tissue and bone myoepithelial neoplasms, and pleomorphic adenoma gene 1 (PLAG1) aberrations are found in 37% of EWSR1-negative soft tissue myoepitheliomas. The aim of this study was to evaluate the presence of EWSR1 and PLAG1 rearrangements in ECTs. METHODS AND RESULTS: Eleven formalin-fixed, paraffin-embedded ECTs were evaluated with fluorescence in-situ hybridization probes for EWSR1 (22q12) and PLAG1 (8q12). Among the 11 ECTs tested, three (27.3%) showed EWSR1 rearrangement in >15% of tumour cells, whereas eight (72.7%) cases did not show EWSR1 rearrangement. Eight of nine (89%) ECTs showed gain of EWSR1, probably representing gain of all or part of chromosome 22, in a varying proportion of neoplastic cells ranging between 1.4% and 27.9%. PLAG1 rearrangement was not detected in the successfully hybridized tissue sections (7/11). No correlation was observed between the molecular and histopathological findings, such as morphology of the neoplastic cells, the presence of atypia, and matrical type. CONCLUSIONS: We identified EWSR1 rearrangement in >25% of ECTs. These results suggest that some ECTs are at least genetically related to myoepithelioma of the soft parts. Finally, PLAG1 aberrations do not appear to be critical in the pathogenesis of ECT of the tongue.

Congenital granular cell lesion of the tongue: a report of two cases and review of the literature.

The congenital granular cell lesion most commonly occurs on the maxillary or mandibular alveolus of neonates. Extra-alveolar congenital granular cell lesion is exceptionally rare, with only 10 cases reported. Two additional cases occurring on the tongue are presented with a description of the clinical, histopathologic, and immunohistochemical features. The differential diagnosis is discussed, and the literature reviewed.

Giant Cell Tumor of the Larynx Treated by Surgery and Adjuvant Denosumab: Case Report and Review of the Literature.

Giant cell tumor of the larynx (GCTL) is a rare entity; only 34 cases have been reported in the literature. We report a case of GCTL in a 46 year-old male presenting clinical, radiographic, histological and therapeutic features. Previously reported cases are also reviewed.

EWSR1 and ATF1 rearrangements in clear cell odontogenic carcinoma: presentation of a case.

Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic tumor of the jaws that is more common in the mandible than maxilla and has a female preponderance with a peak incidence in the sixth decade. It is characterized by locally aggressive behavior and has the potential to metastasize. This tumor was recently reported to have a rearrangement of the Ewing sarcoma breakpoint region 1 gene (EWS RNA-binding protein 1, EWSR1) in 5 of 8 cases tested and of the activating transcription factor 1 gene (ATF1) in 1 case tested. We report a case of CCOC in the premolar area of the mandible in a 59-year-old woman. This case demonstrated the presence of both EWSR1 and ATF1 gene rearrangements by fluorescence in situ hybridization.