Immunohistochemical correlates of recurrent genetic alterations in sarcomas

Accurate diagnosis of sarcomas relies on the integration of clinical, histopathological and molecular features. Our understanding of the latter has increased dramatically in recent years with the application of high‐throughput sequencing. Concomitantly, the role of immunohistochemistry has expanded as genomic alterations have been exploited by the development of diagnostic markers that serve as surrogates for their detection. Herein, we review selected immunohistochemical markers that can infer the presence of diverse molecular events. These include gene fusions in vascular neoplasms (FOSB, CAMTA1 and TFE3), round cell sarcomas (BCOR, DUX4 and WT1), and fibroblastic/myofibroblastic tumors (STAT6, ALK and Pan‐TRK); amplifications in well‐differentiated and dedifferentiated liposarcomas (MDM2 and CDK4); and deletions in several aggressive neoplasms (SMARCB1 and SMARCA4). Protein correlates of single nucleotide variants (beta‐catenin in desmoid fibromatosis) and epigenetic alterations (histone H3K27me3 in malignant peripheral nerve sheath tumor) and markers discovered through gene expression profiling (NKX2.2 and MUC4) are also discussed.     

The management of parotid tumors

The majority of salivary gland tumors are of epithelial origin. Parotid gland is the most common location of the tumors. Surgery is the main modality for the management of parotid tumors. Radiotherapy, chemotherapy etc are the auxiliary modalities.     

Recurrent ameloblastoma in the anterior skull base： Report of 3 cases

Ameloblastoma is a benign but locally invasiveepithelial odontogenic tumor. Recurrence ofameloblastoma is most common after inadequate treat-ment, with an incidence up to 90% in the mandibleand 100% in the maxilla[1]. Despite radical resectionsincluding adjacent soft tissues, a recurrence rate of5% to 15% has been reported[2]. However, only a fewcases of recurrence reported in the literature involvedthe temporal fossa [3～5]. We presented 3 patients withrecurrent ameloblastoma in the anterior …     

Mandibular metastasis of angiosarcoma. A case report

A case of mandibular metastasis of angiosarcoma is described, along with its clinical manifestations and histopathological features. This is the 5th case ever reported of metastasis of angiosarcoma to the mandible.     

Evidence for an inhibitor of osteoclast attachment in dentinal matrix

Abstract The ability of osteoclasts to colonize in vitro different preparations of dentin extracted with guanidinium hydrochloride (GuHCl) was studied in order to establish morphological evidence for an extractable inhibitor of osteoclast spreading within dentin. Osteoclasts were isolated from neonatal rats and seeded onto pieces of fully mineralized dentin, demineralized dentin and predentin extracted with GuHCl. Osteoclasts were also seeded onto unextracted tissues. The results were evaluated with scanning electron microscopy. Osteoclasts colonized and resorbed fully mineralized dentin, whereas clastic cells were not observed on unextracted demineralized dentin and predentin. In contrast to this, osteoclasts attached and spread on demineralized dentin and predentin extracted with GuHCl. It was concluded that the non-collagenous organic component of dentin contains an extractable inhibitor of osteoclastic attachment and spreading. It is tempting to speculate that the inhibitor may be responsible for the naturally occuring resistance of dentin to resorption.     

Juvenile ossifying fibroma. An analysis of 33 cases with emphasis on histopathological aspects

Juvenile ossifying fibroma (JOF) is a maxillofacial fibro-osseous lesion that may show cell-rich osteoid strands or psammoma-like ossicles. Whether both types are variants of a single entity or different lesions under the same diagnostic label is a subject of debate. This problem was investigated by analyzing a series of 33 patients with lesions having one or both of the above histological appearances. It was concluded that osteoid strands define a unique fibro-osseous lesion but that lesions with psammoma-like ossicles fall within the morphological spectrum of cemento-ossifying fibroma. Therefore the term juvenile ossifying fibroma should be reserved for the lesion with the osteoid strands.     

钌红电镜组织化学技术应用

目的 采用钌红电镜组织化学技术对涎腺多形性腺瘤，肌上皮瘤，腺样囊性癌和基底细胞瘤进行研究以示踪肿瘤中蛋白多糖的形成和分布。方法 新鲜标本分切后固定于2.5%戊二醛中24小时，其中含0.2%的钌红；0.1M二甲肿酸钠缓冲液冲洗过夜；1%OsO4后固定1小时；丙酮逐级脱水，Epon812包埋，在半薄切片上定位，超薄切片用Opton109型电镜观察，结果 在多形性腺瘤和肌上皮瘤中，粘液样区域内充满了蛋白多糖，这种蛋白多糖是由NMCs分泌产生的，腺样囊性癌的NMCs也分泌产生蛋白多糖，该瘤中筛状结构形成是由于NMCs分泌蛋白多糖所致，这种分泌功能的出现是肌上皮细胞向肿瘤性细胞转变的一个标志。结论 钌红电镜组织化学技术方法可检涎腺肿瘤中蛋白多糖形成和分布，是一种简便，易行的方法。     

Oral focal mucinosis

Oral focal mucinosis (OFM) is an uncommon clinicopathological entity which is considered to be the oral counterpart of cutaneous focal mucinosis and/or cutaneous myxoid cyst. It is comprised of a clinically elevated mass with a histological picture of localized areas of myxomatous connective tissue. The present study adds 15 new cases of OFM to the literature and analyzes their clinical, histological and histochemical features. Most of the lesions were located in the gingiva and alveolar mucosa. The nature of the lesion is unclear and it is suggested that the mucinous accumulation is the result of fibroblastic overproduction of hyaluronic acid.     

Epidermal growth factor receptor in odontogenic cysts and tumors

The expression of epidermal growth factor receptor (EGFR) was investigated in 67 cases of odontogenic cysts and 35 cases of odontogenic tumors using monoclonal antibody to EGFR (Biomarker, Israel) to determine the presence and significance of this transmembrane growth factor receptor. The cystic epithelial cells of odontogenic cystic lesions (keratocyst 60%; primordial cyst 75%; radicular cyst 35%; and follicular cyst 47.4%) were positive to EGFR staining. Cytochemical characterization of EGFR in those cystic epithelium was cell membrane positive type as in the normal epithelium. No expression of EGFR was found in the odontogenic tumors. This diversity of EGFR represents no binding activity of EGF, or loss of EGFR in the tumor cell upon EGFR mediated growth in odontogenic tumors was suggested a different tumor cell growth factor status or microenvironment in cell proliferation mechanism at the cellular level in cysts and tumors of odontogenic origin.     

Infrequent clinicopathological findings in 108 ameloblastomas

One hundred and eight ameloblastomas diagnosed in a rural black Africa population were analysed for clinicopathologic findings other than those classically described. One patient had a polycystic ameloblastoma adjacent to an ameloblastic fibroma. Two other polycystic ameloblastomas showed aneurysmal bone cyst formation and one mandibular tumour was diagnosed as a keratoameloblastoma. Microscopic changes resembling an adenomatoid odontogenic tumour were present in association with two unicystic ameloblastomas and a HPV18-positive verrucous lesion occurred in the lining of a cystic space of a polycystic ameloblastoma. Two ameloblastomas contained eosinophilic granules in all tumor cells and melanocytes were diffusely present in another. One case exhibited a focus of mucous cell metaplasia. Two polycystic ameloblastomas showed diffuse interstitial ossification. One mandibular tumor was diagnosed as a desmoplastic ameloblastoma and another as an odontoameloblastoma. This study demonstrated that although ameloblastomas are regarded as a fairly homogeneous group of neoplasms, detailed investigations prove clinicopathologic diversity in a significant number of lesions.