Odontogenic myxofibroma with HMGA2 overexpression and HMGA2 rearrangement

Odontogenic myxofibromas are variants of odontogenic myxomas that contain considerable amounts of collagen fibers in the myxoid stroma. Cytogenetic studies of odontogenic myxomas/myxofibromas have rarely been reported. This report describes the first case of an odontogenic myxofibroma presenting with HMGA2 protein overexpression and HMGA2 rearrangement in a 40-year-old woman. A 2.7-cm tumor in the premolar region of the right mandible was curettaged. There was no evidence of recurrence or metastasis at 12 months after the surgery. Histological examination revealed that the tumor comprised spindle or stellate cells with mild nuclear pleomorphism, abundant myxoid matrix and partly dense collagen fibers. Mitotic figures were rarely observed. Immunohistochemically, the tumor cells were diffusely positive for vimentin and HMGA2. Less than 1% of the tumor cells were positive for Ki-67. We detected split signals by interphase fluorescence in situ hybridization (FISH) in paraffin sections using HMGA2 break-apart probes. The breaks were certainly located within or near the HMGA2 gene. No rearrangement of the FUS gene was detected by FISH, implying discrimination from low-grade fibromyxoid sarcoma. It is suggested that HMGA2 rearrangement and HMGA2 protein overexpression may be associated with the tumorigenesis of odontogenic myxomas/myxofibromas, similar to the case for many other benign mesenchymal tumors.     

Odontogenic ghost cell tumor: A case report with cytologic findings

Odontogenic ghost cell tumor is a rare, neoplastic form of calcifying odontogenic cyst (Gorlin cyst) whose cytologic features have not been previously reported. We present a case of odontogenic ghost cell tumor diagnosed by fine-needle aspiration biopsy (FNAB). The aspirate was characterized by (1) tissue fragments with basaloid epithelial cells, (2) “ghost” cells, (3) scattered multinucleated giant cells, (4) rare, eosinophilic, densely hyalinized “dentinoid” material in close association with the basaloid cells, and (5) calcific debris. The aspirate was diagnosed as “consistent with odontogenic ghost cell tumor.” The cytologic features of odontogenic ghost cell tumor, as described, closely parallel the major histologic findings in this rare tumor. The differential diagnoses include other odontogenic tumors, squamous cell carcinoma, basaloid cell tumors of the salivary gland, and pilomatrixoma. Diagn. Cytopathol. 1998;18:199–203. © 1998 Wiley-Liss, Inc.     

Clear cell odontogenic tumor in the mandible: Report of a case with an immunohistochemical study of epithelial cell markers

A ram case of clear cell dontogenic tumor Is presented with an immunohistochemical study using epithelial cell markem. A 35-year-old Japanese man was admitted with a complaint of painless swelling In the anterior region of his mandible. Radiological examination showed a relatively well-defined multilocular radloiucency with root resorption of the adjacent teeth. Despite a subtotal mandlbulectomy, the tumor recurred thm times. Histologically, the tumor was composed of proiiferating clear cells and Infiltrated through the cancellous bone. Histochemical and ultrastruc-tural analyses detected cytoplasmic glycogen granules in the clear cells. They showed immunoreaetivities for cytokeratin 8,13 and 19, fllaggrin and anti-ameloblastoma antibodb, suggesting an odontogenic epithelial origin.     

Clear cell odontogenic carcinoma of the maxilla

Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic tumor associated with aggressive clinical behavior, metastasis and low survival. We report a case of CCOC affecting the maxilla of 62 year-old woman. It was first described as a clinicopathological entity in 1985 and to date only 67 cases were described in the English literature. We are understanding of the behavior of this carcinomas was depend on limited case reports. For these reason we found important to report this case of CCOC in the maxilla.     

Central mucoepidermoid carcinoma arising from glandular odontogenic cyst confirmed by analysis of MAML2 rearrangement: A case report

Central mucoepidermoid carcinoma (MEC) poses a diagnostic challenge because of its rarity and histological overlap with glandular odontogenic cyst (GOC). In MEC of both salivary glands and jaws, MAML2 arrangement has been well known as the specific gene alteration. We report a case of central MEC arising from GOC diagnosed by MAML2 fusion gene. A 57‐year‐old male presented a multilocular cystic lesion in left molar region of the mandible. Histopathologically, multiple cysts lined by thin cuboidal or non‐keratinized squamous epithelium with small duct‐like structures, mucous cells and ciliated cells were present. It was diagnosed as GOC. The recurrent lesion after nine years showed the proliferation of many cystic and solid nests composed of epidermoid, mucous and intermediated cells. Nested PCR revealed CRTC3‐MAML2 fusion gene in the recurrent lesion, but not in the primary one. Similarly, MAML‐2 rearrangement by FISH analysis was positive in the recurrent lesion, while negative for the primary one, thus confirming the diagnosis of central MEC arising from GOC. Analysis of MAML2 rearrangement can be used as a supportive evidence to distinguish central MEC from GOC.     

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 β‐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.     

Tigroid background in cytology of hyalinizing clear cell carcinoma of the salivary gland

Hyalinizing clear cell carcinoma (HCCC) is a rare and low grade salivary gland carcinoma with a unique recurrent EWSR1 gene translocation. HCCC most commonly arises from intraoral minor salivary glands and its cytological features have not been well evaluated. We report a 28‐year‐old man with palatal HCCC and emphasize the “tigroid background” and metachromatic matrix observed in scrape cytology. This “tigroid background,” usually associated with glycogen‐rich clear cell tumors, is an important cytological feature of HCCC. Awareness of this feature can do great help in pathological research and diagnosis. Diagn. Cytopathol. 2016;44:338–341. © 2015 Wiley Periodicals, Inc.     

Secondary EWSR1 gene abnormalities in SMARCB1‐deficient tumors with 22q11‐12 regional deletions: Potential pitfalls in interpreting EWSR1 FISH results

SMARCB1 inactivation occurs in a variety of tumors, being caused by various genetic mechanisms. Since SMARCB1 and EWSR1 genes are located close to each other on chromosome 22, larger SMARCB1 deletions may encompass the EWSR1 locus. Herein, we report four cases with SMARCB1‐deletions showing concurrent EWSR1 gene abnormalities by FISH, which lead initially to misinterpretations as EWSR1‐rearranged tumors. Our study group included various morphologies: a poorly differentiated chordoma, an extrarenal rhabdoid tumor, a myoepithelial carcinoma, and a proximal‐type epithelioid sarcoma. All cases showed loss of SMARCB1 (INI1) by immunohistochemistry (IHC) and displayed characteristic histologic features for the diagnoses. The SMARCB1 FISH revealed homozygous or heterozygous deletions in three and one case, respectively. The co‐hybridized EWSR1 probes demonstrated either unbalanced split signals or heterozygous deletion in two cases each. The former suggested bona fide rearrangement, while the latter resembled an unbalanced translocation. However, all the FISH patterns were quite complex and distinct from the simple and uniform split signals seen in typical EWSR1 rearrangements. We conclude that in the context of 22q11‐12 regional alterations present in SMARCB1‐deleted tumors, simultaneous EWSR1 involvement may be misinterpreted as equivalent to EWSR1 rearrangement. A detailed clinicopathologic correlation and supplementing the EWSR1 FISH assay with complementary methodology is mandatory for correct diagnosis. © 2016 Wiley Periodicals, Inc.     

Clear-cell odontogenic carcinoma with pulmonary metastases resembling pulmonary meningothelial-like nodules

Clear-cell odontogenic carcinoma (CCOC) is a rare neoplasm with malignant potential and unknown cytogenetic alterations. We describe the case of a 43-year-old woman who presented with an unusual odontogenic epithelial tumor. Histologically, the tumor was composed of clear-cell areas and exhibited a squamous pattern with little nuclear pleomorphism similar to benign squamous odontogenic tumor. Multiple small pulmonary nodules occurring 3 years after primary surgical treatment histologically closely resembled benign minute pulmonary meningothelial-like nodules (MPMN) with clear-cell features. Comparative genomic hybridization (CGH) and immunohistochemistry, performed as diagnostic adjuncts, revealed in the odontogenic tumor and the pulmonary lesions a very similar pattern of chromosomal aberrations (loss of 9, gains of 14q, 19 and 20 in both, and additional loss of 6 in the odontogenic tumor) and the same pattern of expression (positive for cytokeratin 5, 6, 8, 19 and negative for cytokeratin 18, epithelial membrane antigen, and vimentin), differing from that of MPMN. These findings confirmed the final diagnosis of metastasizing CCOC with partial squamous differentiation, substantiated the unfavorable prognosis of the clear-cell component, and highlighted the diagnostic impact of CGH and immunohistochemistry for classification of these morphologically peculiar pulmonary CCOC metastases.     

Identification of a novel fusion transcript EWSR1-VEZF1 by anchored multiplex PCR in malignant peripheral nerve sheath tumor

The aim of the study is to describe a novel genetic finding examining the molecular and pathological features of a case of malignant peripheral nerve sheath tumor occurring in the thigh of a 17-year-old male. Fusion gene detection using a next-generation sequencing-based anchored multiplex PCR technique (Archer FusionPlex Sarcoma Panel) was used to identify the novel fusion of EWSR1-VEZF1 from the frozen tumor sample. EWSR1-VEZF1 fusion is a novel molecular gene rearrangement involving exon 8 of the EWSR1 gene and exon 2 of the VEZF1 gene. Data were validated with gene sequencing and fluorescent in situ hybridization (FISH) analysis. This case report describes a novel rearrangement involving EWSR1 on chromosome 22 and VEZF1 on chromosome 17. The result obtained demonstrates the value of the next-generation sequencing-based anchored multiplex PCR technique (Archer FusionPlex Sarcoma Panel) both in diagnosis and patient care and might become a helpful diagnostic tool for this tumor type.     

Fine‐needle aspiration of soft tissue myoepithelioma

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. We describe the cytologic features of a soft tissue myoepithelioma arising in the right lower chest wall in a 65‐year‐old woman. The fine‐needle aspiration (FNA) smears showed round to oval, spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm, and resembled lobular carcinoma of breast. Ultrasound guided core biopsy showed the tumor cells had bland cytologic features, arranged in small cords, nests, and dissociated single cells, with no glandular differentiation or breast tissue seen. The tumor cells demonstrated immunoreactivity for cytokeratin (AE1/AE3) and glial fibrillary acidic protein, but were negative for estrogen receptor. Fluorescence in situ hybridization demonstrated the EWSR1 rearrangement, confirming the diagnosis of myoepithelioma. Diagn. Cytopathol. 2016;44:152–155. © 2015 Wiley Periodicals, Inc.     

牙源性钙化囊性瘤临床病理研究

目的探讨牙源性钙化囊性瘤(calcifying cystic odontogenic tumor,CCOT)的临床病理分型对治疗预后的影响。方法对39例CCOT的临床表现、X线影象、病理特征及治疗随访资料等进行回顾性分析。结果 39例中男性26例,女性13例,平均年龄29.6岁;病变位于下颌骨21例,上颌骨18例;临床多以颜面部肿胀就诊。X线主要表现为颌骨内界限清楚的放射透光区,单房或多房,其中伴有钙化斑点或团块。镜下均可见到特征性的影细胞,可分为4种类型:单纯囊肿型(17例)、CCOT伴牙瘤型(12例)、CCOT伴成釉细胞瘤增生型(7例)、CCOT伴其他良性牙源性肿瘤型(3例:伴成釉细胞纤维瘤2例,伴成釉细胞纤维牙瘤1例)。治疗均采用囊肿摘除术或刮治术,获得随访33例,复发6例,其中3例复发者均为CCOT伴成釉细胞瘤增生型且有囊壁内浸润(1例复发为牙源性影细胞瘤,1例20年后复发恶变为牙源性影细胞癌)。结论 CCOT伴成釉细胞瘤增生且有囊壁内浸润型行单纯囊肿摘除术或刮治术容易复发,可形成牙源性影细胞瘤或恶变成牙源性影细胞癌,此型肿瘤的手术范围应适当扩大并进行长期随访。     

Hyalinizing clear cell carcinoma of the parotid gland: Report of a recurrent case with aggressive cytomorphology and behavior diagnosed on fine‐needle cytology sample

A case of recurrent hyalinizing clear cell carcinoma (HCCC) of the parotid gland in a 46‐year‐old female is here introduced. The patient had undergone a left superficial parotidectomy 6 months ago in another institution for an alleged benign, circumscribed mass 2.4 cm in diameter of the left parotid gland. Histopathological examination revealed a poorly differentiated HCCC bearing a EWSR‐1 translocation on FISH examination. Fine Needle Cytology (FNC) was performed on three separate soft tissue masses in the pre‐masseterine area and a cytological diagnosis of recurrent, poorly differentiated, possibly aggressive variant of HCCC, was rendered. FISH performed on a destained Diff Quik stained smear demonstrated an ESWR‐1 translocation, which supported the cytopathological diagnosis. The cytomorphologic features and the differential diagnosis of this aggressive variant of HCCC are briefly discussed. Diagn. Cytopathol. 2014;42:63–68. © 2013 Wiley Periodicals, Inc.