hSNF5/INI1-deficient tumours and rhabdoid tumours are convergent but not fully overlapping entities

Rhabdoid tumours (RTs) are rare but highly aggressive tumours of childhood. Their rarity and their miscellaneous locations make the diagnosis particularly challenging for pathologists. Central nervous system and peripheral RTs have been associated with biallelic inactivation of the hSNF5/INI1/SMARCB1 (hSNF5/INI1) tumour suppressor gene. Immunohistochemistry (IHC) with a monoclonal anti-hSNF5/INI1 antibody has recently been proposed as an efficient diagnostic tool for RTs. We have conducted a retrospective study of 55 tumours referred to our institution with a suspicion of RT. This analysis included pathological review, IHC with anti-hSNF5/INI1 antibody, and molecular investigation using quantitative DNA fluorescent analysis and sequencing of the nine exons of hSNF5/INI1. The molecular lesion could be detected in 37 of the 39 cases exhibiting negative staining for hSNF5/INI1. In the two discrepant cases, the lack of detection of genetic abnormality was probably owing to the presence of a high number of non-tumour cells in the samples. This indicates that hSNF5/INI1 IHC is very sensitive and highly specific for the detection of hSNF5/INI1 loss-of-function. Among the 38 cases with typical RT histological features, six failed to exhibit hSNF5/INI1 mutation and stained positive for hSNF5/INI1. This strongly supports the evidence of a second genetic locus, distinct from hSNF5/INI1, associated with RT. Conversely, seven tumours with histological features poorly compatible with RT stained negative for hSNF5/INI1; they nevertheless exhibited an age of onset and a clinical behaviour similar to RT. This suggests that hSNF5/INI1 inactivation is not strictly limited to typical RT but characterizes a wider family of hSNF5/INI1-deficient tumours. Consequently, we believe that anti-hSNF5/INI1 IHC should be performed widely, even when the pathological characteristics are not typical. The molecular investigation should be performed in infants when a rhabdoid predisposition syndrome is suspected.     

Increased expression of Gab2, a scaffolding adaptor of the tyrosine kinase signalling, in gastric carcinomas

AIMS: Mounting evidence indicates that alterations of protein kinase signalling pathways play crucial roles in the pathogenesis of cancers. Gab2 (Grb2-associated binding protein 2), a member of the family of Gab scaffolding adaptors, transmits and amplifies the signals from receptor tyrosine kinases. A recent study demonstrated that Gab protein was over-expressed in breast cancers, and the over-expressed Gab2 increased proliferation and invasion of the cells, indicating that Gab2 is an oncogenic protein. However, the roles of Gab in other cancers are largely unknown. METHODS: In this study, to see whether Gab2 expression could be a characteristic of gastric cancers, we analysed the expression of Gab2 in 60 gastric adenocarcinomas by immunohistochemistry using a tissue microarray. RESULTS: In the normal gastric mucosal epithelial cells, Gab2 protein was expressed in parietal and zymogen cells, but not in other mucosal epithelial cells. In the cancer cells, Gab2 expression was detected in 40 (67%) of the 60 gastric adenocarcinomas. The Gab2 expression was observed in 12 (60%) of the 20 early gastric carcinomas and 28 (70%) of the 40 advanced gastric carcinomas. There was no significant association of Gab2 expression with clinocopathological characteristics, including invasion, metastasis and stage. CONCLUSION: Our data indicate that Gab2 over-expression is a feature not only of breast cancers, but also of gastric cancers. Increased expression of Gab2 in malignant gastric cells compared with normal epithelial cells suggests that Gab2 expression may play a role in gastric cancer development.     

Immunohistochemistry as a diagnostic aid in cervical pathology

As with biopsies from other sites in the female genital tract, immunohistochemistry is now being increasingly used in cervical pathology as an aid to diagnosis. In this review, I discuss applications of immunohistochemistry in diagnostic cervical pathology with a particular focus on recent developments. It is emphasised that immunohistochemistry is to be used as an adjunct to routine morphological examination and that no marker is totally specific or sensitive for a given lesion. Although much of this review focuses on glandular lesions, the value of markers, such as MIB1 and p16, in the assessment of pre-invasive cervical squamous lesions is discussed. In the broad field of cervical glandular lesions, topics covered include: the value of markers such as MIB1, p16 and bcl-2 in distinguishing adenocarcinoma in situ and glandular dysplasia from benign mimics; markers of mesonephric lesions, including CD10; markers of value in the diagnosis of minimal deviation adenocarcinoma, such as HIK1083; markers of value in distinguishing metastatic cervical adenocarcinoma in the ovary from primary ovarian endometrioid or mucinous adenocarcinoma. Rarely ectopic prostatic tissue occurs in the cervix, which can be confirmed by positive staining with prostatic markers. A panel of markers, comprising oestrogen receptor, vimentin, monoclonal carcinoembryonic antigen and p16, is of value in distinguishing between a cervical adenocarcinoma and an endometrial adenocarcinoma of endometrioid type. Markers of use in the diagnosis of cervical neuroendocrine neoplasms, including small cell and large cell neuroendocrine carcinoma, are discussed. It is stressed that small cell neuroendocrine carcinomas may be negative with most of the commonly used neuroendocrine markers and this does not preclude the diagnosis. p63, a useful marker of squamous neoplasms within the cervix, is of value in distinguishing small cell neuroendocrine carcinoma (p63 negative) from small cell squamous carcinoma (p63 positive) and in confirming that a poorly differentiated carcinoma is squamous in type.     

Active caspase 3 and DNA fragmentation as markers for apoptotic cell death in primary and metastatic liver tumours

AIMS: The induction of tumour cell death by apoptosis is a major goal of cancer therapy and the in situ detection of apoptosis in tumour tissue has become an important diagnostic parameter. Different apoptosis detection methods assess distinct biochemical processes in the dying cell. Thus, their direct comparison is mandatory to evaluate their diagnostic value. The aim of this study was to compare the immunohistochemical detection of active caspase 3 and single-stranded DNA in primary and metastatic liver tumours as markers of apoptotic cell death. METHODS: We studied detection of active caspase 3 and single-stranded DNA in 20 primary hepatocellular carcinomas (HCC) and 20 liver metastases from colorectal carcinomas (CRC) using immunohistochemistry on paraffin sections. RESULTS: Our results reveal that both methods are suitable and sensitive techniques for the in situ detection of apoptosis, however, they also demonstrate that immunohistochemistry for active caspase 3 and single-stranded DNA have differential sensitivities in HCC and CRC. CONCLUSION: The sensitivity of apoptosis detection using immunohistochemistry for active caspase 3 and single-stranded DNA may be tumour cell type dependent.     

Occult bone marrow involvement in patients with diffuse large B-cell lymphoma: results of a pilot study

AIMS: It is known that advanced stage disease in diffuse large B-cell lymphoma (DLBCL) confers a poor prognosis, and staging investigations are routinely performed at diagnosis, including a bone marrow (BM) biopsy. However, examination of the BM is usually limited to routine light microscopy, with the role of ancillary investigations remaining unestablished. The aim of this pilot study was to estimate the incidence of occult marrow involvement using flow cytometry, immunohistochemistry and immunoglobulin heavy chain (IgH) gene rearrangements, and to determine the impact on survival. METHODS: Clinical and pathological data were obtained on 36 patients diagnosed with DLBCL. Immunohistochemistry using CD3, CD45RO, CD20 and CD79a, and polymerase chain reaction (PCR) to look for IgH gene rearrangements were performed on formalin fixed BM trephines. RESULTS: Nine patients had morphologically apparent BM involvement. Occult marrow involvement was found in seven of 36 (19.4%) patients using the additional diagnostic modalities. When these cases were included with morphologically apparent cases in a proposed new definition of marrow involvement, the median survival of patients with BM involvement was statistically worse (p=0.02) than those without involvement. CONCLUSIONS: The results indicate that use of additional tests on BM at diagnosis can upstage disease for a proportion of patients, which appears to correlate adversely with survival.     

肝脏血管周上皮样细胞肿瘤的临床病理分析

目的 探讨肝脏血管周上皮样细胞肿瘤(PEComa)的临床病理学特征、诊断、鉴别诊断及预后.方法 报道2例发生于肝脏的PEComa,对2例少见部位PEComa行HE、免疫组化染色,并进行相关文献复习.结果 2例肝脏PEComa均发生于中年女性,45～53岁,临床均无特异性症状.CT分别显示肝右叶后下段和左顶叶部界限清楚的类圆形肿块,初诊考虑肝恶性肿瘤.镜下肿瘤主要由上皮样细胞和丰富血窦组成,1例无脂肪细胞成分,另1例伴多灶性脂肪细胞分化成分.免疫表型:肿瘤细胞均Melan-A、HMB45、SMA阳性.结论 发生于肝脏的PEComa临床较少见,组织起源仍然不清,临床需与原发性肝癌及转移性恶性黑色素瘤鉴别,大多生物学行为偏良性,诊断恶性需足够的证据支持和长期的随访观察.     

Endoscopic molecular imaging of early gastric cancer using fluorescently labeled human H-ferritin nanoparticle

Optical imaging technologies improve clinical diagnostic accuracy of early gastric cancer (EGC). However, there was a lack of imaging agents exhibiting molecular specificity for EGCs. Here, we employed the dye labeled human heavy-chain ferritin (HFn) as imaging nanoprobe, which recognizes tumor biomarker transferrin receptor 1 (TfR1), to enable specific EGC imaging using confocal laser endomicroscopy (CLE). TfR1 expression was initially examined in vitro in gastric tumor cells and in vivo through whole-body fluorescence and CLE imaging in tumor-bearing mice. Subsequently, dye labeled HFn was topically applied to resected human tissues for EGC detection. CLE analysis of TfR1-targeted fluorescence imaging allowed distinction of neoplastic from non-neoplastic tissues (P?<?0.0001), and TfR1 expression level was found to correlate with EGC differentiation degrees (P?<?0.0001). Notably, the CLE evaluation correlated well with the immunohistochemical findings (κ-coefficient: 0.8023). Our HFn-nanoprobe-based CLE increases the accuracy of EGC detection and enables visualization of tumor margins and endoscopic resection.     

In situ localization of gelatinolytic activity during development and resorption of Meckel's cartilage in mice

Degradation of Meckel's cartilage in the middle portion is accompanied by hypertrophy and death of chondrocytes, calcification of the cartilaginous matrix, and chondroclastic resorption. We hypothesize that the gelatinolytic activity of matrix metalloproteinases (MMPs) largely contributes to the degradation of extracellular matrix (ECM) in the process. The activity in Meckel's cartilage of mouse mandibular arches at embryonic days 14-16 (E14-E16) was examined by a combination of in situ zymography (ISZ), using quenched fluorescent dye-labeled gelatin as a substrate, with CTT (a selective inhibitor of MMP-2 and -9) or with EDTA (a general MMP inhibitor). On E14 and E15, ISZ showed fluorescence in the perichondrium, in the intercellular septa between chondrocytes, and in the nucleus of chondrocytes. CTT attenuated fluorescence, and EDTA eliminated it. On E16, calcified cartilaginous matrix showed intense fluorescence, and dot-like fluorescence was observed in as-yet uncalcified intercellular septa, even after CTT treatment. EDTA inhibited fluorescence, but unexpectedly intense fluorescence was found in the cytoplasm of hypertrophic chondrocytes facing the resorption front. MMP-2, -9, and -13 immunoreactivity was detected in the perichondrium and chondrocytes of Meckel's cartilage. These findings suggest that MMPs and other proteinases capable of degrading gelatin play an integral role in the development, calcification, and resorption of Meckel's cartilage through ECM reconstitution.     

Epithelioid hemangioendothelioma of the oral cavity

OBJECTIVE: To investigate the clinicopathological characteristics and biologic behaviour of epithelioid hemangioendothelioma in the oral cavity. MATERIALS AND METHODS: The clinical features and pathological findings of nine cases with intraoral epithelioid hemangioendothelioma were reviewed, including immunohistochemistry study. RESULTS: This series comprised seven males and two females aged 6-53 years (mean 28 years). The sites of the tumour included the tongue (n = 4), lip (n = 1), the gingiva and alveoli of the maxilla (n = 1), the gingiva and alveoli of the mandible (n = 1), buccal mucosa (n = 1), and the floor of the mouth (n = 1). A painless solitary mass was the most common presentation and was found in eight cases. On pathology, the tumour grew in short strands, cords or nests of polygonal to slightly spindled epithelioid cells in fibro-myxoid stroma, with formation of intracytoplasmic lumina. Tumour cells were immunoreactive to CD34, FVIIIRAg, and vimentin. Focal-positive cytokeration were observed in three cases. Immunoreactivity for S-100 protein, epithelial membrane antigen (EMA) and human herpesvirus (HHV)-8 was negative in all cases. Two cases recurred after surgical excision, but no patient developed local or distant metastasis. CONCLUSIONS: Wide local excision with long-term follow-up seems to be the treatment of choice for intraoral epithelioid hemangioendothelioma because of their unpredictable biological behaviour and recurrence potential.     

Altered E-cadherin/beta-catenin expression in oral squamous carcinoma with and without nodal metastasis

OBJECTIVES: The aim of this study was to investigate the potential use of E-cadherin, a tumour-suppressor gene product involved in establishing cell-cell adhesion and one of its associated proteins, beta-catenin, as markers of nodal metastasis in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Thirty invasive OSCCs in patients with (n = 19) and without (n = 11) nodal metastases, as confirmed on histopathologic examination of the resected regional lymph nodes (n = 30), were examined for E-cadherin and beta-catenin expression by immunohistochemistry. RESULTS: There was a highly significant association (P < 0.0001) between E-cadherin and beta-catenin expression and tumour differentiation by conventional Broders' grading of the whole tumour. Irrespective of the nodal status and invasive tumour front (ITF) grading score, however, loss of expression was recorded at the ITF in 28 (93%) of 30 tumours and 22 (73%) of 30 tumours stained for E-cadherin and beta-catenin respectively. CONCLUSION: The results of this study suggest an association between loss of expression of E-cadherin and beta-catenin and a lower degree of differentiation; however, their use as markers of nodal metastasis in OSCC appears unreliable.