Nuclear morphometry in columnar cell lesions of the breast: is it useful?

AIMS

To evaluate the nuclear morphometric features of breast columnar cell lesions (CCLs) observed on mammotome core biopsies, to determine if there are significant measurable differences between those with atypia and those without. Correlation with follow-up open excision specimens was made.

METHODS

Mammotome core biopsies performed on patients that contained CCLs were derived from the departmental case files. Histological material was reviewed and foci of CCLs demarcated for nuclear morphometric assessment, which was accomplished using an imaging system. Nuclear parameters studied were nuclear area and perimeter, circularity factor and feret's diameter. Statistical analysis used the GraphPad Prism software, with p<0.05 indicating significance.

RESULTS

On examination of core biopsies of 40 patients with CCLs, 8 lesions were benign, 4 showed atypical lobular hyperplasia, 8 showed CCLs with nuclear atypia, 19 disclosed atypical ductal hyperplasia (ADH) and 1 showed ductal carcinoma in situ (DCIS). The nuclear area, perimeter and feret's diameter of CCLs with atypia were significantly greater than those without (p = 0.04, 0.03 and 0.019, respectively), whereas no difference was observed in the circularity factor. Follow-up open excision biopsy specimens in 24 patients showed upgrading to DCIS in 40% of cases diagnosed initially with ADH on core biopsy compared with 20% of CCLs with atypia.

CONCLUSIONS

Nuclear morphometry in CCLs confirms nuclear size as the key parameter in the assessment of nuclear atypia. Whether it can be potentially used as an adjunctive tool depends on the establishment of appropriate cut-offs.

Metaplastic carcinoma of the breast: a clinicopathological review

BACKGROUND

Mammary metaplastic carcinoma encompasses epithelial-only carcinoma (high-grade adenosquamous carcinoma or pure squamous cell carcinoma), biphasic epithelial and sarcomatoid carcinoma and monophasic spindle cell carcinoma.

AIM

To evaluate the clinicopathological features of a large series of 34 metaplastic carcinomas.

METHODS

10 epithelial-only, 14 biphasic and 10 monophasic metaplastic carcinomas were assessed for nuclear grade, hormone receptor status, HER2/neu (cerbB2) oncogene expression, Ki-67 and p53, lymph node status and recurrence on follow-up.

RESULTS

Intermediate to high nuclear grade were assessed in most (33/34) tumours. Oestrogen and progesterone receptors were negative in 8 of 10 epithelial-only, all 14 biphasic, and 9 of 10 monophasic tumours, cerbB2 was negative in 7 of 10 epithelial-only, all 14 biphasic and 8 of 10 monophasic tumours. Ki-67 was found to be positive in 6 of 10 epithelial-only, 6 of 14 biphasic, and 7 of 10 monophasic tumours, whereas p53 was positive in 6 of 10 epithelial-only, 7 of 14 biphasic, and 8 of 10 monophasic tumours. Lymph node metastases were seen in 7 of 7 epithelial-only, 7 of 11 biphasic, and 3 of 7 monophasic tumours. Recurrences were seen in 4 of 7 epithelial-only, 8 of 9 biphasic, and 4 of 9 monophasic tumours.

CONCLUSIONS

All three subtypes of metaplastic carcinoma are known to behave aggressively, and should be differentiated from the low-grade fibromatosis-like metaplastic carcinoma, which does not metastasize. Oncological treatment options may be limited by the frequently negative status of hormonal receptor and cerbB2.

2005 Galloway Memorial Lecture: Breast phyllodes tumours--morphology and beyond

OBJECTIVES

The aims of this study were to evaluate the predictive role of morphology in a series of breast phyllodes tumours (PTs) in Asian women, and to determine the utility of immunohistochemical expression of p53 and CD117 in the stromal component.

MATERIALS AND METHODS

Breast PTs, diagnosed between January 1992 and December 2002 at the Department of Pathology, Singapore General Hospital, were classified into benign, borderline and malignant categories. Surgical margins were evaluated as complete or diffusely involved. Patient follow-up was obtained from casenotes and the Singapore Cancer Registry. Tissue microarrays (TMAs) were constructed using the 2-mm punch on the Beecher arrayer. p53 and CD117 immunohistochemistry was applied on 4-microm sections cut from TMA blocks. Immunostaining intensity was graded as 0, 1+, 2+ or 3+, for nil, weak, moderate and strong reactivity. The proportion of stromal cells decorated was assessed. Statistical analysis utilised the software SPSS for windows 11.5. Survival curves were plotted using the Kaplan-Meier method, while multivariate analysis was accomplished using the stepwise Cox proportional hazards model. A P value of <0.05 was considered a significant result. For verification of protein expression results, a pure stromal population derived from laser capture microdissection was subjected to real-time polymerase chain reaction to determine p53 and CD117 mRNA upregulation.

RESULTS

Three hundred thirty-five women diagnosed with PT were aged 16 to 69 years (median, 42 years). Tumour size ranged from 0.9 to 25 cm (median, 4 cm). Histologic classification revealed 250 (74.6%) benign, 54 (16.1%) borderline and 31 (9.3%) malignant PTs. Surgical margins were focally involved in 186 (55.5%) cases, diffusely affected in 9 (2.9%) cases and complete in 139 (41.5%) cases. Stromal cells positively stained ranged from 1% to 80% (mean, 15%; median, 5%) for p53, and 1% to 25% for CD117 (mean, 8%; median, 3%). p53 and CD117 staining was associated with PT grade (P = 0.004, P <0.001). Forty-three (12.8%) women suffered 57 recurrences (mean and median follow-up of 30.3 and 20.4 months respectively). Nine (2.7%) died during follow-up, 7 from malignant disease (mean and median survival duration 37.6 and 23.6 months respectively). Complete margins (P = 0.033) resulted in reduced recurrence risk by 51.7%. Though tumour grade was associated with an increased hazard of 1.63, it was not significant (P = 0.28). Immunoexpression of p53 was not associated with recurrence (P = 0.447), while CD117 was (P = 0.001). Upregulation of p53 and CD117 mRNA was found in cases in which there was protein overexpression.

CONCLUSIONS

Involved surgical margins remain a key prognostic parameter in breast PT. Death from disease occurred in women with malignant PTs at presentation, underscoring the need to manage this group more aggressively. p53 staining can be used to corroborate malignancy in PT. CD117 was predictive of recurrence, and if further validated, its expression can be explored for therapeutic purposes. Preliminary molecular studies verify mRNA upregulation in p53 and CD117 overexpressed cases.

The evolving role of gene-based treatment in surgery

Background

The completion of the sequencing of the human genome in 2003 marked the dawn of a new era of human biology and medicine. Although these remarkable scientific advances improve the understanding of human biology, the question remains how this rapidly expanding knowledge of functional genomics affects the role of surgeons. This article reviews the potential therapeutic application of gene therapy for various surgical conditions.

Methods

The core of this review was derived from a Medline database literature search.

Results and conclusion

The currently available vectors in the field of gene therapy and their limitations for clinical applications were analysed. The achievements of gene therapy in clinical trials and the future ramifications for surgery were also explored. Whether gene therapy takes a major role in surgical practice will depend greatly on the success of future vector development. Advances in viral vector technology to reduce the inflammatory effect, and improvements in the efficiency of gene delivery using non-viral vector technology, would allow this form of therapy to become more clinically applicable.

Pathological diagnosis of columnar cell lesions of the breast: are there issues of reproducibility?

AIMS

To assess inter/intraobserver variability in the interpretation of a series of digitised images of columnar cell lesions (CCLs) of the breast.

METHODS

After a tutorial on breast CCL, 39 images were presented to seven staff pathologists, who were instructed to categorize the lesions as follows: 0, no columnar cell change (CCC) or ductal carcinoma in situ (DCIS); 1, CCC; 2, columnar cell hyperplasia; 3, CCC with architectural atypia; 4, CCC with cytological atypia; 5, DCIS. Concordance with the tutor's diagnosis and degree of agreement among pathologists for each image were determined. The same set of images was re-presented to the pathologists one week later, their diagnoses collated, and inter/intraobservor reproducibility and level of agreement for individual images analysed.

RESULTS

Diagnostic reproducibility with the tutor ranged from moderate to substantial (kappa values, 0.439-0.697) in the first exercise. At repeat evaluation, intraobserver agreement was fair to perfect (kappa values, 0.271-0.832), whereas concordance with the tutor varied from fair to substantial (kappa values, 0.334-0.669). There was unanimous agreement on more images during the second exercise, mainly because of agreement on the diagnosis of DCIS. The lowest agreement was seen for CCC with cytological atypia.

CONCLUSIONS

Interobserver and intraobserver agreement is good for DCIS, but more effort is needed to improve diagnostic consistency in the category of CCC with cytological atypia. Continued awareness and study of these lesions are necessary to enhance recognition and understanding.

Recurrent prostatic stromal tumour of uncertain malignant potential (STUMP) presenting with urinary retention 6 Years after transurethral resection of prostate (TURP)

CLINICAL PRESENTATION

A 56-year-old Chinese male with previously diagnosed prostatic stromal tumour of uncertain malignant potential (STUMP) presented with urinary retention 6 years after transurethral resection of prostate (TURP).

TREATMENT AND OUTCOME

Cystoscopy showed a papillary tumour of the prostatic urethra causing near-complete obstruction. Repeat TURP was performed. He has been asymptomatic since.

CONCLUSION

There has been fewer than 100 cases of this lesion reported worldwide. Definitive treatment is not well established. Longterm follow-up to monitor progression and possible recurrence is required, and repeat TURP or radical surgery may be necessary.

After the Indian Ocean tsunami: Singapore's contribution to the international disaster victim identification effort in Thailand

This paper describes the international disaster victim identification (DVI) response mounted in Thailand, with particular reference to Singapore's contribution to this process, in the wake of the Asian tsunami of 26 December, 2004, which devastated parts of more than 10 countries in and around the Indian Ocean and claimed more than 200,000 lives. Although Singapore was unscathed by this natural calamity, over 30 Singaporean visitors were counted amongst the thousands of deceased victims, mostly in Thailand. The systematic application of forensic pathology, forensic dentistry, DNA profiling, and fingerprinting to human identification, especially of the bodies of various nationalities that were in advanced states of putrefaction, was crucial to the entire DVI process. The authors perceive that the resource implications arising from such a disaster, which is unprecedented in both its scale and reach in the international history of DVI, are immense. Forward planning, adequate funding and international cooperation are essential to mounting an effective response to any major mass disaster of the future.

Extracellular signal-regulated kinase induces cyclin D1 and Cdk-2 expression and phosphorylation of retinoblastoma in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies in Southeast Asia. Hyperphosphorylation of retinoblastoma (pRB) by cyclin/CDKs in G1/S transition is required for its inactivation and cell cycle progression. In the present study, we report that phosphorylation of pRB at Ser780 and Ser795 was detected in 71% (33 of 46) and 63% (29 of 46) of HCCs examined respectively. pRB protein was undetectable in 13% (6 of 46) of HCCs examined. Phosphorylated pRB was localized in the nuclei of hepatocarcinoma cells. Benign hepatocytes exhibited very weakly or no nuclear staining for phosphorylated pRB. Over-expression of E2F-1, cyclin D1, Cdk-2, Cdk-4 and cyclin A was found in 64% (30 of 46), 43% (26 of 46), 28% (11 of 46), 71% (33 of 46) and 63% (29 of 46) of HCCs examined respectively and this was correlated with elevation of ERK. Treatment of HepG2 cells with MEK1/2 inhibitor U0126 resulted in cell cycle arrest, downregulation of cyclin D1 and Cdk-2 expression and inhibition of pRB phosphorylation at Ser780 and Ser795. Ectopic expression of activated MEK1 in HepG2 cells increased cyclin D1 and Cdk-2 expression, phosphorylation of pRB at Ser780 and Ser795, and percentage of cells in S phase. Our data indicate that activated ERK plays an important role in cyclin D1 and Cdk-2 expression and phosphorylation of pRB at Ser780 and Ser795 in liver cancer cells.

Systemic administration of naked DNA with targeting specificity to mammalian kidneys

A major challenge for gene therapy is to be able to deliver efficiently the gene of interest to specific cell types. Here we describe a safe and simple effective naked DNA gene delivery method, via inferior vena cava (IVC) injection, to the recipient's kidneys. It was further demonstrated that gene expression was concentrated in the proximal tubular epithelial cells of the cortico-medullary region of the kidney. Confocal microscopy analyses demonstrated the presence of the exogenous DNA in the renal cell membrane 10 min postgene delivery. However, it was only by 30 min that the presence of the exogenous DNA could be detected in the cell cytoplasm and in the nuclei of the renal cells. Stable expression of the beta-galactosidase gene could be detected for up to 35 days and no toxicity or any adverse pathological effect associated with the delivery method could be observed. Importantly, this IVC gene delivery method could promote the targeting of genes to carcinoma established in the kidney of SCID mice. These results provide the first evidence to support that stable gene expression could be achieved in the renal cells of kidney and the established carcinoma in the kidneys following in vivo gene delivery with naked DNA and could therefore provide the potential to design protocols for the gene therapy of the kidney diseases.

Ductal carcinoma in situ with spindle cells: a potential diagnostic pitfall in the evaluation of breast lesions

AIMS

To evaluate the morphological features of 11 cases of breast ductal carcinoma in situ (DCIS) with spindle cells and to propose an approach to distinguish it from benign mimics. The association with neuroendocrine differentiation was also investigated.

METHODS

Cases of breast DCIS with a spindle cell component diagnosed in the Department of Pathology, Singapore General Hospital, between June 1996 and January 2003, were included in the study. The histological characteristics were documented, and immunohistochemistry for neuroendocrine markers, hormone receptors, cerbB2, smooth muscle actin (SMA) and high-molecular-weight (HMW) cytokeratins, was carried out. Electron microscopy was carried out on reprocessed paraffin-embedded material in three cases.

RESULTS

Of 11 women diagnosed with DCIS with spindle cells, four presented with nipple discharge, six with a breast lump, while one was discovered to have a screen detected density. The tumour size ranged from 3 to 41 mm. The proportion of spindle cells varied from 10% to 80% of the in-situ tumour cell population. Nuclear grade was low in seven cases and intermediate in four. Necrosis was observed in two cases. Architectural pattern was papillary in six cases, and mixed in the rest. Microinvasion was present in two cases, with possible microinvasion in another two. Immunohistochemistry for neuroendocrine markers synaptophysin and chromogranin showed positive reactivity for at least one marker in all but three cases; one of these latter cases demonstrated ultrastructural neurosecretory granules. Oestrogen and progesterone receptors were expressed in 10 and nine cases, respectively, while cerbB2 was positive in only one case. HMW cytokeratin immunoprofile revealed a general lack of immunostaining within the abnormal cell population; likewise, no positivity for SMA of the cellular proliferation was detected.

CONCLUSIONS

Almost all DCIS lesions with spindle cells disclose neuroendocrine differentiation. Although the distinction from benign florid usual hyperplasia may pose a diagnostic histological problem, the presence of diffuse neuroendocrine expression, in conjunction with the pattern of HMW keratin profile on immunohistochemistry, supports an in-situ neoplastic process. The absence of SMA immunostaining, in conjunction with negative reactivity for cytokeratins 5/6 and 14, makes the possibility of a myoepithelial proliferation unlikely.

The HercepTest and routine C-erbB2 immunohistochemistry in breast cancer: any difference?

INTRODUCTION

The proto-oncogene c-erbB2, located on chromosome 17q21, encodes a 185-kD transmembrane glycoprotein. It is known to be overexpressed, amplified, or both in 20% to 30% of breast cancers. C-erbB2 belongs to the human epidermal growth factor receptor (tyrosine kinase receptor) family that plays an important role in cell cycle regulation and differentiation. Although there are various methods to assess c-erbB2 status in breast cancer, protein overexpression determined by immunohistochemistry and gene amplification using fluorescence in situ hybridisation are most commonly utilised. This study compares the results of the DAKO HercepTest with the immunohistochemical assay (A0485, DAKO), which is routinely used in our pathology laboratory.

MATERIALS AND METHODS

Paraffin-embedded breast cancer tissues from 41 patients operated in a tertiary hospital during the year 2000 were subjected to immunohistochemistry by the above methods. C-erbB2 positivity was defined by cytoplasmic membrane staining of 2+ or 3+ intensity.

RESULTS

Overexpression of c-erbB2 protein was present in 36.6% and 41.5% of cases when detected by HercepTest and the DAKO A0485 antibody, respectively. There was almost perfect agreement between both methods (k = 0.898) when positive versus negative results were considered, and moderate agreement in terms of individual staining intensities (k = 0.554).

CONCLUSION

Routine immunohistochemistry using the DAKO A0485 antibody is a reliable, cost-effective alternative to the HercepTest in determining prognosis and suitability of patients for Herceptin therapy.

Endorectal magnetic resonance imaging and spectroscopy for the detection of tumor foci in men with prior negative transrectal ultrasound prostate biopsy

PURPOSE

We determined the ability of combined endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) to detect prostate cancer foci prospectively in men with prior negative transrectal ultrasound (TRUS) prostate biopsy.

MATERIALS AND METHODS

Endorectal MRI with spectroscopy was performed in 24 consecutive patients with 1 or more prior negative TRUS prostatic biopsies for persistently increased prostate specific antigen and/or abnormal digital rectal examination. All studies were interpreted by a dedicated radiologist who reported areas of interest in the peripheral zone as normal, equivocal or suspicious on MRI and MRSI separately. Equivocal and suspicious areas were then correlated with a 3-dimensional prostate model. All patients underwent a standard TRUS 10-core peripheral zone biopsy with up to 4 additional biopsies targeted at the equivocal or suspected sites.

RESULTS

Prostate cancer was detected in 7 of 24 subjects (29.2%). Considering the equivocal category as test negative the sensitivity, specificity, positive and negative predictive values, and the accuracy of MRI, MRSI and combined MRI/MRSI for the detection of prostate cancer were 57.1%, 57.1% and 100.0%, 88.2%, 82.4% and 70.6%, 66.7%, 57.1% and 58.3%, 83.3%, 82.1% and 100%, and 79.2%, 75.0% and 79.2%, respectively. The site of positive biopsy correlated correctly in 50% and 28.6% of MRI and MRSI labeled suspicious cores, respectively.

CONCLUSIONS

MRI and MRSI have the potential to identify cancer foci and direct TRUS in patients with a previous negative TRUS biopsy. Further, larger studies are required to quantify the amount of benefit.

The effect of promethazine on postoperative pain: a comparison of preoperative, postoperative, and placebo administration in patients following total abdominal hysterectomy

BACKGROUND

Histamine receptors are involved in the development of inflammatory pain and hyperalgesia, and the use of antihistamines is advocated as an alternative for pain therapy and treatment of postoperative nausea and vomiting. We investigated the influence of timing of promethazine administration on postoperative pain outcomes.

METHODS

Ninety female patients undergoing total abdominal hysterectomy were randomly divided into three groups. All individuals received infusions of promethazine and normal saline before anaesthesia induction, and postoperatively the Pre group received promethazine 0.1 mg kg(-1) before anaesthesia and saline postoperatively, and the Post group received saline before anaesthesia and promethazine 0.1 mg kg(-1) postoperatively, while the Control group received two equivalent volumes of saline. Patients were treated using patient-controlled intravenous analgesia (PCA). The primary endpoint was pain intensity and morphine consumption. The secondary endpoint was postoperative nausea and vomiting.

RESULTS

Postoperative morphine usage was significantly lower in the Pre group (24.1 +/- 3.9 mg) relative to the Post (30.0 +/- 4.6 mg) and Control groups (32.1 +/- 4.8 mg) during the first 24 h postoperatively (P<0.05). The number and incidence of patients suffering from postoperative nausea in the first 24 h was six (21%), seven (23%), and 15 (47%) in the Pre, Post, and Control groups, respectively (P<0.05). The number and incidence of patients vomiting in the first 24 h was three (10%), two (7%), and 10 (32%) in the Pre, Post, and Control groups, respectively (P<0.05). The number of patients asking for rescue antiemetic in the first 24 h was one (3%), two (7%), and seven (22%) in the Pre, Post, and Control groups, respectively (P<0.05).

CONCLUSIONS

Our results suggest that preoperative administration of promethazine 0.1 mg kg(-1) reduces postoperative morphine consumption compared with postoperative and placebo administration, and that use of promethazine reduces PONV and the number of patients asking for rescue antiemetic in the first 24 h after surgery when compared with placebo.

Phenotypic and functional differences between human saphenous vein (HSVEC) and umbilical vein (HUVEC) endothelial cells

The vascular endothelial cell (EC) plays an essential role in the pathogenesis of inflammation, transplant rejection and tumour metastasis. Most research on vascular ECs uses human umbilical vein endothelial cells (HUVECs). However, HUVECs are derived from immune-naive foetal tissue, and show significant functional differences from adult vascular endothelium. In this paper, we characterise an alternative model based on human saphenous vein ECs (HSVECs), describe their culture conditions and provide a detailed functional comparison with HUVECs. Compared with HUVECs, HSVECs show an increased sensitivity to ox-LDL and a reduced response to cytokines, as indicated by adhesion molecule expression as well as leukocyte adhesion and transmigration. With respect to their ability to present antigen, HSVECs have a higher level of HLA-DR, CD40 and ICOS-L following cytokine stimulation. In addition, HSVECs upregulate the costimulatory ligand CD80 (B7.1) following CD40 ligation, and support allogeneic T cell proliferation, while HUVECs fail to express CD80. Due to differential expression of adhesion molecules, poorly differentiated tumour cell lines also showed more adhesion to HSVECs than to HUVECs. These results indicate that HSVECs have advantages over HUVECs for studying adult vascular endothelial pathology in vitro.

Gastrointestinal stromal tumor of the anus

We report a rare case of gastrointestinal tumor of the anus with an unusual presentation as a perianal lipoma. A 65-year-old man presented with a 2-month history of a painless perianal lump clinically resembling a perianal lipoma. Endoanal ultrasonography revealed a 3 x 3 cm2 mass in the intersphincteric plane. Following initial excision of the lesion, histological analysis revealed a stromal lesion comprising fascicles of spindle cells with a mitotic count of 4 per 50 x high power field. Immunohistochemical analysis displayed positive reactivity for CD34 with focal staining for CD117; S100, smooth muscle actin and desmin were not expressed. No evidence of local or distant metastatic disease was found on computed tomography of the abdomen and pelvis. The patient subsequently underwent abdominoperineal resection. The resected specimen contained a mural nodule measuring 0.7 cm, located 5 cm from the distal margin and 2 mm from the radial margin. Histological analysis confirmed a stromal tumor composed of spindle cells with mitoses up to 2 per 10 x high power field. The patient's recovery was uneventful and he was free of recurrence at the 1-year follow-up. Gastrointestinal stromal tumors of the anal canal are an extremely rare occurrence, and may mimic benign perianal lesions. Tumor size and mitotic count are the most important factors in prognosticating outcome. Oncologic resection and protracted follow-up must factor in their predilection for late recurrence and metastatic spread. The role of adjuvant therapy with STI571 here remains to be clearly defined.

Single institution's initial experience with sentinel lymph node biopsy in breast cancer patients

BACKGROUND

The sentinel lymph node is the first draining node from a cancer-bearing area and is therefore the first to manifest metastasis. In breast cancer it has been shown to predict the axillary status. Axillary dissection provides information determining prognosis and need for adjuvant therapy but carries a certain morbidity. Our aim was to determine the feasibility of detecting the sentinel node in a teaching hospital and whether the sentinel node accurately predicts the axillary status.

METHODS

All patients with stage I and II breast cancer and non-palpable axillary nodes were eligible, including those with previous excision biopsy. We excluded pregnant women, those with previous axillary surgery and women with advanced breast cancer with enlarged axillary nodes. The sentinel node was detected with technetium-99m-labelled tin colloid and vital blue dye and removed, and axillary clearance was performed.

RESULTS

A total of 312 patients were examined from August 1996 to December 1998. The mean age was 53 years (range 28-83) and mean tumour size 2.6 cm (range 0.2-9.0). The detection rate of the sentinel node was 86%. The sentinel lymph node predicted the axillary status with a sensitivity of 83% and specificity of 100%. The false-negative rate was 16.7%.

CONCLUSIONS

Detection of the sentinel lymph node is feasible and it can accurately predict the nodal status of the axilla. However, the high false-negative rate precludes as yet the use of sentinel lymph node biopsy in replacing axillary clearance as the standard of care for breast cancer.

Antibody targeted gene transfer to endothelium

BACKGROUND

One of the drawbacks of the currently available vectors for gene therapy is the lack of selectivity in gene delivery. We have therefore investigated a strategy to generate immunoliposomes to target non-viral vectors to cell surface receptors on endothelium.

MATERIALS AND METHODS

We have developed a novel method of coupling antibodies (Abs) to liposomes complexed to DNA, using mild heat treatment to aggregate the immunoglobulin G (IgG). The interaction of plasmid DNA, liposomes and Abs was measured using a gel retardation assay and a resonant mirror biosensor. The size of the transfection complex was determined by light scattering, and the binding and internalization of the complex to cells was followed using flow cytometry. The transfection ability was tested on cell lines and primary cells in vitro and human corneal or vascular tissues ex vivo.

RESULTS

The interaction of antibodies with liposomes is relatively stable (t(1/2) congruent with 45 min). The size of the liposome, Ab and DNA complex was found to be around 500 nm in 4% BSA. The addition of anti-transferrin receptor Abs increased the internalization of the liposome-DNA complex into cells. Abs against both transferrin receptor and E-selectin were shown to augment transfection efficiency of liposomes to cell expressing the appropriate antigens. They are also shown to be efficient in mediating gene delivery to corneal and vascular tissues ex vivo.

CONCLUSIONS

We have shown that our novel vector is capable of in vitro and ex vivo gene delivery to cells and human tissues including cornea, artery and vein. In particular, an Ab against E-selectin was effective at selectively delivering genes to activated endothelial cells expressing the adhesion molecule. Such a strategy will have applications for targeting these tissues prior to transplantation or autologous grafting, and, in the longer term, may allow in vivo targeting of gene therapy to inflammatory sites.

CerbB2 status in breast cancer: pathologic issues

INTRODUCTION

CerbB2 status determination in breast cancer is currently performed for predictive and prognostic information. However, much has yet to be learned about the accuracy, reproducibility and clinical correlation of the different testing methods available today. This is a review of the testing methods commonly in use and their applications in the management of breast cancer.

METHODS

A Medline search for review articles with keywords cerbB2, Her2 testing, immunohistochemistry (IHC), fluorescence in situ hybridisation (FISH) and breast cancer was done. Manual cross-referencing from the afore-mentioned articles and perusal of the package inserts, recommendations and manuals from the manufacturers of various commercially available test kits were also performed.

RESULTS

The 2 main methods of testing in use in most routine laboratories are IHC and FISH on formalin fixed, paraffin embedded, breast cancer tissue. There is no single, universally accepted method and the plethora of testing and interpretative protocols has confounded the issue of clinical correlation of cerbB2 status with outcome and patient selection for therapy. The current consensus in the literature is leaning towards FISH; however, as pointed out in this paper, the use of FISH as a routine test in most diagnostic laboratories is not yet a reality mainly due to cost, technical and manpower constraints. In this regard, IHC is by default the preferred choice in many routine laboratories.

CONCLUSION

Universal standardisation of testing methods for cerbB2 status determination, together with further clinical studies on the correlation of each method with outcome and response to therapy, will aid in the identification of the ideal method for stratifying patients with breast cancer into prognostic and optimal therapeutic groups.

Improved detection rate of prostate cancer using the 10-core biopsy strategy in Singapore

OBJECTIVES

To evaluate if changing the biopsy regime to 10 cores might improve the positive predictive value (PPV) of elevated prostate-specific antigen [PSA, elevated range, 4 to 20 ng per ml, normal range, < 4 ng per ml] for the diagnosis of prostate carcinoma.

METHODS

From February 2000 to April 2001, 191 patients, mean age 64 years [range, 38 to 85 yr], underwent transrectal ultrasound [TRUS] for either elevated PSA [elevated range, 4 to 20 ng per ml] and/or abnormal digital rectal examination [DRE]. A 10-core TRUS-guided biopsy of the prostate was performed. This included the standard sextant biopsy and two additional cores for each far lateral zone.

RESULTS

Using this technique, 47 out of 191 patients [24.6%] had prostate cancer. The PPV for PSA levels of 4.1 to 10.0 ng per ml and 10.1 to 20.0 ng per ml were 19.3% and 35.4%, respectively. The lateral cores contributed 21.3% of the cancer cases, which would have been missed if only sextant biopsies were performed.

CONCLUSIONS

With the 10-core biopsy method, the PPV for prostate cancer for patients with a PSA in the range of 4 to 20 ng per ml was in the range of 25%. This is significantly different from previous reports. The reason for this may be due to the adoption of a better, more uniform and systematic biopsy strategy for patients with elevated PSA, or it may be a true reflection of the current population incidence. Hence, this biopsy strategy is highly recommended.

Pseudodicentric (16;12)(q11;p11.2) in a type AB (mixed) thymoma

Genetic alterations of thymomas are rarely described in the literature. In this study, a previously unreported instance of aberrant karyotypic change consisting of 45,XX,pseu dic(16;12) (q11;p11.2) [cp23]/87-90,idemx2[cp4] in a Masaoka Stage II mixed thymoma or type AB thymoma affecting a 56-year-old Chinese woman is detailed. Abnormalities involving 12p containing important tumor suppressor-like genes have been documented especially in hematological malignancies. Recently, recurrent losses involving 16q, a locus known to harbor several tumor suppressor genes, have been described in type C thymomas (squamous cell carcinoma), suggesting a possible relationship between type AB thymoma and type C thymoma. Whether these genes are involved in the pathogenesis of type AB thymoma remain to be clarified and it is currently unclear if cytogenetic studies may eventually play a role in the classification of thymic tumors.

Bilateral synchronous renal oncocytoma: a case report and review

INTRODUCTION

Renal oncocytoma is a rare benign tumour.

CLINICAL PICTURE

A 73-year-old man presented with bilateral renal tumours, suggestive of renal cell carcinoma (RCC). Nephron-sparing surgery (NSS) and radical nephrectomy were performed. Both specimens revealed renal oncocytoma on final histology. A review of nephrectomy specimens showed 4 other solitary oncocytomas out of 250 RCCs over the period 1991 to 2000. Diagnosis of oncocytoma could only be firmly established by careful histological evaluation to exclude RCC.

TREATMENT

Renal oncocytoma carries a good prognosis. The use of NSS for synchronous bilateral renal masses is highlighted.

CONCLUSION

NSS is recommended for renal oncocytoma wherever possible.

Pathology of ductal carcinoma in situ of the breast: a heterogeneous entity in need of greater understanding

Breast cancer is the commonest malignancy among Singapore women. Ductal carcinoma in situ (DCIS) is the putative precursor of the majority of invasive breast cancers, and its incidence has increased dramatically with mammographic screening. It is a heterogeneous disease--radiologically, pathologically and biologically. While the diagnosis of breast cancer in its pre-invasive phase, DCIS, allows the likelihood of cure with effective therapy, issues that surround its pathological heterogeneity are often not fully understood nor recognised. In this paper, the pathology and natural history of breast DCIS are reviewed; with emphasis on pathological classification schemes that attempt to predict recurrent disease or progression to invasive cancer. The potential role of biological markers is also evaluated. Atypical ductal hyperplasia, a lesion that is often difficult to distinguish from low grade DCIS; the significance and definition of microinvasion; and the value of fine needle aspiration cytology in DCIS are discussed. In addition, pathologic-radiologic correlations of local screen-detected cases of breast DCIS are presented. Awareness of the pathological parameters that impact on the biological behaviour of breast DCIS will enable appropriate management strategies; avoiding overtreatment in biologically indolent disease, while optimising adequate therapy for aggressive lesions.

Leiomyomatosis-like lymphangioleiomyomatosis of the colon in a female with tuberous sclerosis

Smooth muscle lesions of the large bowel, excluding the rectum, are generally rare, and diffuse smooth muscle lesions, termed leiomyomatosis, are even rarer. In this report, we document, for the first time, leiomyomatosis-like lymphangioleiomyomatosis (LAM) of the ascending, transverse, and descending colon in association with bilateral renal angiomyolipoma (AML) in a 30-year-old Chinese female with tuberous sclerosis complex (TSC). She presented with protracted constipation for which a colectomy was performed. Histology disclosed multiple confluent nodular CD34 and CD117 negative smooth muscle proliferation within the large bowel wall, whereas the renal biopsy revealed typical features of AML. Interestingly, the epithelioid smooth muscle cells of both the colonic and renal lesions were HMB45 positive, suggesting that leiomyomatosis-like LAM of the colon, pulmonary LAM and AML are closely related entities. The patient remained free of complications for the last five years after surgery. Leiomyomatosis-like LAM of the large bowel probably represents another manifestation of the tendency of TSC to be associated with proliferative lesions.

Case report: follicular adenoma in a thyroglossal duct remnant arising entirely within the hyoid bone

INTRODUCTION

We describe here the first reported case of a follicular adenoma arising from a thyroglossal duct remnant within the hyoid bone in Singapore.

CLINICAL PICTURE

A 32-year-old woman presented with an asymptomatic lump in the anterior midline of her neck of three months' duration. CT scan showed an expansile lesion localised to the medulla of the body of the hyoid.

TREATMENT

A well-defined intrahyoidal mass was found at surgery. Histology revealed a follicular adenoma arising from maldescended thyroid tissue within the hyoid bone.

OUTCOME

Recovery was uneventful.

CONCLUSION

It is important to consider thyroglossal duct carcinomas as a differential diagnosis when evaluating anterior neck lumps.

Correlation of nuclear morphometry with pathologic parameters in ductal carcinoma in situ of the breast

Morphometric features of nuclear perimeter, nuclear area, feret ratio, and feret circle were studied in a series of 64 cases of ductal carcinoma in situ (DCIS) of the breast in Singapore women. The results were compared with pathologic parameters of tumor size, nuclear grade, necrosis, cell polarization, and architectural pattern. There was statistically significant correlation between nuclear perimeter and area with all the pathologic parameters, with the strongest association observed for nuclear grade (P <.0001). Higher grade nuclei as assessed histologically were associated with larger nuclear area (44.14 microm(2) in low-grade lesions, 47.77 microm(2) in intermediate-grade lesions, and 72.05 microm(2) in high-grade lesions) and perimeter (25.94 microm in low-grade nuclei, 27.12 microm in intermediate-grade nuclei, and 33.66 microm in high-grade nuclei). DCIS lesions with necrosis and absence of polarization also revealed increased nuclear area and perimeter (P <.05). Comedo architecture was associated with larger nuclear area and perimeter (65.97 microm(2), 31.7 microm) than the papillary subtype (42.17 microm(2), 25.29 microm), with the mixed morphologic pattern disclosing intermediate values (54.83 microm(2), 29.43 microm). There was direct correlation for tumor size with nuclear area and perimeter (P <.01). No similar relationship was found between pathologic parameters and feret ratio or circle, indicating that nuclear roundness or lack of it did not factor as a significant component in the pathologic assessment.