1.Detection of the human papillomavirus in cervical carcinoma: a comparison between non-isotopic in-situ hybridisation and polymerase chain reaction as methods for detection in formalin-fixed, paraffin-embedded tissues.
Phaik-Leng Cheah ; Lai-Meng Looi
The Malaysian journal of pathology 2008;30(1):37-42
Cervical carcinoma, the second most common malignancy in Malaysian females, is aetiologically linked to the human papillomavirus (HPV). A study was conducted at the Department of Pathology, University of Malaya Medical Centre to compare the identification of HPV 6, 11, 16 and 18 in 40 archived formalin-fixed, paraffin-embedded cervical carcinoma by non-isotopic in-situ hybridisation (NISH) and polymerase chain reaction (PCR). HPV L1 ORF consensus PCR was also carried in cases which were negative on HPV type-specific PCR. NISH detected HPV 16 in 13 (32.5%) cases with one case demonstrating a concomitant HPV 18. beta-globin DNA PCR was carried out on the same paraffin block as for NISH in 27 cases and on a different paraffin block in 13, with amplification in 9 of the former and 3 of the latter. Thus only 12 cases were subjected to further HPV PCR. HPV was detected in 10 (83.3%) with HPV 16 in 9 cases and HPV L1 ORF in one. When using the same paraffin block for both methods of HPV detection, NISH detected HPV in 6 and PCR in 7. NISH failed to detect HPV in a case detected by PCR. 2 cases were negative for HPV using both methods. Hence, HPV detection results by NISH and PCR were concordant in 88.9%. Interestingly, NISH detected HPV in 2 cases with non-amplifiable beta-globin DNA. Using an alternative paraffin block for HPV PCR from NISH, HPV DNA was detected in 3 cases, two of which also showed type-specific positivity on NISH. The third case did not reveal type-specific positivity with NISH or PCR but demonstrated HPV DNA on L1 ORF consensus PCR. It thus appears that PCR and NISH can be successfully used to detect HPV in formalin-fixed, paraffin-embedded tissue and in the presence of intact DNA NISH may be as sensitive as PCR.
Papillomavirus, Human
;
Polymerase Chain Reaction
;
DNA
;
Open Reading Frames
;
Cervical Cancer
2.Historical development of the renal histopathology services in Malaysia.
Lai-Meng Looi ; Phaik-Leng Cheah
The Malaysian journal of pathology 2009;31(1):11-6
Western-style medicine was introduced to Malaya by the Portuguese, Dutch and British between the 1500s and 1800s. Although the earliest pathology laboratories were developed within hospitals towards the end of the 19th Century, histopathology emerged much later than the biochemistry and bacteriology services. The University Departments of Pathology were the pioneers of the renal histopathology diagnostic services. The Department of Pathology, University of Malaya (UM) received its first renal biopsy on 19 May 1968. Hospital Universiti Kebangsaan Malaysia (HUKM) and Hospital Universiti Sains Malaysia (HUSM) started their services in 1979 and 1987 respectively. It is notable that the early services in these University centres caterred for both the university hospitals and the Ministry of Health (MOH) until the mid-1990s when MOH began to develop its own services, pivoted on renal pathologists trained through Fellowship programmes. Currently, key centres in the MOH are Kuala Lumpur Hospital, Sultanah Aminah Hospital Johor Bahru and Malacca Hospital. With the inclusion of renal biopsy interpretation in the Master of Pathology programmes, basic renal histopathology services became widely available throughout the country from 2000. This subsequently filtered out to the private sector as more histopathologists embraced private practice. There is now active continuing professional development in renal histopathology through clinicopathological dicussions, seminars and workshops. Renal research on amyloid nephropathy, minimal change disease, IgA nephropathy, fibrillary glomerulonephritis, lupus nephritis and microwave technology have provided an insight into the patterns of renal pathology and changing criteria for biopsy. More recently, there has been increasing involvement of renal teams in clinical trials, particularly for lupus nephritis and renal transplant modulation.
Renal
;
Histopathology
;
Hospitals
;
Malaysia
;
Pathology procedure
3.Significance of Bcl-2 and Bax proteins in cervical carcinogenesis: an immunohistochemical study in squamous cell carcinoma and squamous intraepithelial lesions.
Phaik-Leng Cheah ; Lai-Meng Looi
The Malaysian journal of pathology 2006;28(1):1-5
Sixteen low grade (LSIL), 22 high grade (HSIL) squamous intraepithelial lesions, 28 invasive (13 stage I and 15 stage II-IV) squamous cell carcinoma (SCC) and 15 benign cervices were immunohistochemically studied for involvement of Bcl-2 and Bax proteins in cervical carcinogenesis. 4-microm sections of the cases were immunostained for Bcl-2 (Clone 124: Dako) and Bax (Dako) and staining intensity was rated as 1 (light), 2 (moderate) and 3 (strong) and percentage cellular staining as 0 (negative), 1 (1-25%), 2 (26-50%), 3 (51-75%) and 4 (>75%) with score derived by multiplying staining intensity and percentage positivity. The cut-off value, indicating upregulated expression, was computed as >2 for Bcl-2 and >8 for Bax. Bcl-2 was upregulated (p < 0.05) in HSIL and Bax in SCC when compared with benign cervical squamous epithelium. Bcl-2 expression was confined to the lower third of the epithelium in the benign cervices and LSIL. In HSIL, expression reached the middle and upper thirds. 4 (30.8%) HSIL with upregulated Bcl-2 demonstrated intensification of staining around the basement membrane. SCCs showed "diffuse" (evenly distributed) or "basal" (intensified staining around the periphery of the invading tumour nests) expression of Bcl-2. Of the 5 SCCs with upregulated Bcl-2, 1 of 2 (50%) stage I and 3 (100%) stage II-IV tumours exhibited the "basal" pattern. Benign cervical squamous epithelium, LSIL, HSIL and SCC showed a generally diffuse Bax expression. Thus, Bcl-2 and Bax appeared to be upregulated at different stages of cervical carcinogenesis, Bcl-2 in HSIL and Bax after invasion. Intensification of staining of Bcl-2 at the basement membrane in some HSIL and SCC is interesting and may augur for increased aggressiveness.
seconds
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Staining
;
stratum corneum chymotryptic enzyme
;
Benign
;
Diagnostic Neoplasm Staging
4.Computer-linked image analysis of nuclear area: is there a use in diagnosis and grading of hepatocellular carcinoma?
Phaik-Leng Cheah ; Lai-Meng Looi
The Malaysian journal of pathology 2007;29(1):37-40
Hepatocellular carcinoma (HCC) ranks as the fifth most common cancer with an increasing frequency worldwide. "Nuclear atypia", one of the critical features in histological diagnosis of malignancy and grading of the tumour, is generally ascertained through eyeballing. A study was conducted at the Department of Pathology, University of Malaya Medical Centre to assess whether nuclear area, (surrogate measure for nuclear size) and standard deviation (surrogate measure for nuclear pleomorphism) when objectively measured via computer-linked image analysis differs between (1) benign and malignant liver cells and (2) different grades of HCC. A 4-microm thick H&E stained section of 52 histologically re-confirmed HCC with 36 having benign, non-dysplastic surrounding liver were analysed using the Leica Q550 CW system. 10 consecutive non-overlapping, non-mitotic and non-apoptotic nuclei of HCC and surrounding benign hepatocytes respectively were manually traced at 400x magnification on the computer monitor and the nuclear area for the particular cell computed in arbitrary units by the Leica QWIN software. A total of 360 benign hepatocytic nuclei, 240 low grade HCC and 280 high grade HCC nuclei were traced. The mean nuclear area of the benign hepatocytes (37.3) was significantly smaller (p < 0.05) than that of both low grade (65.2) and high grade HCC (80.0). In addition, the mean nuclear area of high grade HCC was significantly larger (p < 0.05) than the low grade HCC. SD of the nuclear areas was lowest in benign hepatocytes (9.3), intermediate in low grade HCC (25.0) and highest in high grade HCC (25.6). These findings indicate that computer-linked nuclear measurement may be a useful adjunct in differentiating benign from malignant hepatocytes, in particular in small biopsies of well-differentiated tumours, and in predicting survival after surgical resection and transplant.
Grade
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Benign
;
Computers
;
Malignant Neoplasms
;
Cancer cells grading system
5.A Comparison Of 1995 WHO Classification With 2003 ISN/Rpsclassification Of Lupus Nephritis: A Single Centre Observation
Tak-Kuan Chow ; Lai-Meng Looi ; Phaik-Leng Cheah
The Malaysian Journal of Pathology 2015;37(3):239-246
Background: In the past, lupus nephritis was histologically classified according to the 1995 WHO
Classification. With the introduction of the 2003 ISN/RPS Classification, many nephropathology
services converted to this new classification. This study was undertaken to compare both classification
systems in a single centre practice. Methods: 103 consecutive adequate renal biopsies initially
reported as lupus nephritis in the Department of Pathology, Faculty of Medicine, University of
Malaya were reassessed using the criteria of both the 1995 WHO Classification and the 2003 ISN/
RPS Classification. Results: The relative prevalence for each class using the WHO Classification
were: Class I (1%), Class II (8.7%), Class III (6.8%), Class IV (60.2%), Class V (20.4%), Class VI
(2.9%) while the prevalence using the 2003 ISN/RPS Classification were: Class I (1%), Class II
(8.7%), Class III (6.8%), Class IV (61.2%), Class V (21.3%), Class VI (1%). Both classifications
were essentially comparable with regards to Classes I, II and III. The differences in Classes IV, V and
VI were significant in potential to alter patient management. The identification of segmental lesions
(Class IV-S) over and above a global nephritis (Class IV-G) deserves more focused clinicopathological
studies to gauge whether these groups have different clinical manifestations and outcomes. With
regards Class V, the ISN/RPS system, by requiring that all mixed classes be stipulated in the
diagnostic line, minimizes the chances of patients missing out on additional treatment. The ISN/
RPS system has stricter criteria for Class VI, which again minimizes patients missing out on therapy.
On the whole, the ISN/RPS system is more user-friendly as criteria are more clearly defined which
translates to more benefits to patient care.
6.Telomerase activation in neoplastic cell immortalization and tumour progression.
Lai Meng Looi ; Min-Hwei Ng ; Phaik-Leng Cheah
The Malaysian journal of pathology 2007;29(1):33-5
The unique ability of tumour cells to proliferate indefinitely is crucial to neoplastic progression as it allows these cells to express the aggressive properties of cancer without the censure of physiological ageing. This is in contrast to normal somatic cells which are subject to a "mitotic clock," a phenomenon that has been linked to telomeric shortening after each round of cell replication, so that eventually the loss of genetic material reaches a critical stage and the cells undergo senescence and cell death. A study was conducted to investigate the role of telomerase, an RNA-containing enzyme that restores the telomere length, in the neoplastic cell immortalization and progression process. Fresh human tissue samples taken from excision specimens received by the Department of Pathology, University of Malaya Medical Centre, were investigated for telomerase activity using a commercial Telomerase PCR-ELISA kit (Boehringer Mannheim). Specimens comprised 33 breast lesions (10 infiltrating breast adenocarcinoma, 13 fibroadenoma and 10 non-neoplastic breast tissue), 27 colonic lesions (17 colonic adenocarcinoma and 10 non-neoplastic colonic mucosa) and 42 cervical lesions (20 cervical carcinoma and 22 non-neoplastic cervical tissues). Telomerase activity was found in 6 (60%) of 10 breast carcinomas, 6 (46%) of 13 fibroadenomas, none of the 10 nonneoplastic breast samples, 3 (17.6%) of 17 colon carcinomas and none of the 10 non-neoplastic colonic mucosal samples, 12 (60%) of 20 cervical carcinoma and 3 (13.6%) of 22 non-neoplastic cervical samples. 5/10 (50%) Stage I, 4/7 (57%) Stage II, 2/2 (100%) Stage III and 1/1 (100%) Stage IV cervical carcinomas showed telomerase activity. These findings support a contributory role for telomerase in tumourigenesis with activation occurring from neoplastic transformation and increasing with tumour progression.
Telomerase
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seconds
;
Breast
;
neoplastic cell
;
Progression
7.CD133 marks for colorectal adenocarcinoma
Man-Fong Chew ; Kean-Hooi Teoh ; Phaik-Leng Cheah
The Malaysian Journal of Pathology 2012;34(1):25-28
CD133, a marker which has been advocated to mark colorectal carcinoma “stem or tumour initiating
cells” is amongst the frequently studied markers in colorectal cancer. A study was conducted at
the Department of Pathology, University of Malaya Medical Centre to determine the expression of CD133 in 56 archived, formalin-fi xed, paraffi n-embedded colorectal adenocarcinoma in comparison with adjacent benign colorectal epithelium by immunohistochemical staining for CD133 expression. CD133 immunopositivity was determined as staining at the glandular luminal surface or in the
intraluminal debris. Expression was semiquantitated for (1) proportion of CD133 immunopositivity in the malignant or adjacent benign colorectal epithelium and (2) intensity of staining. The fi nal score of CD133 immunopositivity was arbitrarily taken as proportion of CD133 immunopositivity multiplied by intensity of staining in both the malignant and adjacent benign colorectal epithelium.CD133 expression was observed in signifi cantly increased frequency in 49 (87.5%) colorectal
adenocarcinoma compared with 15 (26.8%) of the adjacent benign colorectal epithelium (p<0.05). In terms of immunopositivity score (proportion of CD133 immunopositivity multiplied by intensity of staining), colorectal adenocarcinoma had a mean arbitrary score of 8.5 which was signifi cantly higher than the mean immunopositivity score of 0.5 of the adjacent benign colorectal epithelium (p<0.05). In addition, the maximum immunopositivity score for the adjacent benign colorectal
epithelium was 4, while 38 (67.9%) of colorectal adenocarcinoma had scores >4. This study shows
that CD133 is able to mark colorectal adenocarcinoma but it is still unclear at this juncture whether
CD133 is indeed a marker for colorectal adenocarcinoma “stem cells”.
8.Association of Ki67 with raised transaminases in hepatocellular carcinoma.
Phaik-Leng Cheah ; Lai-Meng Looi ; Abdul Rahman Nazarina ; Kein-Seong Mun ; Khean-Lee Goh
The Malaysian journal of pathology 2008;30(2):103-7
Transaminase enzymes, alanine (ALT) and aspartate transaminase (AST), have been reported to be raised and implicated to have prognostic value in hepatocellular carcinoma (HCC). Ki67, a marker of cellular proliferative activity, has also been noted to be increased in HCC. A study was conducted at the Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur to determine the possible association of proliferative activity, as determined by Ki67, with the transaminase enzymes. 31 cases of histologically diagnosed HCC who underwent tumour resection were retrieved from departmental archives. The patients' ages ranged between 40 to 79 years with a mean of 58.3 years. There was a male preponderance with M:F = 2.9:1. Ethnic Chinese formed 83.9% of the cases. 4 microm sections, cut from the formalin-fixed, paraffin-embedded tumour tissue block of each case, were immunohistochemically stained with Ki67 (DAKO monoclonal MIB-1) using the commercial DakoCytomation EnVision+System-HRP kit. The latest ALT and AST levels, assayed within 7 days prior to tumour resection, were retrieved from the patients' case records. 24 (77.4%) HCC demonstrated elevation of either ALT and/or AST. 27 (87.1%) HCC were immunopositive for Ki67. Ki67 immunoexpression was significantly correlated with raised transaminases (p<0.05). Hypothetically, the mechanism by which this phenomenon may occur may simply be release of transaminases due to destruction of hepatocytes by the cancer. Thus rising levels of the transaminases could signal a more rapid growth of the tumour and these routinely performed tests can be of prognostic value in management of HCC patients.
Aspartate aminotransferase assay
;
Alanine aminotransferase measurement
;
Primary carcinoma of the liver cells
;
prognostic
;
Excision
9.CD44 expression and axillary lymph node metastasis in infiltrating ductal carcinoma of the breast.
Lai Meng Looi ; Phaik Leng Cheah ; Wenran Zhao ; Min-Hwei Ng ; Cheng Har Yip
The Malaysian journal of pathology 2006;28(2):83-6
Metastasising ability connotes one of the most important life-threatening properties of malignant neoplasms. Recent studies indicate that CD44 proteins, multifunctional cell adhesion molecules which contribute to "homing" of lymphocytes to lymph nodes as well as cell-cell and cell-matrix interactions, are potential markers of tumour progression. However, whether CD44 expression by human tumours contribute to increased metastatic risk remains controversial. In an attempt to clarify its role in breast cancer, we have investigated the correlation between CD44 expression by breast carcinoma and the presence of axillary lymph node metastases. CD44 expression was detected using a standard immunoperoxidase method on formalin-fixed, paraffin-embedded, primary infiltrating ductal breast carcinoma tissues taken from 60 female patients who underwent mastectomy with axillary node clearance. Tumours were graded according to the modified Bloom and Richardson criteria. 62% of patients had histologically-proven lymph node metastasis. 40% of primary cancers exhibited cytoplasmic membrane immunopositivity for CD44. 46% of primary tumours which have metastasied to axillary lymph nodes were CD44 positive whereas 30% of tumours which have not metastasised expressed CD44. CD44 positivity was expressed by 20% of grade 1, 31% grade 2 and 58% grade 3 tumours. Our results suggest that CD44 may have a role in the progression of breast cancer and emphasise the need to investigate its interaction with other mechanisms of cancer advancement.
Antigens, CD44
;
lymph nodes
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Neoplasm Metastasis
;
Cells
;
Malignant neoplasm of breast
10.Proliferating cell nuclear antigen (PCNA) activity in hepatocellular carcinoma, benign peri-neoplastic and normal liver.
Kein-Seong Mun ; Phaik-Leng Cheah ; Nurul Bahiyah Baharudin ; Lai-Meng Looi
The Malaysian journal of pathology 2006;28(2):73-7
Hepatocellular carcinoma (HCC) is among the ten most common cancers in Malaysian males. As cellular proliferation is an important feature of malignant transformation, we studied the proliferation pattern of normal and benign perineoplastic liver versus hepatocellular carcinoma in an attempt to further understand the tumour transformation process. 39 HCC (21 with accompanying and 18 without cirrhosis) histologically diagnosed at the Department of Pathology, University of Malaya Medical Centre between January 1992 and December 2003 were immunohistochemically studied using a monoclonal antibody to PCNA (Clone PC10: Dako). 20 livers from cases who had succumbed to traumatic injuries served as normal liver controls (NL). PCNA labeling index (PCNA-LI) was determined by counting the number of immunopositive cells in 1000 contiguous HCC, benign cirrhotic perineoplastic liver (BLC), benign perineoplastic non-cirrhotic (BLNC) and NL cells and conversion to a percentage. The PCNA-LI was also expressed as Ojanguren et al's grades. PCNA was expressed in 10% NL, 38.9% BLNC, 76.2% BLC and 71.8% HCC with BLNC, BLC and HCC showing significantly increased (p < 0.05) number of cases which expressed PCNA compared with NL. The number of BLC which expressed PCNA was also significantly increased compared with BLNC. PCNA-LI ranged from 0-2.0% (mean = 0.2%) in NL, 0-2.0% (mean = 0.3%) in BLNC, 0-3.6% (mean = 0.7%) in BLC and 0-53.8% (mean = 7.6%) in HCC with PCNA-LI significantly increased (p < 0.05) only in HCC compared with BLC, BLNC and NL. Accordingly, all NL, BLC and BLNC showed minimal (<5% cells being immunopositive) immunoreactivity on Ojanguren et al's grading system and only HCC demonstrated immunoreactivity which ranged up to grade 3 (75% of cells). From this study, there appears to be a generally increasing trend of proliferative activity from NL to BLNC to BLC and HCC. Nonetheless, BLNC and BLC, like NL, retained low PCNA-LI and only HCC had a significantly increased PCNA-LI compared with the benign categories. This is probably related to the malignant nature of HCC and may reflect the uncontrolled proliferation of the neoplastic hepatocytes.
Proliferating Cell Nuclear Antigen
;
Benign
;
Lithium
;
Liver
;
Primary carcinoma of the liver cells