Adult variant of atypical teratoid/rhabdoid tumor: Immunohistochemical and ultrastructural confirmation of a rare tumor in the sella tursica

Atypical teratoid/rhabdoid tumor (AT/RT) is a distinctive neoplasm of young children characterized by diverse histology and fatal course. Adult presentation is rare. We describe the diagnostic problems associated with an AT/RT arising in the sellar region in a 46-year-old female.     

A case of an atypical teratoid/rhabdoid tumor with distinctive histology in the pineal region in an adult patient

A 31-year-old man suffered from headaches and presented at a hospital after the symptom worsened. Obstructive hydrocephalus and a pineal tumor were identified, and he was transferred to our hospital for further investigation and treatment. Cranial computed tomography revealed a hypodense mass lesion on the right of the pineal region, and calcifications and enlargement of the lateral and third cerebral ventricles were also evident. Blood tests were negative for all tumor markers. Laparoscopic biopsy and third-ventricle fenestration were performed that day as an emergency surgery to treat the obstructive hydrocephalus. Postoperative cranial magnetic resonance imaging revealed a solid tumor that was hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, and heterogeneously enhanced by Gd. Subsequently, the tumor increased in size, and craniotomy and tumorectomy were performed. Histologically, the tumor proliferated as round or short spindle-shaped cells in a myxoid matrix, forming arrays that surrounded the blood vessels. As a few cells with eosinophilic cytoplasm were also present and immunostaining for INI-1 was negative, the patient was diagnosed with atypical teratoid/rhabdoid tumor (AT/RT). AT/RT of the pineal region in adults is rare, and herein, we report the morphological characteristics of this case and reviewed the relevant literature.     

Primary atypical teratoid/rhabdoid tumor of central nervous system in children: a clinicopathological analysis and review of literature in China

Atypical teratoid/rhabdoid tumor (AT/RT) is a very rare and highly malignant embryonal tumor in the central nervous system (CNS). Five patients (4 girls and 1 boy) with AT/RT were treated in our hospital. The clinical histories, symptoms, neuroimaging aspects, therapies, histological and immunohistochemical findings and follow-up information were reviewed. The patients ranged from 8 to 40 months with a mean age of 20.6 months. One tumor was located in the spinal cord, two in cerebellum and two in the pineal region. The imagings of the tumors resemble medulloblastomas. Pathological examinations showed that one patient had medulloblastoma differentiation, one had choroid plexus carcinoma differentiation, and one had mesenchymal components. Immunohistochemical staining showed that all of the tumors lost the nuclear expression of integrase interactor 1 (INI1), and were positive for Vimentin, S-100 protein and epithelial membrane antigen. One case with no recurrence after 24 months may have benefited from radical excision and postoperative radiotherapy. The other 4 patients died 8, 4, 1 and 1-month respectively after operation without radiotherapy. The diagnosis of AT/RT depends on full sampling, careful observation the morphological characteristics and INI1 examination, even when the tumor are presented in uncommon sites, such as the spinal cord and the pineal region.     

Claudin-6 is of limited sensitivity and specificity for the diagnosis of atypical teratoid/rhabdoid tumors

Recent gene expression microarray analyses have indicated that claudin-6 is specifically expressed in atypical teratoid rhabdoid tumors (AT/RTs), suggesting a role as a positive diagnostic marker in addition to SMARCB1 (INI1) loss, which is encountered in the majority of AT/RTs. In order to investigate the potential of claudin-6 as a diagnostic marker, expression was investigated in 59 AT/RTs and 60 other primary central nervous system (CNS) tumors, including primitive neuroectodermal tumors, medulloblastomas, choroid plexus tumors, and both pediatric and adult low- and high-grade gliomas using immunohistochemistry. Claudin-6 was expressed in 17/59 AT/RTs (29%), but also in a variety of other primary CNS tumors, including 60% of medulloblastomas and 21% of malignant gliomas. Even though high staining scores (2+ or 3+) were more often encountered in AT/RTs (Chi-square 4.177; P=0.041), the overall frequency of claudin-6 staining was not significantly higher in AT/RTs as compared with the other tumors (17/59 vs. 16/60; Chi-square=0.328; P=0.567). In a subgroup of 43 AT/RT patients, of which follow-up data were available, claudin-6 expression did not show any correlation with survival. In conclusion, claudin-6 immunohistochemistry is of limited sensitivity and specificity for the diagnosis of AT/RT and does not correlate with clinical behavior.     

Epidermal growth factor receptor gene amplification and protein overexpression in basal-like carcinoma of the breast

Shao M‐M, Zhang F, Meng G, Wang X‐X, Xu H, Yu X‐W, Chen L‐Y & Tse G M
(2011) Histopathology 59 , 264–273 Epidermal growth factor receptor gene amplification and protein overexpression in basal‐like carcinoma of the breast Aims: Epidermal growth factor receptor (EGFR) is frequently expressed in basal‐like breast cancer (BLBC). The aim of this study was to evaluate their correlation as detected by immunohistochemistry (IHC) or fluorescence in‐situ hybridization (FISH). Methods and results: IHC for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER) 2, cytokeratin (CK) 5/6 and EGFR, and FISH for EGFR amplification, were performed in 59 cases of BLBC. EGFR IHC results were scored semiquantitatively, and compared with its gene amplification status. ER, PR and HER2 were negative in all cases, whereas 35 and 55 cases were positive for CK5/6 and EGFR. For EGFR IHC, 20, 11, 11 and 17 cases showed a negative, a low, an intermediate or a high staining level, respectively, and seven cases showed gene amplification by FISH, with two, 19, 11 and 20 cases showing balanced monosony, disomy, trisomy, and polysomy respectively. Immunohistochemical expression in gene‐amplified tumours was significantly higher than in those without amplification, including balanced polysomy tumours. EGFR immunohistochemical expression also correlated with the EGFR/chromosome 7 ratio. High sensitivity (86%) and negative predictive value (98%) were achieved with high‐level immunohistochemical expression as a cut‐off to predict gene amplification. Conclusions: High‐level EGFR immunohistochemical expression correlated with and predicted EGFR amplification, and may be used as a screening method to exclude gene amplification.     

Epidermal growth factor receptor expression and gene copy number in fibrolamellar hepatocellular carcinoma

Increased expression of epidermal growth factor receptor (EGFR), a transmembrane tyrosine kinase, is associated with tumor progression in many carcinomas. Epidermal growth factor receptor inhibitors have shown promise in treating some of these tumors. Fibrolamellar hepatocellular carcinoma (FL-HCC) is an aggressive neoplasm that occurs in young patients with no history of cirrhosis. This study examines the expression and gene copy number of EGFR in FL-HCC. Formalin-fixed, paraffin-embedded FL-HCC (n = 13) sections were stained with a monoclonal antibody against EGFR. Fluorescence in situ hybridization analysis was performed using probes against EGFR gene and centromeric region of chromosome 7 (CEP 7). Epidermal growth factor receptor and CEP 7 signals were counted in 50 tumor nuclei per case as well as 300 normal hepatocyte nuclei. The EGFR to CEP 7 signal ratio was calculated for each case. Most (92%, 12/13) of FL-HCC showed strong and diffuse staining with anti-EGFR antibody. Fluorescence in situ hybridization was informative in 11 cases, 10 of which showed extra EGFR gene copy numbers (mean, 3.69; range, 3.13-5.0). Epidermal growth factor receptor was overexpressed in all these cases. The mean number of EGFR signals per cell in FL-HCC was double that of normal hepatocytes (3.69 versus 1.80); the mean EGFR/CEP 7 ratio in tumor cells was 1.05. In conclusion, EGFR is strongly overexpressed on the cell membrane in nearly all cases of FL-HCC. Similar gains of chromosome 7 are observed, indicating that the extra EGFR gene copies are due to polysomy rather than gene amplification. The strong expression of EGFR in FL-HCC tumors suggests that they may respond to treatment with EGFR antagonists.     

Evaluation of chromosomal abnormalities by clg-FISH and association with proliferative and apoptotic indexes in multiple myeloma

Eighty-six newly diagnosed multiple myeloma (MM) patients from a public hospital of São Paulo (Brazil) were evaluated by cIg-FISH for the presence of del(13)(q14), t(4;14)(p16.3;q32) and del(17)(p13). These abnormalities were observed in 46.5, 9.3, and 7.0% of the patients, respectively. In order to identify the possible role of del(13)(q14) in the physiopathology of MM, we investigated the association between this abnormality and the proliferative and apoptotic indexes of plasma cells. When cases demonstrating t(4;14)(p16.3;q32) and del(17)(p13) were excluded from the analysis, we observed a trend towards a positive correlation between the proportion of cells carrying del(13)(q14) and plasma cell proliferation, determined by Ki-67 expression (r = 0.23, P = 0.06). On the other hand, no correlation between the proportion of cells carrying del(13)(q14) and apoptosis, determined by annexin-V staining, was detected (r = 0.05, P = 0.69). In general, patients carrying del(13)(q14) did not have lower survival than patients without del(13)(q14) (P = 0.15), but patients with more than 80% of cells carrying del(13)(q14) showed a lower overall survival (P = 0.033). These results suggest that, when del(13)(q14) is observed in a high proportion of malignant cells, it may have a role in determining MM prognosis. Another finding was a statistically significant lower overall survival of patients with t(4;14)(p16.3;q32) (P = 0.026). In the present study, almost half the patients with t(4;14)(p16.3;q32) died just after diagnosis, before starting treatment. This fact suggests that, in São Paulo, there may be even more patients with this chromosomal abnormality, but they probably die before being diagnosed due to unfavorable socioeconomic conditions. This could explain the low prevalence of this chromosomal abnormality observed in the present study.     

The incidence of topoisomerase II-alpha genomic alterations in adenocarcinoma of the breast and their relationship to human epidermal growth factor receptor-2 gene amplification: a fluorescence in situ hybridization study

Clinical and in vitro evidence supports the concept that human epidermal growth factor receptor-2 ( HER2 ) gene amplification prediction of response to anthracycline-based chemotherapy in breast cancer is not a direct effect of HER2 overexpression, but the result of coamplification of topoisomerase II-alpha ( TOP2A ). We investigated the relationship of TOP2A to HER2 genomic alterations by fluorescence in situ hybridization (FISH) and the correlations with polysomic states for chromosome 17 (CEP17). One hundred thirty-eight cases of breast cancer HER2 gene amplified by 2-color FISH ( HER2 /CEP17) were reevaluated with a 3-color probe set ( HER2 /CEP17/ TOP2A ) to investigate the frequency of coamplification and deletion of TOP2A . TOP2A was never amplified in the absence of HER2 amplification and was coamplified with HER2 in 68 (50%) of 137 cases; HER2 gene copy number was higher than the TOP2A copy number ( P < .01). Of the 137 cases with HER2 amplification, 23 (16%) showed a monoallelic deletion of TOP2A . Of the 43 cases not amplified for HER2 , 27 (63%) were CEP17 eusomic, 13 (30%) polysomic, and 3 (7%) monosomic. Of the HER2 nonamplified cases, 2 (5%) showed monoallelic deletion of both the HER2 and TOP2A . The current study demonstrates the complex interrelationship between the HER2 and TOP2A genes in breast cancer. The clinical implications of TOP2A amplification and deletion in breast cancer need to be further defined. If TOP2A gene dosage can be confirmed to correlate with tumor responsiveness to anthracycline-based therapy in the clinical setting, FISH testing for TOP2A status may be warranted to aid in the selection of the most appropriate therapy.     

Fibroblast growth factor receptor 2 gene amplification status and its clinicopathologic significance in gastric carcinoma

Fibroblast growth factor receptor 2 is a member of receptor tyrosine kinase family, and fibroblast growth factor receptor 2 gene amplification or missense mutation has been observed in various human cancers, including gastric carcinoma. Recent studies have shown that anti-fibroblast growth factor receptor 2 agents inhibit tumor progression in various human cancers, such as endometrial carcinoma and gastric carcinoma, which remains one of the most frequent causes of cancer-related death worldwide. We considered that knowledge of the status of fibroblast growth factor receptor 2 gene amplification in gastric carcinoma might aid in targeted cancer therapy. In this study, fibroblast growth factor receptor 2 amplification status was evaluated by fluorescence in situ hybridization in 313 surgically resected gastric carcinoma tissues, and the results were validated by quantitative real-time polymerase chain reaction. In addition, potential associations between clinicopathologic parameters and the presence of fibroblast growth factor receptor 2 amplification were investigated, and survival analysis was performed. Of the 313 cases, 14 (4.5%) showed fibroblast growth factor receptor 2 amplification by fluorescence in situ hybridization. Fibroblast growth factor receptor 2 amplification was found to be associated with a higher pT stage (P = .023), higher pN stage (P = .038), and distant metastasis (P = .009) and to be significantly associated with lower cancer-specific survival by univariate analysis (P = .012). Gastric carcinoma with fibroblast growth factor receptor 2 amplification was found to be associated with advanced disease and a poor prognosis. We believe that the determination of fibroblast growth factor receptor 2 amplification status could allow the identification of a subset of cancers sensitive to targeted fibroblast growth factor receptor 2 inhibitor-based therapy.     

A novel gene mutation in PANK2 in a patient with an atypical form of pantothenate kinase-associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN) disease is an autosomal recessive neurodegenerative disorder with iron storage in the brain due to PANK2 gene mutations. Brain magnetic resonance imaging (MRI) shows the typical “eye-of-the-tiger” sign. The aim of the present study was to describe clinical, MRI and molecular findings in a 26-year-old male with atypical PKAN disease in whom, brain MRI scans showed bilateral pallidal T2-hypointensity with a small central region of T2-hyperintensity, resembling the “eye-of-the-tiger” typical image. Genetic analysis identified two mutations in PANK2: c.1561G>A and c.1663G>A, being the latter never described before. Due to limited phenotype–genotype correlation among patients with movement disorders, if “eye-of-the-tiger” brain MRI is present, PANK2 mutations investigation are needed to confirm PKAN disease.     

Human epidermal growth factor receptor 2 expression in breast cancer: correlation with clinical pathological features

The overexpressed HER2 (human epidermal growth factor receptor 2) is a valuable therapeutic target. Precise assessment of HER2 status is thus crucial in the treatment of breast cancer. In this study, formalin-fixed, paraffin-embedded samples of tumors from 304 breast cancer patients who underwent curative surgery procedures between 2011 and 2014 were tested by immunohistochemistry (IHC) as a primary estimate of HER2 status, followed by fluorescence in situ hybridization (FISH). Concordance rate between IHC and FISH was evaluated. The Χ² test was used to evaluate the correlation between HER2 gene amplification status and different clinical pathological features including: (estrogen receptor) ER and (progesterone receptor) PR expression, age, menopausal status and tumor size. The results show that 84.8% of IHC score 3+ cases and 6.2% of IHC score 0/1+ cases were amplified by FISH. After exclusion of group IHC 2+, the concordance rate between FISH and IHC was 87.4%. There was a significant inverse association between expression of hormone receptors (ER and PR) and HER2 amplification (P < 0.001) among the patients studied. However, no relationship was observed between HER2 amplification and age, menopausal status and tumor size (P > 0.05). The data demonstrate a relatively high level of concordance rate for HER2 testing between FISH and IHC, and HER2 overexpression was associated with the levels of ER and PR.     

Topoisomerase IIalpha gene amplification in gastric carcinomas: correlation with the HER2 gene. An immunohistochemical, immunoblotting, and multicolor fluorescence in situ hybridization study

Topoisomerase IIalpha (topoIIalpha) is an enzyme required for DNA replication and a molecular target for drugs called anthracyclines. The topoIIalpha gene (TOP2A) is located close to the HER-2/neu oncogene (HER2). We assessed gastric cancers to (1) clarify the relationship between gene amplification and protein overexpression of topoIIalpha and HER2; (2) evaluate the correlation between gene amplification and protein overexpression of topoIIalpha; and (3) examine the relationship between the results of immunohistochemistry and Western blot analysis for topoIIalpha. In a combined analysis of immunohistochemistry and fluorescence in situ hybridization on 552 formalin-fixed and paraffin-embedded gastric cancer tissues, 38 cases were found to have HER2 amplification. Further examination by fluorescence in situ hybridization revealed amplification of TOP2A in 13 of the 38 cases. No aberrations in the TOP2A gene were observed in cases without HER2 overexpression, except for one containing a gene deletion. The TopoIIalpha protein-labeling index was not correlated with TOP2A amplification. Fluorescence in situ hybridization was performed on nuclear imprint specimens obtained from 9 cases using simultaneous probes for TOP2A, HER2, and centromere 17. Of these 9 cases, 3 displayed coamplification of TOP2A and HER2, and only 1 of the 3 cases revealed a high expression of topoIIalpha in Western blot. Although patients having gastric adenocarcinoma with TOP2A amplification could be considered suitable for clinical trials, information involving anthracycline therapy is not firmly understood in regards to the status of TOP2A amplification or protein overexpression. Therefore, results of the current study will provide further insight for the clinical application of anthracycline in gastric cancers.     

Primary vulvar Ewing's sarcoma/primitive neuroectodermal tumor in a post-menopausal woman: A case report

Ewing's sarcomas/peripheral primitive neuroectodermal tumors (ES/pPNETs) are high-grade malignant neoplasms rarely found outside the skeletal system. Only 12 cases of vulvar ES/pPNET have so far been reported, all involving children or women of child-bearing age. We describe the case of a 52-year-old woman who was admitted to our hospital for the local excision of a 4 cm vulvar mass, originally thought to be a Bartholin's gland cyst. It was subsequently found to consist of small round cells positive for anti-CD99 antibody, thus suggesting a diagnosis of ES/pPNET. The demonstration of EWSR1 gene translocations by means of fluorescent in situ hybridization excluded small-cell carcinoma, squamous cell carcinoma of the small type, Merkel cell carcinoma, and lymphoblastic lymphoma. After surgery, the patient received six cycles of polychemotherapy and radiotherapy; she is still alive and well after 1 year of follow-up. Our findings underline the crucial role of molecular biology techniques in the differential diagnosis of small round cell tumors in these unusual locations.