Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a systemic disease involving nodal and extranodal tissues. We report a 48-year-old female with recurrent nasal obstruction due to polypoidal masses involving the nasal sinuses, turbinates and septum bilaterally, and lumps in the right infra-orbital region and region of the right lacrimal sac. A 4 cm right upper neck mass was also noted, which was initially diagnosed as histiocytic lymphoma. Histopathology of the nasal and infraorbital lesions revealed fibro-inflammatory masses containing histiocytic cells with large vesicular nuclei and abundant foamy cytoplasm exhibiting emperipolesis and lymphophagocytosis, admixed with scattered plasma cells and lymphocytes. These histiocytes revealed immunohistochemical positivity for S-100 protein and CD68, but were negative for CDla. The findings supported a diagnosis of RDD. This report serves to remind pathologists and clinicians of the extranodal manifestations of RDD and its potential confusion with lymphomas.
Neuroendocrine carcinomas of the breast are uncommon tumors known to occur in the elderly. While focal neuroendocrine differentiation may be noted in many ductal and lobular carcinomas, the term neuroendocrine carcinoma is to be applied when more than 50% of the tumor shows such differentiation. This case report details the cytological features of a neuroendocrine carcinoma that was encountered in our hospital. The fine needle aspiration (FNA) smears showed discohesive polygonal cells with abundant cytoplasm, many of which contained eosinophilic granules located at one pole. Histology of the mastectomy and axillary lymph nodes specimen from this patient showed features of neuroendocrine carcinoma--solid type, with metastasis, confirmed with immunohistochemistry. The patient is disease free seven months after surgery. This case highlights the need to closely observe cytological details to identify this rare tumor that may otherwise appear to be invasive duct carcinoma--not otherwise specified on FNA. The implications of diagnosing neuroendocrine differentiation for prognosis and management are also discussed.
We report a case of bone marrow necrosis preceding infantile acute lymphoblastic leukaemia (ALL). Bone marrow necrosis is a rare antemortem event and has been known to be present in many conditions, notably in haematological malignancies like acute lymphoblastic leukaemia. This case was a 6-month-old Chinese boy who was referred to Hospital Universiti Kebangsaan Malaysia for further investigation of pancytopaenia, high-grade fever, bloody diarrhoea and petechial rashes for one week. His first bone marrow aspirate revealed bone marrow necrosis. His clinical condition improved after ten days. However, his full blood picture then revealed the presence of 5% blast cells. His subsequent marrow 2 weeks later revealed acute lymphoblastic leukaemia (FAB-L1) and immunophenotyping showed precursor B acute lymphoblastic leukaemia-null type. He was started on United Kingdom Acute Lymphoblastic leukaemia (UK ALL) Infantile Leukaemia protocol, however, he defaulted treatment after 3 days. Mode of presentation, mechanism of disease and laboratory investigations and outline of treatment will be discussed.
Transient abnormal myelopoeisis (TAM) is a haematological phenomenon commonly seen in newborns with Down syndrome. Although the majority show spontaneous resolution, this condition should not be dismissed too readily as there have been associated fatalities. Furthermore, even for those who do show spontaneous resolution, a significant percentage will develop acute megakaryoblastic leukaemia within the next few years of life. We report a series of four patients with TAM who presented with hepatosplenomegaly and leucocytosis detected on preliminary investigations.
The Nipah virus outbreak in Malaysia (September 1998 to May 1999) resulted in 265 cases of acute encephalitis with 105 deaths, and near collapse of the billion-dollar pig-farming industry. Because it was initially attributed to Japanese encephalitis, early control measures were ineffective, and the outbreak spread to other parts of Malaysia and nearby Singapore. The isolation of the novel aetiological agent, the Nipah virus (NiV), from the cerebrospinal fluid of an outbreak victim was the turning point which led to outbreak control 2 months later. Together with the Hendra virus, NiV is now recognised as a new genus, Henipavirus (Hendra + Nipah), in the Paramyxoviridae family. Efforts of the local and international scientific community have since elucidated the epidemiology, clinico-pathophysiology and pathogenesis of this new disease. Humans contracted the infection from close contact with infected pigs, and formed the basis for pig-culling that eventually stopped the outbreak. NiV targeted medium-sized and small blood vessels resulting in endothelial multinucleated syncytia and fibrinoid necrosis. Autopsies revealed disseminated cerebral microinfarctions resulting from vasculitis-induced thrombosis and direct neuronal involvement. The discovery of NiV in the urine and saliva of Malaysian Island flying foxes (Pteropus hypomelanus and Petropus vampyrus) implicated these as natural reservoir hosts of NiV. It is probable that initial transmission of NiV from bats to pigs occurred in late 1997/early 1998 through contamination of pig swill by bat excretions, as a result of migration of these forest fruitbats to cultivated orchards and pig-farms, driven by fruiting failure of forest trees during the El Nino-related drought and anthropogenic fires in Indonesia in 1997-1998. This outbreak emphasizes the need for sharing information of any unusual illnesses in animals and humans, an open-minded approach and close collaboration and co-ordination between the medical profession, veterinarians and wildlife specialists in the investigation of such illnesses. Environmental mismanagement (such as deforestation and haze) has far-reaching effects, including encroachment of wildlife into human habitats and the introduction of zoonotic infections into domestic animals and humans.
Hepatitis B virus (HBV) is classified into eight genotypes (A to H). In this study, three genotyping methods were compared for their sensitivity and accuracy, namely PCR-RFLP on the S region, PCR-RFLP on the pre-S region and nested PCR with type specific primers. Sixty HBV samples from infected sera were genotyped. The nested PCR with type specific primers was found to be the most sensitive and produced substantial numbers of co-infections by genotypes B and C. The sensitivities for both PCR-RFLP methods were lower and did not reveal co-infections. Generally, the three methods produced consistent genotyping results in samples infected by single genotypes but for co-infections by genotypes B and C, the two PCR-RFLP methods yielded only single genotypic results. For the cases of single genotypic infections, genotypes ascertained by sequencing were in concordance across all three methods. However, when co-infections occurred, PCR analysis on clones revealed only single genotypic infections.
All known field isolates of enterovirus 71 (EV71) can be divided into three distinct genogroups (A, B, C) and 10 subgenogroups (A, B1-5, C1-4) based on VP1 gene sequences. We examined VP1 gene sequences of 10, 12 and 11 EV71 strains isolated in peninsular Malaysia during the outbreaks of hand, foot and mouth disease in 1997, 2000 and 2005 respectively. Four EV71 strains isolated in the hand, foot and mouth disease outbreak of 2006 in Sarawak (Malaysian Borneo) were included to describe their genetic relationship. Four subgenogroups (C1, C2, B3 and B4) of EV71 co-circulated and caused the outbreak of hand, foot and mouth disease in peninsular Malaysia in 1997. Two subgenogroups (C1 and B4) were noted to cause the outbreak in 2000. In the 2005 outbreak, besides EV71 strains of subgenogroup C1, EV71 strains belonged to subgenogroup B5 were isolated but formed a cluster which was distinct from EV71 strains of the subgenogroup B5 isolated in 2003. The four EV71 strains isolated from clinical specimens of patients with hand, foot and mouth disease in the Sarawak outbreak in early 2006 also belonged to subgenogroup B5. Phylogenetic analysis of the VP1 gene sequences showed that the four Sarawak EV71 isolates belonged to the same cluster as the EV71 strains that were isolated in peninsular Malaysia as early as May 2005. The data suggested that the EV71 strains causing the outbreak in Sarawak could have originated from peninsular Malaysia.
Hepatocellular carcinoma (HCC) is the most common primary liver cancer and its diagnosis on routine stains is usually straightforward, except in some cases where there may be difficulty in distinguishing HCCs from metastatic carcinomas (MC) and cholangiocarcinomas (CC). Hepatocyte Paraffin 1 antibody (Hep Par 1) is a new monoclonal antibody which reacts with normal and neoplastic hepatocytes, and this study aims to determine its specificity and sensitivity in distinguishing hepatocellular carcinoma (HCC) from cholangiocarcinoma (CC) and metastatic carcinomas (MC). Hep Par 1 antibody was applied to 28 cases of HCC, 22 cases of MC from varying sites and 8 CCs, and produced a strong, diffuse, granular, cytoplasmic staining of all benign hepatocytes. 23 out of 28 cases of HCC showed heterogeneously positive staining for Hep Par 1 irrespective of their degree of differentiation, while 2 out of 8 cases of cholangiocarcinoma were positive for Hep Par 1, and all 22 cases of metastatic carcinoma were negative. The sensitivity and specificity of Hep Par 1 for HCC was 82.1% and 93.3% respectively; whereby the antibody was noted to show occasional false positivity in cases of cholangiocarcinoma and non-neoplastic bowel mucosa, while its variable staining in HCC produced false negative results in some small biopsies. Thus, Hep Par 1 should be used in a panel with other antibodies to obtain useful information in distinguishing HCC from CC and MC.
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.
Male-specific coliphages are often used as indicators of contamination by enteric viruses. These phages can be detected in water samples by plaque assays and by polymerase chain reaction. In this study, the M13 coliphage was used to develop a real-time PCR assay for the detection of male-specific DNA coliphages. The real-time PCR was found to have a reaction efficiency of 1.45 and detection limit of 10(-3) plaque forming units per reaction mix. Repeated amplification and melting curve analyses demonstrated high specificity and reproducibility of the real-time assay. Quantitative detection with the real-time PCR should allow rapid assessment of the level of viral contamination in water.
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.
Survivin is an inhibitor of apoptosis protein and regulates the cell cycle in the G2/M phase. Survivin is expressed during embryonic and fetal development, selectively over-expressed in common human cancers and completely down-regulated in normal adult tissue. This work was aimed at studying the expression of the survivin homologues and their subcellular distribution in fetal and normal adult tissues of rat. Survivin expression was evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of fetal and normal adult tissues of rat using the polyclonal serum SUR12A-CFI. This serum demonstrated intense positive survivin staining in adult kidney, ovary and oviduct, and a variable expression in different fetal organs, with particularly intense expression detected in the adrenal gland, liver, stomach, small intestine, colon, kidney and skin. In both fetal and adult tissues, the expression was predominantly cytoplasmic. It was concluded that survivin was abundantly and prominently expressed during fetal development in rat and that the polyclonal anti-human survivin antibody SUR12A-CFI is reactive with rat survivin.
This study was carried out to determine the role of p53 and p21 in the pathogenesis of prostatic adenocarcinoma and their association with tumour grade.
We report a case of clear cell "sugar" tumour of the lung (CCTL) occurring in a 26-year-old lady. The patient was asymptomatic and the lesion was picked up in the course of a pre-employment medical examination. A well-defined 5 cm nodule in the right lower lobe was detected on routine chest X-Ray. Microscopical examination of the coin lesion showed clear cells containing abundant diastase-sensitive intracytoplasmic glycogen, as demohstrated with periodic acid-Schiff stains. Tumour immunoreactivity for HMB-45 and non-reactivity for cytokeratin support the histological diagnosis. To our knowledge, this is the first reported case of CCTL in Malaysia.
Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haemopoietic stem cell disorder arising from somatic mutation of the X-linked PIG-A gene which leads to deficiency of the glycosylphosphatidylinositol (GP1) membrane anchor proteins such as CD 59 (MIRL: membrane inhibitor of reactive lysis) and CD 55 (DAF: decay accelerating factor). Allogeneic peripheral blood stem cell transplant (PBSCT) is a curative mode of treatment in symptomatic PNH patients. Assessment of donor chimerism for PBSCT can be performed by various methods including short tandem repeat loci (STR) and variable number of tandem repeats (VNTR). Flow cytometry, which is much cheaper and faster, also can be used to assess engraftment in patients with PNH. Engrafted patients will show the presence of CD 55 and CD 59 on their red cells and white cells. We describe here the usefulness of flow cytometry in the assessment of donor chimerism following allogeneic PBSCT, in a case of PNH.
Familial hypercholesterolaemia (FH) and Familial defective apolipoprotein B100 (FDB) are autosomal dominant inherited diseases of lipid metabolism caused by mutations in the low density lipoprotein (LDL) receptor and apolipoprotein B 100 genes. FH is clinically characterised by elevated concentrations of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C), presence of xanthomata and premature atherosclerosis. Both conditions are associated with coronary artery disease but may be clinically indistinguishable. Seventy-two (72) FH patients were diagnosed based on the Simon Broome's criteria. Mutational screening was performed by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). Positive mutations were subjected to DNA sequencing for confirmation of the mutation. We successfully amplified all exons in the LDL receptor and apo B100 genes. DGGE was performed in all exons of the LDL receptor (except for exons 4-3', 18 and promoter region) and apo B100 genes. We have identified four different mutations in the LDL receptor gene but no mutation was detected in the apo B 100 gene. The apo B100 gene mutation was not detected on DGGE screening as sequencing was not performed for negative cases on DGGE technique. To our knowledge, the C234S mutation (exon 5) is a novel mutation worldwide. The D69N mutation (exon 3) has been reported locally while the R385W (exon 9) and R716G (exon 15) mutations have not been reported locally. However, only 4 mutations have been identified among 14/72 patients (19.4%) in 39 FH families. Specificity (1-false positive) of this technique was 44.7% based on the fact that 42/76 (55.3%) samples with band shifts showed normal DNA sequencing results. A more sensitive method needs to be addressed in future studies in order to fully characterise the LDLR and apo B100 genes such as denaturing high performance liquid chromatography. In conclusion, we have developed the DNA analysis for FH patients using PCR-DGGE technique. DNA analysis plays an important role to characterise the type of mutations and forms an adjunct to clinical diagnosis.
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.
Edwardsiella tarda has recently been described as a member of the family Enterobacteriaceae. The genus Edwardsiella contains three species; E. hoshinae, E. ictaluri and E. tarda. Edwardsiella tarda is the only species which has been recognised as pathogenic to humans, especially in those with an underlying disease. The most common presentation is watery diarrhoea. Extra intestinal infections have been reported infrequently. Humans seem to be infected or colonised with Edwardsiella through ingestion or inoculation of a wound. This report is of a patient with multiple liver abscesses due to E. tarda who later developed bacterial peritonitis and septicaemic shock.
Catheterization of the umbilical artery has been a useful aid in the management of sick neonates for the past few decades. However, it is associated with various complications. Reported studies strongly suggest a significant role of intravascular catheterization in the development of aortic thrombi. Increase in thrombosis of large vessels is believed to be related to mechanical injury in the catheterized vessels, which provide direct exposure of blood to tissue factor (TF), the primary cellular initiator of the extrinsic coagulation pathway. This study was conducted to determine the levels of plasma TF, tissue factor pathway inhibitor (TFPI) and D-dimer (DD) in infants with umbilical arterial catheter (UAC)-associated thrombosis. Quantification of TF was carried out using an in-house sandwich ELISA, whereas TFPI and DD levels were measured with commercial immunoassay kits. Infants with UAC inserted were found to have significantly higher levels of plasma TF (p < 0.001) than baseline levels. However, there were no significantly elevated levels of TFPI or DD. Infants with UAC-associated thrombosis demonstrated a greater increase of TF level (median: 414.5 pg/mL; range: -76.0, 6667.0) than infants without UAC-associated thrombosis (105.0 pg/mL; -976.0, 9480.0; p = 0.009) following UAC insertion. Our findings indicate that quantification and monitoring of TF levels could predict thrombus formation in infants with indwelling UAC. Following umbilical arterial catheterisation, infants with an approximately 3-fold rise in plasma TF levels were most at risk of developing abdominal aorta thrombosis as confirmed by real-time abdominal ultrasonography.