Immunohistochemical validation of TLE1, a novel marker, for synovial sarcomas.

BACKGROUND & OBJECTIVES: Logistic and financial constraints limit application of several available immunohistochemical (IHC) markers and molecular analysis in every case of synovial sarcoma, diagnosed in our settings. Recently, TLE1 has been recognized as a robust IHC marker for diagnosing a synovial sarcoma. Here, we present IHC features of synovial sarcomas, including TLE1 expression in these cases and in some other tumours. METHODS: Conventional sections from 42 synovial sarcomas (30 retrospective & 12 prospectively diagnosed) were subjected to TLE1 IHC staining, including 21 tumours confirmed with molecular testing. TLE1 immunostaining was graded from 0, 1+, 2+, 3+, with 2+ or 3+ grades interpreted as positive staining. RESULTS: Of the 42 tumours, 26 (61.9%) were of monophasic spindle cell type, 13 biphasic type (30.9%), two (4.7%) calcifying type and remaining one (2.3%) was a poorly differentiated synovial sarcoma. On immunohistochemistry (IHC), tumours were positive for epithelial membrane antigen (EMA) (26/34, 76.4%), cytokeratin (CK)7 (6/10, 60%), CK/MNF116 (6/21, 28.6%), B cell lymphoma 2 (BCL2) (36/37, 97.3%), cluster of differentiation molecule 99 (MIC2) (23/31, 74.1%) and transducin-like enhancer of split 1 (TLE1) (40/42, 95.2%), while negative for CD34 in all 21 tumours, wherever performed. TLE1 was also positive in tumour controls, including schwannomas (5/5, 100%), neurofibromas (2/2, 100%), malignant peripheral nerve sheath tumors (2/12, 17%) and Ewing sarcomas (4/10, 40%). TLE1 sensitivity for diagnosis of synovial sarcomas was 95.2 per cent. Its overall specificity was 63.7 per cent, whereas with regards to tumors forming its closest differential diagnoses, its specificity was 72 per cent. INTERPRETATION & CONCLUSIONS: Although molecular confirmation is the diagnostic gold standard for synovial sarcoma, TLE1, in view of its high sensitivity may be a useful marker within the optimal IHC panel comprising EMA, BCL2, MIC2, CD34 and CK7, especially on small biopsy samples, for substantiating a diagnosis of synovial sarcoma. Awareness of TLE1 expression in other tumours and its correct interpretation are necessary.

Ewing sarcoma/primitive neuroectodermal tumor of the kidney: clinicopathologic analysis of 34 cases.

The present study describes the clinicopathologic analysis of 34 cases of Ewing sarcoma/primitive neuroectodermal tumor occurring in the kidney. The patients were 21 males and 13 females with an age range of 6 to 44 years. Clinically, patients presented with multiple symptoms including hematuria, pain, and/or lump in the abdomen. Nephrectomy was performed in most of the cases. Grossly, whole of the renal parenchyma was involved by a variegated tumor. Histologically, the tumor was composed of monomorphic, small, and round cells arranged in a variety of patterns. Rosettes, geographical areas of necrosis, and arborizing vascular pattern were the prominent histologic features. The nucleus was monomorphic and round. Anisonucleosis was also noted in some cases. The nucleus was mostly hyperchromatic. A mixture of hyperchromatic and powdery chromatin was noted in few cases. Immunohistochemically, MIC2 (CD99) was positive in 32 of 34 cases followed by neuron-specific enolase (9/12 cases), vimentin (8/14 cases), synaptophysin (1/8 cases), and S-100 protein (1/4 cases). Molecular analysis by reverse transcriptase-polymerase chain reaction that was carried out in 26 cases revealed presence of EWS-FLI-1 type 1 translocation in 12 cases, EWS-FLI-1 type 2 translocation in 10 cases, and both type 1 and type 2 EWS-FLI-1 translocation in 2 cases. Two cases did not demonstrate any translocation. Follow-up data were available for 17 of 34 cases. Local recurrence of the tumor was seen in 4 patients, and 10 patients were recorded to have distant metastasis in various organs, such as lung, bone, and lymph node, during the course of the disease.

Assessment of HER-2/neu status in breast cancer using fluorescence in situ hybridization & immunohistochemistry: Experience of a tertiary cancer referral centre in India.

BACKGROUND & OBJECTIVES: Determination of HER2 status in breast cancer has become important to identify potential candidates for anti-HER2 therapy. In this study we compared fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for the determination of HER2 status in breast cancer patients referred to a tertiary care referral centre. METHODS: A total of 200 cases of invasive breast cancer were evaluated for HER2 status using IHC and FISH and results were compared. RESULTS: The IHC 3+ (93.9%) and IHC negative (85.9%) cases showed good concordance with the corresponding FISH results; while 66.6 per cent of IHC 2+ cases showed gene amplification by FISH. In addition, hormone receptor expression and HER2 gene status showed a statistically significant inverse association (P<0.05). INTERPRETATION & CONCLUSION: These findings reaffirm IHC as a prudent first-step to screen tissue samples for HER2 status and to determine suitability for technically demanding FISH test and the dual coloured FISH as a gold standard for determination of HER2/neu status in IHC equivocal cases of breast carcinoma.

Synovial sarcoma of the kidney.

The renal parenchyma is a rare site of origin for primary synovial sarcoma (SS). The present study describes the clinicopathologic, immunohistochemical, and molecular analysis of 7 cases of SS occurring in the kidney. There were 5 female and 2 male patients, with an age range of 15 to 46 years. They presented with solitary renal masses ranging in size from 10.0 cm to 17.0 cm in greatest dimension. Radical nephrectomy was performed in all cases. On gross examination, tumors were large, partially necrotic, and were seen to contain smooth-walled cysts in 4 cases. Histologically, the tumors were characterized by monomorphic spindle cells with indistinct cell borders arranged in intersecting nodular foci with hypocellular myxoid areas, together with a prominent hemangiopericytomatous pattern. The cysts were lined by hobnailed cells with eosinophilic cytoplasm. Immunohistochemically, BCL-2 was positive in all 6 cases in which it was performed, followed by vimentin (4/5 cases), MIC2 (CD99; 2/5 cases), calponin (2/2 cases), and epithelial membrane antigen (1/4 cases). Stains for cytokeratin and CD34 were consistently negative. Reverse transcription-polymerase chain reaction (RT-PCR) using RNA extracted from formalin-fixed paraffin-embedded tissues was carried out in 4 cases and SYT-SSX fusion gene transcript, which is the diagnostic hallmark of SS, was detected. Two patients developed pulmonary metastasis and died 6 and 12 months after diagnosis, respectively. This series of cases is distinct in terms of its morphological spectrum and confirmation by molecular technique.

The effect of biological heterogeneity on R-CHOP treatment outcome in diffuse large B-cell lymphoma across five international regions.

Addressing the global burden of cancer, understanding its diverse biology, and promoting appropriate prevention and treatment strategies around the world has become a priority for the United Nations and International Atomic Energy Agency (IAEA), the WHO, and International Agency for Research on Cancer (IARC). The IAEA sponsored an international prospective cohort study to better understand biology, treatment response, and outcomes of diffuse large B-cell lymphoma (DLBCL) in low and middle-income countries across five UN-defined geographical regions. We report an analysis of biological variation in DLBCL across seven ethnic and environmentally diverse populations. In this cohort of 136 patients treated to a common protocol, we demonstrate significant biological differences between countries, characterized by a validated prognostic gene expression score (p < .0001), but International Prognostic Index (IPI)-adjusted survivals in all participating countries were similar. We conclude that DLBCL treatment outcomes in these populations can be benchmarked to international standards, despite biological heterogeneity.

Evidence for cell-free nucleic acids as continuously arising endogenous DNA mutagens.

There is extensive literature to show that nucleic acids can be taken up by cells under experimental conditions and that foetal DNA can be detected in maternal tissues. The uptaken DNA can integrate into host cell genomes and can be transcribed and translated into proteins. They can also cause chromosomal damage and karyotype alterations. Cell-free nucleic acids (cfNAs)-based non-invasive DNA diagnostic techniques are being extensively researched in the field of cancer with the potential to advance new prognostic parameters and direct treatment decisions. However, whether extracellular cfNAs that are released into circulation from dying cells as a consequence of normal physiology have any functional significance has not been explored. A recent study has demonstrated that circulating cfNAs have the ability to cause DNA damage and mutagenesis by illegitimately integrating into healthy cells of the body, thereby acting as mobile genetic elements. Fluorescently-labeled cfNAs isolated from sera of cancer patients and healthy volunteers were shown to be readily taken up by host cells followed by activation of a DNA-damage-repair-response which led their large scale integration into the host cell genomes. The latter caused dsDNA breaks and apoptosis in cells in vitro and in those of vital organs when injected intravenously into mice. Cell-free chromatin was consistently more active than cell-free DNA, while cfNAs derived from cancer patients were significantly more active than those from healthy volunteers. This study suggests that circulating extracellular cfNAs act as physiological continuously arising DNA mutagens with implications for ageing, cancer and a host of other degenerative human pathologies.

Protocol for qRT-PCR analysis from formalin fixed paraffin embedded tissue sections from diffuse large b-cell lymphoma: Validation of the six-gene predictor score.

As a part of an international study on the molecular analysis of Diffuse Large B-cell Lymphoma (DLBCL), a robust protocol for gene expression analysis from RNA extraction to qRT-PCR using Formalin Fixed Paraffin Embedded tissues was developed. Here a study was conducted to define a strategy to validate the previously reported 6-gene (LMO2, BCL6, FN1, CCND2, SCYA3 and BCL2) model as predictor of prognosis in DLBCL. To avoid variation, all samples were tested in a single centre and single platform. This study comprised 8 countries (Brazil, Chile, Hungary, India, Philippines, S. Korea, Thailand and Turkey). Using the Kaplan-Meier and log rank test on patients (n=162) and two mortality risk groups (with those above and below the mean representing high and low risk groups) confirmed that the 6-gene predictor score correlates significantly with overall survival (OS, p<0.01) but not with event free survival (EFS, p=0.18). Adding the International Prognostic Index (IPI) shows that the 6-gene predictor score correlates significantly with high IPI scores for OS (p<0.05), whereas those with low IPI scores show a trend not reaching significance (p=0.08). This study defined an effective and economical qRT-PCR strategy and validated the 6-gene score as a predictor of OS in an international setting.

Clinicopathological and molecular spectrum of ewing sarcomas/PNETs, including validation of EWSR1 rearrangement by conventional and array FISH technique in certain cases.

Over the years, a wide clinicopathological spectrum has been identified within Ewing family of tumors (EFTs). As these tumors are chemosensitive, their correct and timely identification is necessary. The aims of this study were (1) to present the diverse clinicopathological and molecular profile of EFTs in our settings, (2) to identify a pragmatic approach for diagnosing EFTs, especially for application of ancillary techniques, namely RT-PCR for specific transcripts (EWS-FLI1, EWS-ERG) and FISH for EWSR1 gene rearrangement, in certain cases and (3) to show the utility of tissue microarray in establishing a new FISH test. Fifty-eight EFTs were identified in 38 males and 20 females within an age-range of 1-65 years (median, 16), mostly in lower extremities (14) (24.1 %). Therapeutically, most patients underwent neoadjuvant chemotherapy with subsequent surgery. Histopathologically, diagnosis of EFTs was initially offered in 41/58 (70.6 %) tumors. On review, 59 % tumors showed diffuse pattern, while 41 % displayed rosettes. Immunohistochemically, tumor cells were mostly diffusely positive for CD99 (48/52) (92.3 %); FLI-1 (17/18) (94.4 %); variably for BCL2 (16/18) (88.8 %), synaptophysin (6/20) (35 %), S100-P (2/7) (28.5 %), CD56 (2/5) (40 %), NSE (2/5) (40 %), calponin (3/4) (75 %), EMA (5/24) (20.8 %) and CK (3/24) (12.5 %), the latter two mostly focally. Fifty five tumors were EWS-FLI1 positive, while a single tumor was EWS-ERG positive. Sensitivity for PCR was 61 %. EWSR1 rearrangement was detected by FISH in 12/13 Ewing sarcomas/PNETs. Sensitivity for EWSR1 test was 92.3 % and specificity was 100 %. Thirty-eight tumors, including 14 molecular confirmed EFTs and 21 other tumors were tested for EWSR1 rearrangement. Among 21 unrelated tumors, EWSR1 rearrangement was detected in few myoepithelial tumors, occasional desmoplastic small round cell tumor and an extraskeletal myxoid chondrosarcoma. Further, a tissue microarray with a separate set of 8 EFTs, confirmed at another laboratory was analysed for validation of EWSR1 rearrangement test. 23/28 (82.1 %) tissue cores of the tissue microarray, stained by FISH were interpretable, including EWSR1 rearrangement, detected in 20/28 tissue cores; not detected in 3 liver cores and uninterpretable in 5 (17.8 %) cores. Classical EFTs can be diagnosed with diffuse, membranous CD99 positivity, intranuclear FLI1 positivity and LCA negativity in malignant round cells. In unconventional cases, it is indispensable to reveal the concomitant fusion m-RNA by RT-PCR. In case of negative molecular results, it is necessary to prove EWSR1 rearrangement by FISH. These tests should be interpreted with clinicopathological correlation. Tissue microarrays for FISH are useful during validation of a new test, especially when sarcomas like EFTs show less genetic heterogeneity within tumor cells.

Primary vaginal Ewing's sarcoma or primitive neuroectodermal tumor in a 17-year-old woman: a case report.

INTRODUCTION: Primary Ewing's sarcoma or primitive neuroectodermal tumor of the genital tract of women is uncommon. Rarer still is its occurrence in the vagina, with only five cases described so far. Out of these, only one case was confirmed using molecular analysis. CASE PRESENTATION: We present an extremely rare case of Ewing's sarcoma or primitive neuroectodermal tumor in a 17-year-old Indian girl. She presented with a vaginal mass that was initially diagnosed as a malignant round cell tumor. Immunohistochemistry showed diffuse positivity for vimentin, membranous positivity for MIC2, and positivity for BCL2 and FLI-1. On the other hand, she was negative for cytokeratin, epithelial membrane antigen, desmin, Myo D-1, myogenin and smooth muscle actin. A diagnosis of primitive neuroectodermal tumor was thus offered. Furthermore, a molecular analysis of our patient using reverse transcription-polymerase chain reaction technique showed positivity for t(11; 22) (q24; q12) (EWSR1-FLI1), thus confirming the diagnosis of a Ewing's sarcoma/primitive neuroectodermal tumor. Our patient was offered chemotherapy on Institutional protocol EFT 2001. CONCLUSION: This is a rare case of primary vaginal Ewing's sarcoma or primitive neuroectodermal tumor, which was confirmed with molecular analysis, in the youngest patient known so far. This study reinforces the value of integrating morphological features with membranous MIC2 positivity, along with application of molecular techniques in objective identification of an Ewing's sarcoma or primitive neuroectodermal tumor at uncommon sites.