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Occult primary breast carcinoma presented as an axillary mass: A Diagnostic Challenge

Wong YP, Tan GC, Muhammad R, Rajadurai P

Malays J Pathol, 2020 Apr;42(1):151-155.
PMID: 32342946

INTRODUCTION: Occult primary breast carcinoma (OBC) manifesting as axillary nodal metastasis without an identifiable breast primary is exceptionally rare. It continues to pose a diagnostic challenge to pathologists. Here, we report a case of OBC with emphasis on the usefulness of immunohistochemistry to determine the primary site of tumour.
CASE REPORT: A 58-year-old female presented with a 3-cm painless right axillary mass. Extensive radiological investigations that include mammography, ultrasonography of the breasts and positron emission tomography (PET) scan failed to conclude the primary site of the tumour. Histological examination of the lymph node revealed loosely cohesive sheets of poorly differentiated malignant cells, without discernible glandular or squamous differentiation. Immunohistochemically, the malignant cells exhibited diffuse immunoreactivity toward pan-cytokeratin and CK7, while leukocyte common antigen, S100 and CK20 were negative. A second panel of immunomarkers was carried out. The malignant cells expressed breast-specific markers (GATA-3, GCDFP-15 and mammaglobin), and were negative for ER, PR and TTF-1 immunohistochemistry. A diagnosis of OBC was rendered.
DISCUSSION: Breast primary must always be considered in the differential diagnosis in patients with sole presentation of axillary lymphadenopathy. The breast-specific immunomarkers play a pivotal role in the diagnosis of ER, PR-negative occult breast cancer.
Fulltext First isolation of Burkholderia tropica from a neonatal patient successfully treated with imipenem

Deris ZZ, Van Rostenberghe H, Habsah H, Noraida R, Tan GC, Chan YY, et al.

Int J Infect Dis, 2010 Jan;14(1):e73-4.
PMID: 19482535 DOI: 10.1016/j.ijid.2009.03.005

We report the first case of a human Burkholderia tropica infection. The patient was a premature neonate who had necrotizing enterocolitis with bowel perforation requiring surgical intervention. The stoma care and difficulties in feeding were a chronic problem. At the age of almost 4 months he developed septicemia due to B. tropica. Three consecutive blood cultures grew this organism. The organism was cleared from the blood after a course of imipenem and resolution of post-operative ileus. Our case suggests that environmental and plant pathogens can cause human infection especially in those in an immunocompromised condition.
Large retrosternal parathyroid carcinoma with primary hyperparathyroidism

Tan GC, Shiran MS, Swaminathan M, Phang KS, Rohaizak M

Asian J Surg, 2007 Oct;30(4):286-9.
PMID: 17962134

Parathyroid carcinoma is an uncommon cause of parathyroid hormone (PTH)-dependent hypercalcaemia, accounting for less than 1% of all cases of hyperparathyroidism. Parathyroid carcinoma is an indolent tumour with rather low malignant potential. Consideration of parathyroid carcinoma in the differential diagnosis of hypercalcaemic disorders is important because the morbidity and mortality are substantial and the best prognosis is associated with early recognition and surgical resection. Clinical indicators favouring parathyroid carcinoma over benign disease include markedly raised serum calcium levels, PTH and alkaline phosphatase. A palpable neck mass with both kidney and skeletal manifestations also give a high index of suspicion of parathyroid carcinoma. Histopathology alone is not sufficient to diagnose parathyroid cancer; it has to be correlated with the clinical findings. The initial and most effective treatment for parathyroid carcinoma is complete resection of the primary lesion, and repeated operations for recurrence are useful. The prognosis of parathyroid carcinomas is quite variable; 5-year survival rates vary from 40% to 86%, while the 10-year survival rate is approximately 49%. We report a case of parathyroid carcinoma occurring in a 55-year-old woman who presented with bone pain and hypercalcaemia.
Alveolar rhabdomyosarcoma of the left hand with bilateral breast metastases in an adolescent female

Tan GC, Shiran MS, Hayati AR, Sharifah NA, Nuru AS, Rohaizak M

J Chin Med Assoc, 2008 Dec;71(12):639-42.
PMID: 19114329

Rhabdomyosarcoma is a common extramammary malignancy in pediatric age groups, but it rarely metastasizes to the breast. Breast rhabdomyosarcomas are commonly metastatic, with possible primary locations at the head and neck, trunk, extremities, retroperitoneum and perianal region. We report a case of primary alveolar rhabdomyosarcoma of the upper extremities in a 17-year-old adolescent female who presented with bilateral lower limb weakness and bilateral breast lumps.
Collision tumor of the ovary: Fibroma and mature cystic teratoma

Tan GC, Chandramaya SF, Noordin A, S Tay PY

Indian J Pathol Microbiol, 2021 1 13;64(1):171-173.
PMID: 33433434 DOI: 10.4103/IJPM.IJPM_670_19

Collision tumor consists of two tumors occurring in the same organ without intermixture of the two cell types. The most common type of collision tumor in ovary is between teratoma and surface epithelial tumor. A 38-year-old woman presented with complained of lower abdominal pain and tightness, and a solid partially cystic left ovarian mass with minimal ascites was detected. Left salpingo-oophorectomy was performed. The ovarian mass measured 15 × 12 × 7 cm with a pedunculated mass on its surface which measured 6 × 2.5 × 2.5 cm. Histologically, it was a collision tumor of fibroma and mature cystic teratoma. Fibroma becomes more edematous as their size increases, which is frequently accompanied by the escape of increasing quantities of fluid from the tumor surfaces. Ascites is often detected when the fibroma is more than a diameter of 10 cm. It is important to identify the different components of a collision tumor for proper management.
Fulltext Evaluation of DNA and RNA extraction methods

Edwin Shiaw CS, Shiran MS, Cheah YK, Tan GC, Sabariah AR

Med J Malaysia, 2010 Jun;65(2):133-7.
PMID: 23756798 MyJurnal

This study was done to evaluate various DNA and RNA extractions from archival FFPE tissues. A total of 30 FFPE blocks from the years of 2004 to 2006 were assessed with each modified and adapted method. Extraction protocols evaluated include the modified enzymatic extraction method (Method A), Chelex-100 extraction method (Method B), heat-induced retrieval in alkaline solution extraction method (Methods C and D) and one commercial FFPE DNA Extraction kit (Qiagen, Crawley, UK). For RNA extraction, 2 extraction protocols were evaluated including the enzymatic extraction method (Method 1), and Chelex-100 RNA extraction method (Method 2). Results show that the modified enzymatic extraction method (Method A) is an efficient DNA extraction protocol, while for RNA extraction, the enzymatic method (Method 1) and the Chelex-100 RNA extraction method (Method 2) are equally efficient RNA extraction protocols.
Investigation on solution-to-gel characteristic of thermosensitive and mucoadhesive biopolymers for the development of moxifloxacin-loaded sustained release periodontal in situ gels

Sheshala R, Quah SY, Tan GC, Meka VS, Jnanendrappa N, Sahu PS

Drug Deliv Transl Res, 2019 04;9(2):434-443.
PMID: 29392681 DOI: 10.1007/s13346-018-0488-6

The objectives of present research were to develop and characterize thermosensitive and mucoadhesive polymer-based sustained release moxifloxacin in situ gels for the treatment of periodontal diseases. Poloxamer- and chitosan-based in situ gels are in liquid form at room temperature and transform into gel once administered into periodontal pocket due to raise in temperature to 37 °C. Besides solution-to-gel characteristic of polymers, their mucoadhesive nature aids the gel to adhere to mucosa in periodontal pocket for prolonged time and releases the drug in sustained manner. These formulations were prepared using cold method and evaluated for pH, solution-gel temperature, syringeability and viscosity. In vitro drug release studies were conducted using dialysis membrane at 37 °C and 50 rpm. Antimicrobial studies carried out against Aggregatibacter actinomycetemcomitans (A.A.) and Streptococcus mutans (S. Mutans) using agar cup-plate method. The prepared formulations were clear and pH was at 7.01-7.40. The viscosity of formulations was found to be satisfactory. Among the all, formulations comprising of 21% poloxamer 407 and 2% poloxamer 188 (P5) and in combination with 0.5% HPMC (P6) as well as 2% chitosan and 70% β-glycerophosphate (C6) demonstrated an ideal gelation temperature (33-37 °C) and sustained the drug release for 8 h. Formulations P6 and C6 showed promising antimicrobial efficacy with zone of inhibition of 27 mm for A.A. and 55 mm for S. Mutans. The developed sustained release in situ gel formulations could enhance patient's compliance by reducing the dosing frequency and also act as an alternative treatment to curb periodontitis.
Fulltext SARS-CoV-2 Infection in Pregnancy: Placental Histomorphological Patterns, Disease Severity and Perinatal Outcomes

Wong YP, Tan GC, Omar SZ, Mustangin M, Singh Y, Salker MS, et al.

Int J Environ Res Public Health, 2022 Aug 03;19(15).
PMID: 35954874 DOI: 10.3390/ijerph19159517

The association between maternal COVID-19 infection, placental histomorphology and perinatal outcomes is uncertain. The published studies on how placental structure is affected after SARS-CoV-2 virus in COVID-19-infected pregnant women are lacking. We investigated the effects of maternal SARS-CoV-2 infection on placental histomorphology and pregnancy outcomes. A retrospective cohort study on 47 pregnant women with confirmed SARS-CoV-2 infection, matched with non-infected controls, was conducted. Relevant clinicopathological data and primary birth outcomes were recorded. Histomorphology and SARS-CoV-2 immunohistochemistry analyses of placental tissues were performed. Only 1 of 47 cases showed SARS-CoV-2 immunoreactivity in the syncytiotrophoblasts. Histologically, decidual vasculopathy (n = 22/47, p = 0.004), maternal vascular thrombosis (n = 9/47, p = 0.015) and chronic histiocytic intervillositis (n = 10/47, p = 0.027) were significantly higher in the COVID-19-infected placentas when compared to the control group. Maternal vascular thrombosis was a significant feature in the active COVID-19 group. A significant lower gestational age (p < 0.001)) at delivery and a higher caesarean section rate (p = 0.007) were observed in the active SARS-CoV-2-infected cases, resulting in a significant lower fetal-placental weight ratio (p = 0.022) and poorer Apgar score (p < 0.001). Notably, active (p = 0.027), symptomatic (p = 0.039), severe-critical (p = 0.002) maternal COVID-19 infection and placental inflammation (p = 0.011) were associated with an increased risk of preterm delivery. Altered placental villous maturation and severe-critical maternal COVID-19 infection were associated with an elevated risk of poor Apgar scores at birth (p = 0.018) and maternal mortality (p = 0.023), respectively.
Fulltext Massive lower gastrointestinal bleeding attributable to heavy whipworm infection and Salmonella typhi co-infection: a case report

Nimir AR, Aziz MS, Tan GC, Shaker AR

Cases J, 2009;2:8285.
PMID: 19918413 DOI: 10.4076/1757-1626-2-8285

Massive lower gastrointestinal bleeding due to trichuriasis and/or typhoid fever is rarely reported. We reported a case of a 29-year-old male presented with per rectal bleeding, diarrhea, generalized abdominal pain and fever for two weeks. After diagnosis suspicion, emergency exploratory laparotomy was performed, where resection of the ulcerated part of the caecum and terminal ileum was performed. Microscopically analysis, diagnosed heavy infestation with Trichuris trichiura. It was complicated with Salmonella typhi infection confirmed later from the blood culture result.
Fulltext Editorial: Research Model Innovations in Advancing Neonatal Care

Cheah FC, Tan GC, Shi Y

Front Pediatr, 2021;9:711409.
PMID: 34222156 DOI: 10.3389/fped.2021.711409
Distribution of HPV genotypes in cervical cancer in multi- ethnic Malaysia

Hamzi Abdul Raub S, Isa NM, Zailani HA, Omar B, Abdullah MF, Mohd Amin WA, et al.

Asian Pac J Cancer Prev, 2014;15(2):651-6.
PMID: 24568473

BACKGROUND: Cervical cancer is the third commonest type of cancer among women in Malaysia. Our aim was to determine the distribution of human papilloma virus (HPV) genotypes in cervical cancer in our multi-ethnic population.
MATERIALS AND METHODS: This was a multicentre study with a total of 280 cases of cervical cancer from 4 referral centres in Malaysia, studied using real-time polymerase chain reaction (qPCR) detection of 12 high risk-HPV genotypes.
RESULTS: Overall HPV was detected in 92.5% of cases, in 95.9% of squamous cell carcinomas and 84.3%of adenocarcinomas. The five most prevalent high-risk HPV genotypes were HPV 16 (68.2%), 18 (40%), 58 (10.7%), 33 (10.4%) and 52 (10.4%). Multiple HPV infections were more prevalent (55.7%) than single HPV infections (36.8%). The percentage of HPV positive cases in Chinese, Malays and Indians were 95.5%, 91.9% and 80.0%, respectively. HPV 16 and 18 genotypes were the commonest in all ethnic groups. We found that the percentage of HPV 16 infection was significantly higher in Chinese (75.9%) compared to Malays (63.7%) and Indians (52.0%) (p<0.05), while HPV 18 was significantly higher in Malays (52.6%) compared to Chinese (25.0%) and Indians (28%) (p<0.05). Meanwhile, HPV 33 (17.9%) and 52 (15.2%) were also more commonly detected in the Chinese (p<0.05).
CONCLUSIONS: This study showed that the distribution of HPV genotype in Malaysia is similar to other Asian countries. Importantly, we found that different ethnic groups in Malaysia have different HPV genotype infection rates, which is a point to consider during the implementation of HPV vaccination.
C-erbB-2 onco-protein expression in breast cancer: relationship to tumour characteristics and short-term survival in Universiti Kebansaan Malaysia Medical Centre

Sharifah NA, Lee BR, Clarence-Ko CH, Tan GC, Shiran MS, Naqiyah I, et al.

Asian Pac J Cancer Prev, 2008 Oct-Dec;9(4):663-70.
PMID: 19271345

Breast cancer is the commonest cancer affecting females in Malaysia, contributing 31% of all newly diagnosed cases amongst Malaysian women. The present retrospective cohort study evaluated the relationship between cerbB- 2 onco-protein overexpression with various tumour characteristics and survival rate of breast cancer patients treated at the Universiti Kebangsaan Malaysia Medical Centre (UKMMC) between 1996-2000. CerbB- 2 oncoprotein overexpression was determined by immunohistochemistry (IHC) and tumors showing 2+ positivity were verified by Fluorescence In Situ Hybridization (FISH). One hundred and seventy two patients were eligible for the study with a short-term follow-up (median) of 5.1 years. C-erbB-2 oncoprotein overexpression correlated with lymph node positivity, oestrogen receptor (ER) and progesterone receptor (PR) negativity. Univariate analyses showed shorter disease free survival (DFS) and overall survival (OS) in patients with cerbB- 2 oncoprotein overexpression, Malay ethnicity, higher tumour grade, lymph node positivity, ER and PR negativity. In a subgroup of patients with c-erbB-2 oncoprotein overexpression, a shorter OS was observed in those with lymph node positivity, ER and PR negativity. In multivariate prognostic analysis, lymph node status, ER status and tumour grading were the strongest independent prognostic factors for both OS and DFS. However, c-erbB-2 status was not a significantly independent prognostic factor, even in subsets with lymph node positive or negative group. C-erbB-2 oncoprotein overexpression correlated well with lymph node status, ER and PR. Shorter OS and DFS were significantly observed in patients with c-erbB-2 oncoprotein overexpression. Lymph node status, ER status and tumour grading were the only three independent prognostic factors for OS and DFS in this study. Although c-erbB-2 expression is obviously important from a biological standpoint, multivariate analysis showed that it is not an independent prognostic indicator in breast carcinoma in the local population.
Fulltext Human telomerase reverse transcriptase expression in ovarian tumors

Maraei AA, Hatta AZ, Shiran MS, Tan GC

Indian J Pathol Microbiol, 2012 Apr-Jun;55(2):187-91.
PMID: 22771641 DOI: 10.4103/0377-4929.97865

Ovarian cancer is the 6 th most common cancer among women. In ovarian tumors, the borderline category is not well defined due to the difficulty in assessing stromal invasion. The World Health Organization (WHO) defined it as tumor that lacks obvious invasion of the stroma with mitotic activity and nuclear abnormalities intermediate between clearly benign and unquestionably malignant. Telomerase is expressed in many human cancers and is hence a potential biomarker for cancer. Immunohistochemical study of anti-human telomerase enzyme reverse transcriptase (hTERT) antibody allows direct visualization of its expression. The aim of this study was to determine the expression of hTERT and serum CA-125 level in ovarian epithelial tumors, and their ability to distinguish borderline tumor from malignancy.
Fulltext An immunohistochemical study of Toll-like receptors 2 and 4 in placenta with and without infection

Hayati AR, Mohamed AE, Tan GC

Malays J Pathol, 2010 Jun;32(1):13-9.
PMID: 20614721 MyJurnal

The placenta constitutes a physical and immunological barrier against infectious agents. Toll-like receptors (TLRs) are essential components for the induction of innate immunity responses in different human tissues including the placenta. We investigated the expressions of TLR2 and TLR4 in the decidua and amniotic cells in non-inflamed placenta and placenta with infection.
Value of human amniotic epithelial cells in tissue engineering for cornea

Fatimah SS, Ng SL, Chua KH, Hayati AR, Tan AE, Tan GC

Hum. Cell, 2010 Nov;23(4):141-51.
PMID: 21166885 DOI: 10.1111/j.1749-0774.2010.00096.x

Human amniotic epithelial cells (hAECs) are potentially one of the key players in tissue engineering due to their easy availability. The aim of the present study was to develop an optimal isolation and transportation technique, as well as to determine the immunophenotype and epithelial gene expression of hAECs. Amnion was mechanically peeled off from the chorion and digested with trypsin-ethylenediaminetetraacetic acid. The isolated hAECs were cultured in medium containing 10 ng/mL epidermal growth factor until P4. The epithelial gene expression, cell surface antigen and protein expression of hAECs were analyzed by quantitative polymerase chain reaction, flow cytometry and immunocytochemistry. hAECs were also cultured in adipogenic, osteogenic and neurogenic induction media. The best cell yield of hAECs was seen in the digestion of 15 pieces of amnion (2 × 2 cm) and isolated 30 min after digestion with trypsin. F12:Dulbecco's modified eagle medium was the best medium for short term storage at 4 °C. hAECs expressed CD9, CD44, CD73 and CD90, and negligibly expressed CD31, CD34, CD45 and CD117. After serial passage, CK3, CK19 and involucrin gene expressions were upregulated, while p63, CK1 and CK14 gene expressions were downregulated. Sustained gene expressions of integrin β1 and CK18 were observed. At initial culture, these cells might have stem-like properties. However, they differentiated after serial passage. Nonetheless, hAECs have epithelial stem cell characteristics and have the potential to differentiate into corneal epithelial cells. Further investigations are still needed to elucidate the mechanism of differentiation involved and to optimize the culture condition for long term in vitro culture.
The stemness gene expression of cultured human amniotic epithelial cells in serial passages

Simat SF, Chua KH, Abdul Rahman H, Tan AE, Tan GC

Med J Malaysia, 2008 Jul;63 Suppl A:53-4.
PMID: 19024980

The aim of the study is to evaluate the stemness gene expression of cultured human amniotic epithelial cells (HAECs) in serial passages. HAECs obtained from human term placentae were cultured in F12:DMEM(1:1) + 10% FBS +10ng/ml EGF in serial passages (P0, P1, P2 and P4). Quantitative RT-PCR was used to assess the gene expression analysis. The results showed that cultured HAECs expressed and downregulated the stemness genes expression for Oct-4, Sox-2, Nanog3, FGF4, Rex-1, FZD-9, BST-1 ABCG2. However, vimentin and nestin gene expression were upregulated. The results suggested that cultured HAECs may have pluripotent and multipotent properties.
LBOS 02-06 HISTOPATHOLOGICAL-SPECIFIC MUTATION SPECTRUM OF ALDOSTERONE-PRODUCING ADENOMAS

Azizan E, Sukor N, Kamaruddin NA, Jamal AR, Ceral J, Solar M, et al.

J Hypertens, 2016 Sep;34 Suppl 1 - ISH 2016 Abstract Book:e550.
PMID: 27754305

Aldosterone-producing adenoma (APA) is a common curable cause of hypertension. Somatic mutations in five genes (KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1) have been found to cause the excess aldosterone production of two thirds of APAs [1-4]. KCNJ5 mutant APAs, the most common and largest, had explicit genotype-phenotype relationship - a low protein expression of KCNJ5 relative to their peritumoural zona glomerulosa (ZG) and a zona fasciculata-like composition [5-6]. Conversely for the other genes, controversy arises on whether they have the opposite cell phenotype [4,7-8]. This prospective study aim to to characterize the histopathological-specific mutation spectrum of APAs.
Fulltext The Role of Breast Cancer Stem Cell-Related Biomarkers as Prognostic Factors

Ko CCH, Chia WK, Selvarajah GT, Cheah YK, Wong YP, Tan GC

Diagnostics (Basel), 2020 Sep 19;10(9).
PMID: 32961774 DOI: 10.3390/diagnostics10090721

Breast cancer is one of the leading causes of cancer-related deaths in women worldwide, and its incidence is on the rise. A small fraction of cancer stem cells was identified within the tumour bulk, which are regarded as cancer-initiating cells, possess self-renewal and propagation potential, and a key driver for tumour heterogeneity and disease progression. Cancer heterogeneity reduces the overall efficacy of chemotherapy and contributes to treatment failure and relapse. The cell-surface and subcellular biomarkers related to breast cancer stem cell (BCSC) phenotypes are increasingly being recognised. These biomarkers are useful for the isolation of BCSCs and can serve as potential therapeutic targets and prognostic tools to monitor treatment responses. Recently, the role of noncoding microRNAs (miRNAs) has extensively been explored as novel biomarker molecules for breast cancer diagnosis and prognosis with high specificity and sensitivity. An in-depth understanding of the biological roles of miRNA in breast carcinogenesis provides insights into the pathways of cancer development and its utility for disease prognostication. This review gives an overview of stem cells, highlights the biomarkers expressed in BCSCs and describes their potential role as prognostic indicators.
Virtual meeting in pathology: Time to adapt to the new-norm

Wong YP, Tan GC

Malays J Pathol, 2021 Apr;43(1):1.
PMID: 33903298

No abstract available.
Nasal Plasmablastic Lymphoma in an HIV-Negative Immunocompetent Patient

Shakri NM, Husain S, Zahedi FD, Tan GC

Medeni Med J, 2020;35(1):71-74.
PMID: 32733753 DOI: 10.5222/MMJ.2020.45389

Plasmablastic lymphoma (PBL) is a rare and aggressive variant of diffuse large B-cell lymphoma predominantly in oral cavities of human immunodeficiency virus (HIV)-positive male patients or immunosuppressive hosts. Limited number of reports on HIV-negative PBL in immunocompetent patients are available in the literature. We reported an unusual case of sinonasal PBL which occurred in an HIV-negative and immunocompetent female patient. She underwent endoscopic removal of the tumor and completed 6 cycles of chemotherapy (hyperfractionated-CVAD). Any finding in favour of tumour recurrence was not observed in positron-emission tomography scan (PET-scan) performed 18 months after the treatment.

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