Publications (8)16.85 Total impact

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    ABSTRACT: We investigated hypoxia and necrosis in high grade and invasive bladder cancer, and related this to prognosis. We performed a retrospective observational study of 98 primary cystectomy specimens scored for necrosis, and the hypoxia associated markers carbonic anhydrase IX, hypoxia-inducible factor 1 alpha and 2 alpha, and Bcl2/adenovirus EIB 19 kDa interacting protein 3. Tumor tissue array was used with cores taken from representative and perinecrotic tumor regions. Necrosis was scored on whole sections as absent, less than 5 mm (comedo) or more than 5 mm (gross). Of the 98 cases analyzed followup data were available on 91. Median followup was 22 months (IQR 8-35). Stage was T0/1 to T4 in 18, 20, 41 and 12 cases, respectively. The prevalence of necrosis in bladder cancer was high and it increased with stage (17%, 30%, 70% and 71% at stages T0/1 to T4, respectively). Necrosis was significantly associated with stage (p = 0.0001) and nodal status (p = 0.016). Hypoxia-inducible factor 1 alpha showed no association with stage, grade or nodal status. Hypoxia-inducible factor 1 alpha and carbonic anhydrase IX showed a significant association with necrosis, whereas hypoxia-inducible factor 2 alpha and Bcl2/adenovirus EIB 19 kDa interacting protein 3 did not. Stage (p <0.0001), necrosis (p <0.0001) and intense hypoxia-inducible factor 1 positivity (p = 0.048) were the only significant prognostic factors on univariate analysis. Stage (HR 3.29, 95% CI 1.80-6.04, p <0.001) and necrosis (HR 1.92, 95% CI 1.05-3.51, p = 0.04) were independent prognostic factors on multivariate analysis, while hypoxia-inducible factor 1 lost significance (HR 1.36, 95% CI 0.98-1.88, p = 0.07). Node status was only reported in 45% of cases. Necrosis (the presence and amount) in high grade and invasive bladder cancer is an independent prognostic risk factor.
    The Journal of Urology 09/2007; 178(2):677-82. DOI:10.1016/j.juro.2007.03.112 · 3.75 Impact Factor
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    ABSTRACT: To review the first year of a monthly urine cytology screening service, introduced to identify renal transplant patients at risk of polyoma virus nephropathy (PVN), at an early, potentially treatable, stage. Monthly urine samples (n = 392) were received from 97/108 transplant recipients in 2005. Of 56 patients with follow-up >6 months, 20% and 9% had significant (>10 decoy cells/cytospin) and non-significant positive cytology, respectively. The first positive urine samples occurred most commonly in the second and third month post-transplantation and patients with significantly positive samples had higher 3-month and 6-month serum creatinine levels than patients with negative urine cytology (p<0.01). Four patients with positive urine cytology had a subsequent positive plasma BK virus PCR; 3/97 patients had biopsy-proven PVN, all in the third month, 1-6 weeks after first positive urine samples. Significant PV viruria is common following renal transplantation with onset usually within the first 3 months. Viruria is associated with worse graft function at 3 and 6 months. The time between urine positivity and clinical PVN is short. More frequent early urine screening would be required to achieve clinical benefit.
    Journal of Clinical Pathology 08/2007; 60(8):927-30. DOI:10.1136/jcp.2006.042507 · 2.55 Impact Factor
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    T P Thamboo · R Sim · S-Y Tan · W-M Yap
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    ABSTRACT: Primary retroperitoneal mucinous cystadenocarcinomas (PRMCs) are rare. This is the first reported case in the literature in English of PRMC in a man. The 64-year-old man presented with a large retroperitoneal cystic tumour measuring 24 x 20 x 16 cm3, which was removed intact. Areas ranging from a benign mucinous cyst to borderline mucinous tumour to mucinous cystadenocarcinoma were observed on microscopy. Strong patchy staining for cytokeratins 7 and 20 and strong diffuse staining for MUC2 and MUC5AC core peptides, similar to staining patterns in ovarian mucinous tumours, were shown in the benign and atypical epithelium. Staining for CA19.9 and carcinoembryonic antigen was also shown by both components. The theory of its origin from the mucinous metaplasia of peritoneal (mesothelial) inclusion cysts, rather than from ectopic ovarian tissue or ovarian teratomas, is supported by the occurrence of such a tumour in a male patient.
    Journal of Clinical Pathology 07/2006; 59(6):655-7. DOI:10.1136/jcp.2005.030122 · 2.55 Impact Factor
  • Thomas P Thamboo · Leonard H-C Tan · Soo-Yong Tan
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    ABSTRACT: Bcl-x appears to have an antiapoptotic role in the epidermis. Little is known about the expression of Bcl-x in cutaneous adnexal structures and benign cutaneous adnexal tumors. Tissues from 31 cases of benign cutaneous adnexal tumors (five trichofolliculomas, five trichoepitheliomas, two sebaceous adenomas, five apocrine hidradenomas, five eccrine poromas, five eccrine spiradenomas, and four syringomas) were immunostained for Bcl-x. Strong staining for Bcl-x was seen in cells of the epidermal granular layer and inner root sheath of hair follicles. Sebaceous gland cells showed strong staining. Apocrine gland cells showed weak to moderate staining. No staining was seen in eccrine gland cells. The basaloid cells of trichofolliculomas and trichoepitheliomas showed no staining. In sebaceous adenomas, the sebaceous cells showed strong staining while the basaloid cells were negative. The cells of apocrine hidradenomas showed patchy weak staining. No staining was seen in eccrine poromas, eccrine spiradenomas, and syringomas. The degree of Bcl-x expression in cutaneous adnexal glandular structures appears to be related to their mode of secretion, being strongest in cells with apoptotic degradation of the entire cell (sebocytes). This pattern is recapitulated in the corresponding benign cutaneous adnexal tumors. Bcl-x may be useful in identifying cells with sebaceous differentiation in poorly differentiated adnexal tumors.
    Journal of Cutaneous Pathology 02/2006; 33(1):27-32. DOI:10.1111/j.0303-6987.2006.00411.x · 1.56 Impact Factor
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    T P Thamboo · A Wee
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    ABSTRACT: To determine the frequency and pattern of Hep Par 1 expression in cervical carcinomas of various histological types and to correlate expression with prognostic parameters. Twenty nine cervical carcinomas were analysed for tumour type, hepatoid and neuroendocrine differentiation, and vascular invasion. A semiquantitative analysis was performed for Hep Par 1, alpha fetoprotein, chromogranin, and synaptophysin immunoreactivity. Hep Par 1 expression was seen in seven of the 29 cervical carcinomas (three of seven adenocarcinomas, one of 17 squamous cell carcinomas, one of two adenocarcinomas with adenocarcinoma in situ, one of two adenocarcinomas in situ, and one of one large cell neuroendocrine carcinoma with adenocarcinoma in situ). Normal looking endocervical epithelium was also positive in one case. Cases expressing Hep Par 1, with or without neuroendocrine coexpression, were associated with a higher rate of vascular invasion and a worse prognosis. Three of the five cases expressing neuroendocrine markers also coexpressed Hep Par 1. Hep Par 1 expression in carcinoma of the cervix is not uncommon and is present in a variety of histological types. Expression of this marker appears to be associated with more aggressive biological behaviour and a worse prognosis. The uterine cervix is another site that may express Hep Par 1 and hence the use of this antibody in situations of diagnostic difficulty, especially involving lesions within the liver, have to be coupled with the knowledge of the range of tissues it may stain.
    Journal of Clinical Pathology 02/2004; 57(1):48-53. DOI:10.1136/jcp.57.1.48 · 2.55 Impact Factor
  • Pathology 08/2003; 35(4):351-353. DOI:10.1080/00313020307534 · 2.62 Impact Factor
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    T P Thamboo · M Salto-Tellez · K B Tan · B Nilsson · A Rajwanshi
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    ABSTRACT: To describe the cervical cytology diagnoses and cyto-histological correlation in the Department of Pathology, National University of Singapore in 1997 and to compare the data with international figures. A database search of all cervical cytology cases diagnosed in the department in 1997 as well as follow-up biopsies was carried out. The data was then critically analysed. 10,207 cases were reviewed. 96% of the cases had a diagnosis of "negative". Under 1% of cases were labelled as "inadequate". "Atypia" was diagnosed in 1% and dysplasia and/or malignancy was diagnosed in 1%. These figures correlate well with international data. Of the dysplasia cases, 78% were followed by biopsy. Of the high-grade dysplasia cases that were biopsied, 97% of the biopsy diagnoses were within the acceptable concordance range with the cytology diagnoses and in only 3% was there a significant discrepancy. Of the cases diagnosed as atypia, 39% were subsequently biopsied at the same institution as the next procedure and only one showed high grade dysplasia. A total of six cases showed a significant discrepancy between the cervical cytology result and the subsequent biopsy diagnosis and these were reviewed to elucidate the reasons for the discrepancies. The cervical cytology service is of a high diagnostic standard. A subset of patients is probably being prematurely biopsied and may benefit from having a repeat smear instead. Specific clinical protocols regarding subsequent therapy following cytology results and closer cyto-histological correlation are two main areas where the cytology service can be improved.
    Singapore medical journal 06/2003; 44(5):256-60. · 0.63 Impact Factor
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    ABSTRACT: Transthoracic fine-needle aspiration cytology (FNAC) is a useful tool for evaluating neoplastic and inflammatory lung nodules. In view of the relative paucity of published audit studies regionally, such a study was undertaken to assess the use of the technique in our centre. One hundred and fourteen FNACs were performed during 1997-1999. Immediate assessment for specimen adequacy was done. Diagnoses were correlated with clinical-pathological information and selective blind review performed. Cytologically, 65.8% of cases were malignant, 1.8% were atypical, 25.4% were inflammatory/non-malignant and 7% were inadequate. Cytological-histological tumour diagnostic concordance was 94.4%. Diagnostic sensitivity for malignancy: 93.4%, specificity: 95.8%, accuracy: 94%. Eight inadequate/ benign cases (7%) proved to be malignant with clinical-pathological follow-up. Tuberculosis was confirmed (acid-fast bacilli detected) in six cases (5.3%) and suggested in a further 10 cases (8.8%). The cytological review showed 96% concordance with the original benign/malignant diagnoses. Pneumothorax rate was 18%. FNAC is an accurate and safe method for the evaluation of lung nodules and it enables subclassification of bronchogenic carcinomas in the vast majority of cases. It is also useful for the diagnosis of tuberculous pulmonary nodules. Immediate assessment optimises specimen adequacy; inadequate/non-malignant smears in particular, need clinical correlation, close follow-up and re-biopsy, if necessary.
    Singapore medical journal 12/2002; 43(11):570-5. · 0.63 Impact Factor