A single tertiary institution review of the international system for serous fluid cytopathology and the impact of cell block and ancillary studies on its performance.

INTRODUCTION: We sought to assess the utility of the International System for Serous Fluid Cytopathology (TIS) in the context of our department's routine practice. MATERIALS AND METHODS: We examined 1028 archived effusion cytology (pleural, peritoneal, and pericardial) cases from 2018 to 2019, and re-classified them along the international system into the following diagnostic categories: nondiagnostic (ND), negative for malignancy (NFM), atypia cells of undetermined significance (AUS), suspicious for malignancy (SFM), and malignant (MAL). RESULTS: The full distribution of the cases examined was as follows: ND 2.0%; NFM 66.1%; AUS 6.0%; SFM 4.7%; MAL 21.2%. Overall risk of malignancy for each category was calculated as: ND 30.0%; NFM 18.0%; AUS 61.9%; SFM 100%; MAL 94.4%. The overall performance attributes of TIS were as follows: sensitivity 57.1%; specificity 98.3%; positive predictive value 94.4%; negative predictive value 82.0%; diagnostic accuracy 84.5%. CONCLUSIONS: The new classification was simple and intuitive to use and our results appear to fall within the expected ranges of the new guidelines, with risk of malignancy and accuracy comparable to similar studies. The availability of a cell block allowed for refinement of the diagnosis in a majority of cases with equivocal cytology, though this was dependent on the cell yield.

Epithelial-mesenchymal transition and cancer stem cell interactions in breast phyllodes tumours: immunohistochemical evaluation of EZH2, EZR, HMGA2, CD24 and CD44 in correlation with outcome analysis.

AIM: Phyllodes tumours (PTs) categorised as benign, borderline and malignant, account for 1% of all breast tumours. Histological assessment does not always predict tumour behaviour, hindering determination of the clinical course and management.Epithelial-mesenchymal transition (EMT) is an important process during embryogenesis. Dysregulation of EMT causes loss of cell polarity, decreased intercellular adhesion, increased motility and invasiveness, promoting tumour progression. Similarly, cancer stem cells (CSCs) promote tumour growth, resistance and recurrence. The aim of this study is to evaluate expression of CSC markers; enhancer of zeste homolog 2 (EZH2), CD24 and CD44 and EMT associated proteins; ezrin (EZR) and high-mobility group AT-hook 2 (HMGA2) in PTs. METHOD: Uing tissue microarray sections, immunohistochemistry was performed on 360 PTs. Epithelial and stromal expressions of EZH2, EZR, HMGA2, CD24 and CD44 were evaluated to assess their impact on disease progression and behaviour in correlation with clinicopathological parameters. RESULTS: Stromal expression of EZH2, EZR and HMGA2 was observed in 73 (20.3%), 53 (14.7%) and 28 (7.8%) of tumours, epithelial expression in 121 (35.9%), 3 (0.8%) and 351 (97.5%) tumours, respectively. CD24 and CD44 staining was absent in both components. CONCLUSION: Expression of biomarkers correlated significantly with aggressive tumour traits such as stromal hypercellularity, atypia, mitoses and permeative tumour borders.Stromal expression of EZH2 and EZR shortened disease-free survival and overall survival; HMGA2 expression did not alter patient survival. EZH2 and EZR may thus be useful in predicting PT behaviour.

An automated staining protocol for seven-colour immunofluorescence of human tissue sections for diagnostic and prognostic use.

Multiplex immunofluorescence (mIF) allows simultaneous antibody-based detection and quantification of the expression of up to six markers, plus a nuclear counterstain, on a single tissue section. Recent studies have shown the potential for mIF to advance our understanding of complex disease processes, including cancer. It is important that the technique be standardised and validated to facilitate its transition into clinical use. Traditional approaches to mIF rely on manual processing of sections, which is time-consuming and a source of significant variation between samples/individuals. Here we determined if an automated diagnostic tissue stainer could be used for mIF incorporating tyramide signal amplification (TSA), and how the final image quality compared with sections stained semi-automatically or manually. Using tissue microarrays of fixed human breast tumour sections, we observed comparable antibody labelling between the diagnostic autostainer and manual technique. The diagnostic autostainer produced higher signal intensity with similar spectral unmixing efficiency. We also found that microwave treatment for antibody stripping during TSA labelling could be replaced by the heating option incorporated within the diagnostic-use autostainer. These data show that diagnostic autostainers used for traditional immunohistochemistry protocols can be readily adapted to achieve rapid preparation of high-quality sections using a TSA method for clinical mIF.

Clinicopathological characteristics of oestrogen receptor negative, progesterone receptor positive breast cancers: re-evaluating subsets within this group.

AIMS: The presence of oestrogen and progesterone receptors (ER, PR) in breast carcinoma is an important prognostic indicator as well as a predictor of likely response to hormonal treatment. Current ambiguity surrounds ER-negative (-)/PR-positive (+) breast cancer (BC) as to whether this phenotype exists as a distinct entity. The independent predictive value of PR for treatment considerations is also in question, as some investigators believe ER status to be the single most important therapeutic predictive factor in BC. We undertook this study to determine the existence of ER(-)/PR(+) BC and the prognostic effect, if any, of this phenotype. METHODS: We investigated 267 archival documented ER(-)/PR(+) BCs diagnosed between January 1994 and July 2009. Histological slides were retrieved and reviewed. Tissue microarrays were constructed by selecting two 1 mm cores of tumour per case. Repeat immunohistochemistry was performed for confirmation of the ER(-)/PR(+) status. Clinicopathological parameters including age, ethnicity, tumour size, histological grade, histological subtype, associated ductal carcinoma in situ, lymphovascular invasion and lymph node status were evaluated. RESULTS: On repeat immunohistochemistry, 92 tumours were confirmed as ER(-)/PR(+) BCs. This phenotype accounted for 1.1% of all BC phenotypes and exhibited different clinicopathological features and survival outcome when compared with other phenotypes. ER(-)/PR(+) tumours showed a trend for an early recurrence and poorer overall survival as compared with the patients with ER(+)/PR(+) tumours and similar to ER(-)/PR(-) tumours. CONCLUSIONS: Our findings suggest that ER(-)/PR(+) BCs exist, although rare, with distinct pathological and clinical characteristics from patients with ER(+)/PR(+) BCs.

A case of small bowel metastasis from spinal Ewing sarcoma causing intussusception in an adult female.

BACKGROUND: Ewing sarcomas are highly aggressive malignant tumours occurring predominantly in the long bones of the extremities in children and young adults. About 20 % of patients will present with metastases at diagnosis with the commonest sites being the lungs, bone and bone marrow. Cases of primary small bowel Ewing sarcomas have been described but are nonetheless exceedingly rare, even more so cases of metastasis to the small bowel. CASE PRESENTATION: We describe a case of vertebral Ewing sarcoma in a 44 year-old female which metastasized to the jejunum causing intussusception. CONCLUSIONS: Ewing's sarcoma is highly aggressive and presence of metastases, overt or subclinical, is thought to be present in almost all patients at diagnosis. As evidenced by our patient, metastatic disease can progress rapidly to cause further complications and confer a poorer survival. The possibility of metastasis, no matter how rare or unlikely the site is, should be considered and actively investigated to expedite treatment of the primary disease.

Sentinel lymph nodes with isolated tumour cells and micrometastases in breast cancer: clinical relevance and prognostic significance.

AIM: We performed a retrospective review to determine the prognostic significance of isolated tumour cells (ITCs) and micrometastases to the sentinel lymph nodes of patients with breast cancer. METHODS: A total of 1044 patients with a diagnosis of invasive carcinoma of the breast who underwent surgical treatment including the sentinel lymph node biopsy procedure from July 2004 to October 2009 were included in the study. RESULTS: In 710 (68%) patients, no metastasis was seen to the sentinel lymph nodes. ITCs were detected in 22 (2.1%) patients, micrometastasis in 52 (5.0%) and macrometastases in 260 (24.9%). With a median follow-up of 28.8 months, disease recurrence was seen in 38 (3.6%) patients and 15 (1.5%) patients died of disease. No disease recurrence or deaths were recorded in women with ITCs in sentinel lymph nodes. In the micrometastasis group, 2 patients suffered disease recurrence and both died of disease. CONCLUSIONS: We conclude that ITCs in the sentinel lymph nodes did not adversely impact disease free and overall survivals. Although only 2 recurrences with subsequent death occurred in the micrometastasis group, it may suggest a propensity for presence of micrometastases to augur a worse outcome, and justifies continued segregation of ITCs from micrometastasis.

Predicting the likelihood of additional lymph node metastasis in sentinel lymph node positive breast cancer: validation of the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram.

AIM: To identify important clinicopathological parameters that are most helpful in predicting additional non-sentinel lymph node (SLN) metastasis among patients with a positive SLN biopsy in the Singapore breast cancer population. METHODS: A total of 1409 patients who underwent SLN biopsy were reviewed over a 5 year period from July 2004 to October 2009. A Singapore General Hospital (SGH) nomogram was developed from predictors in the Memorial Sloan-Kettering Cancer Centre (MSKCC) nomogram using 266 patients with primary invasive breast cancer and a positive SLN biopsy who subsequently had an axillary lymph node dissection. The SGH nomogram was calibrated using bootstrapped data, while the MSKCC nomogram was calibrated using SGH data. The performance of these two nomograms was compared with the calculation of the area under the receiver-operator characteristics curve and adequacy indices. RESULTS: The MSKCC nomogram achieved an area under the curve (AUC) of 0.716 (range 0.653-0.779) in our study population, while the SGH nomogram, which used only three pathological parameters, lymphovascular invasion, number of positive and negative SLN biopsies, achieved an AUC of 0.750 (range 0.691-0.808). The SGH nomogram with a higher adequacy index (0.969) provided better estimates compared with the MSKCC nomogram (0.689). CONCLUSIONS: The use of the MSKCC nomogram was validated in our local patient population. The SGH nomogram showed promise to be equally, if not, more predictive as a model in our own population, while using only three pathological parameters.

Cutaneous squamous cell carcinoma associated with proliferation of osteoclast-like giant cells.

Proliferation of osteoclast-like giant cells in a cutaneous squamous cell carcinoma is a rare phenomenon and so far only four cases have been reported. In previous reports, osteoclast-like giant cells were admixed with sarcomatoid component of squamous cell carcinoma and it is therefore debatable if the osteoclast-like giant cells represent a reactive phenomenon or a part of the malignant tumour. A case of cutaneous squamous cell carcinoma associated with osteoclast-like giant cells is reported. However, sarcomatous component of squamous cell carcinoma was not identified in this case. Morphologically, the osteloclast-like giant cells appeared to be benign. The localization of the squamous cell carcinoma and the osteoclastic-like giant cells were separate from one another. Immunohistochemically, squamous cell carcinoma was positive for high molecular weight cytokeratin, cytokeratin-5 and p63, whereas the osteloclast-like giant cells were positive for histiocyte marker CD68 and vimentin and negative for epithelial markers supporting a reactive nature of osteoclast-like giant cells to the cutaneous malignancy.

Happy ending of life-threatening upper GI bleeding.

Strongyloides stercoralis is an intestinal nematode in humans, and estimated about tens of millions of people are infected worldwide. This parasite is endemic in tropical or temperate and subtropical climates like Bangladesh. The authors report a 33-year-old man who presented with recurrent life-threatening upper gastrointestinal bleeding from gastric infection by S stercoralis.

HER2/neu revisited: quality and interpretive issues.

BACKGROUND: Immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH) are the only tests currently approved by the US Food and Drug Administration for classifying which patients will benefit from trastuzumab therapy. The accuracy of these two testing methods can be adversely affected by a variety of pre-analytical, analytical and post-analytical factors. According to the latest published recommendations of the panel of the Joint Committee of the American Society of Clinical Oncology and College of American Pathologists for HER2/neu testing, laboratories performing IHC and FISH for HER2/neu status in breast cancer are now required to have a high concordance of at least 95% between IHC and FISH, significantly higher than that in the published literature. AIM: To perform a retrospective analysis of the concordance of IHC and FISH analysis for HER2/neu at Singapore General Hospital and review potential causes of disparity between these two methods. METHOD: A retrospective review of a total of 106 invasive ductal carcinomas evaluated for HER2/neu at the Department of Pathology, Singapore General Hospital between 2007 and 2008 were included in the study. The initial HER2/neu immunostained slides were reviewed independently without knowledge of FISH results, and concordance between IHC and FISH was determined. RESULTS: Concordance between IHC and FISH assay was excellent and within the published range (104/106=98.1%). The discordant cases represent a well-recognised subset of genetic heterogeneity in HER2/neu, which is known to contribute to positive IHC and negative FISH tests.