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Biomedical subjects

K Y Lam

Publications and source records attributed to K Y Lam.

At least 37 records · Page 2Linked to original sources
PubMed2001

Prognostic significance of serum p53 protein and p53 antibody in patients with surgical treatment for head and neck squamous cell carcinoma.

OBJECTIVES: This study aims at investigating the prognostic values of serum p53 protein and anti-p53 antibody in patients undergoing surgical treatment for head and neck squamous cell carcinoma (HNSCC). METHODS: Serum p53 protein and anti-p53 antibody concentrations were determined by an enzyme-linked immunosorbent assay (ELISA) in 75 patients with HNSCC and 28 healthy controls. In 28 patients, formalin-fixed tumor tissues were also available for immunohistochemical staining by an anti-p53 DO7 monoclonal antibody. The results were correlated with the clinicopathologic parameters. RESULTS: The mean preoperative serum concentration of p53 protein in patients with HNSCC was significantly higher than healthy controls (59.45 pg/mL vs 16.4 pg/mL, p =.007). Preoperative serum p53 antibody was present in 23 (31%) patients and was present in one healthy control. Eighteen (62%) tumor tissues showed p53 overexpression by immunohistochemistry. The presence of serum anti-p53 antibody before operation was associated with a significantly higher incidence (65%) of nodal metastasis compared with 27% nodal metastasis in patients with absence of serum anti-p53 antibody (p =.002). CONCLUSION: Preoperative serum p53 antibody was a significant prognostic factor for nodal metastasis of HNSCC.

Adult↗
PubMed2001

Esophageal blue nevus: an isolated endoscopic finding.

BACKGROUND: The occurrence of blue nevus has seldom been reported in extracutaneous sites and with no record in the esophagus. CASE REPORT: A blue nevus was reported in the esophagus of a 58-year-old Chinese woman. On endoscopic examination, the lesion presented as linear patches of bluish pigmentation in the esophagus. The patient was free of symptoms 3 years after the endoscopic examination. CONCLUSIONS: We believe this represents the first reported case of blue nevus in the esophagus. The clinicopathologic features, differential diagnoses, and the nature of the lesion are discussed, along with a review of the literature.

Esophageal Diseases↗
PubMed2001

Oesophageal basaloid squamous cell carcinoma: a unique clinicopathological entity with telomerase activity as a prognostic indicator.

Oesophageal basaloid squamous cell carcinoma (BSCC) is uncommon and has been reported to have a worse prognosis than squamous cell carcinomas (SCCs), but this tumour has not been fully characterized. The aim of the present study was to analyse the clinicopathological features of a large cohort of patients with oesophageal BSCC treated at a single institution. The pathology of 756 primary oesophageal cancers treated between January 1989 and December 1998 was reviewed. Tumours that fulfilled the diagnostic criteria of BSCC were identified and were compared with SCC. Their expression of MIB-1, DNA ploidy, and telomerase activity were also studied. Thirty Chinese patients (25 men and five women) with BSCC were found, comprising 4% of patients with oesophageal cancer treated by surgical resection in the study period. Their median age was 67 years (range 40-78 years). Dysphagia was usually the main presenting symptom. Other concomitant malignant tumours were seen in three patients and paraneoplastic glomerulopathy in one. Five tumours were located in the upper third, 19 in the middle third, and six in the lower third. The median length was 5.8 cm (range 2-12 cm). The median MIB-1 score of BSCC was 750 (range 400-858) and was higher than that of SCC (p=0.003). The primary tumour and metastatic BSCC were aneuploid, as detected by flow cytometric analysis in nine patients. Telomerase activity was positive in 95% (19 out of 20) of the cases analysed. The 5-year survival of patients with BSCC was 12%. Distant metastases were seen in 53% (n=16); lung and liver were the most common sites. The median survival of patients with tumours which had a high level of telomerase activity was significantly shorter than those with low levels of telomerase activity (1 vs. 27 months) (p=0.001). The median survival of patients with BSCC and SCC was 26 and 16 months, respectively (p=0.3). In conclusion, BSCC has distinctive clinicopathological features and its long-term prognosis is no worse than SCC. The level of telomerase activity may have a prognostic role.

Adult↗
PubMed2001

Solid-cystic papillary tumor of the pancreas in children.

Solid-cystic papillary tumor (SCPT) of the pancreas is a rare neoplasm in children. The current study attempted to estimate the incidence and possible pathological origin of the tumor. Clinicopathologic features of the children under the age of 16 years with pancreatic tumors managed in a single institution between January 1993 and November 1999 were reviewed. Representative blocks of SCPT specimens were immunostained for neuron-specific enolase (NSE) chromogrannin, synaptophysin, insulin, glucagon, somatostatin, and gastrin. There were three SCPTs, two pancreatic endocrine tumors, and one acinar cell carcinoma during the study period. The estimated yearly incidence in the referral area of 2 million population is about 0.01 pediatric SCPT per year per 100,000 population. The children underwent surgical removal of the tumors. Postoperatively, they were followed up for 6 months to 4 years and were well. Immunostaining for NSE, chromogranin, synaptophysin, insulin, somatostatin, and gastrin was negative in all cases. SCPT may thus be the most common pancreatic tumor in the Asian pediatric population. The pathological origin of the tumor remains unclear and requires further investigations.

Adolescent↗
PubMed2001

A comparative study of the clinicopathological significance of E-cadherin and catenins (alpha, beta, gamma) expression in the surgical management of oral tongue carcinoma.

PURPOSE: E-cadherin and catenins are important epithelial adhesion molecules in normal epithelium. Loss of E-cadherin-catenin adhesion is an important step in the progression of many epithelial cancers. E-cadherin and catenins expression in carcinoma of the tongue were evaluated in relation to their clinicopathological features and prognostic values. METHOD: Immunohistochemical staining was carried out with E-cadherin and (alpha, beta, gamma)-catenin monoclonal antibodies for 85 surgical specimens of oral tongue carcinoma, nine matched metastatic lymph nodes, and seven locally recurrent tumours. RESULTS: There was under-expression in 85% of E-cadherin, 94% of alpha-catenin, 89% of beta-catenin, and 83% of gamma-catenin in the primary tumours. There was no correlation of E-cadherin/catenin expression with sex, age, cancer stage, and differentiation. Nodal metastasis was found in 68% of patients with weak expression of gamma-catenin compared with 9% with strong expression in primary tumours (chi-square, P = 0.02). E-cadherin was a significant prognostic factor for survival and recurrence; patients with weak E-cadherin expression had 53% 5-year survival compared with 85% with strong expression (Wilcoxon, P = 0.0159). CONCLUSIONS: Both E-cadherin and catenins were highly under-expressed in oral tongue carcinoma, metastatic lymph node, and recurrent tumour. gamma-catenin had predictive value for nodal metastasis. E-cadherin was, however, a more important prognostic factor for recurrence and survival.

Adolescent↗
PubMed2001

A critical examination of adrenal tuberculosis and a 28-year autopsy experience of active tuberculosis.

OBJECTIVE: Tuberculosis is potentially fatal and adrenal gland involvement is uncommonly reported. The aims of the current study were to define the characteristics of tuberculosis in hospitalized patients and to analyse the features of adrenal tuberculosis. DESIGN: Retrospective analysis of autopsies and adrenalectomies. PATIENTS: 13,762 patients (13492 at autopsies and 270 at adrenalectomy). MEASUREMENTS: The presence of active tuberculosis, the predisposing factors, the pathological features and organs of involvement were examined. RESULTS: Active tuberculosis was present in 871 patients (6.5% of all 13492 autopsies). It was first diagnosed in 70% of these patients during autopsy. Cancers and a history of recent major operations were the 2 main concomitant factors in the patients with tuberculosis. Extra-pulmonary tuberculosis was seen in 261 patients (30%). The five most common extra-pulmonary sites of tuberculosis were the liver, spleen, kidney, bone and adrenal gland. Adrenal tuberculosis was seen in 52 of the 871 patients (6%) with active tuberculosis at autopsy and in 3 patients at adrenalectomy. The adrenal gland was the only organ involved by active tuberculosis in 14 of these 55 patients (25%; 35 men, 20 women). Tuberculosis was evident on macroscopic examination of the adrenal glands in 46% of the patients. On histological examination, caseous necrosis and granulomatous inflammation with Langhan's giant cells were seen in 71% and 40% of patients, respectively. Seven patients presented with signs and symptoms of Addison's disease due to bilateral adrenal involvement. Langhan's giant cells were frequently seen in histological sections and bilateral enlargement of the adrenal glands was often noted. Fine needle aspiration cytology was not useful for diagnosing adrenal tuberculosis. CONCLUSION: Unexpected and extra-pulmonary tuberculosis such as adrenal tuberculosis has been a common problem. A high index of suspicion, correct diagnosis and proper treatment are essential for the management of tuberculosis.

Addison Disease↗
PubMed2001

The clinicopathological significance of bcl-2 expression in the surgical treatment of laryngeal carcinoma.

Bcl-2 expression was studied by immunohistochemistry on laryngectomy specimens from 176 patients. Of the 176 tumours, 11% had positive bcl-2 staining. Bcl-2 expression was significantly correlated with tumour grade: 5% of well-differentiated tumours, 12% of moderately-differentiated tumours and 23% of poorly-differentiated tumours had positive expression of bcl-2. Nodal metastases were also found to be significantly related to bcl-2 expression: 36% of nodal metastases for negative bcl-2 expression compared with 70% for positive expression. The risk of nodal metastases increased significantly with the presence of bcl-2 expression, moderate or poor differentiation and supraglottic involvement. The risk of nodal metastases increased significantly with the presence of increasing numbers of risk factors: 11% without risk factor, 21% with one risk factor, 49% with two risk factors and 77% with three risk factors. Bcl-2 expression in laryngeal carcinoma is significantly correlated with tumour grade and nodal metastases. It has added prognostic value for nodal metastases together with tumour grade and site of tumour involvement.

Carcinoma, Squamous Cell↗
PubMed2001

Primary squamous cell carcinoma of the thyroid gland: an entity with aggressive clinical behaviour and distinctive cytokeratin expression profiles.

AIMS: Primary squamous cell carcinoma of the thyroid gland is uncommon. This study aims to identify the clinicopathological features and the pattern of expression of cytokeratins and oncoproteins in this tumour. METHODS AND RESULTS: Histological slides from Chinese patients with thyroid cancer treated in our institution from 1980 to 1999 were reviewed. Patients with primary squamous cell carcinoma of the thyroid were identified and their clinical records were analysed. The expression of cytokeratins (CKs), p53 and p21 in these cases were also studied by an immunohistochemical method. Four women (mean age 71 years) with squamous cell carcinoma of thyroid were found. The main presenting features were signs and symptoms of airway obstruction in three patients and neck swelling in one. The tumours were located at the right lobe (n=2), left lobe (n=1) or in both lobes of the thyroid (n=1). One patient died shortly after admission and the other three died within 4 months after thyroidectomy. The p53 protein was positive in 50% (2/4) of the tumours and p53+ tumours were poorly differentiated. The tumours were negative for p21. CK19 was expressed in all the tumours while CK7 expression was noted in 3/4 of the tumours. One carcinoma showed focal positivity to CK18. The tumours were negative for CKs 1, 4, 6, 10/13 and 20. The pattern of cytokeratin expression in squamous cell carcinoma of the thyroid gland was different from carcinoma showing thymus-like differentiation (CASTLE) of the thyroid gland and oesophageal squamous cell carcinoma. CONCLUSIONS: Squamous cell carcinoma of the thyroid has aggressive clinical behaviour and characteristic CK expression pattern. p53 over-expression in these tumours was associated with tumour differentiation.

Aged↗
PubMed2001

Telomerase activity in small cell esophageal carcinoma.

Small cell carcinoma of the esophagus is a rare and aggressive malignant tumor. Telomerase activation is common in human cancers. There is a lack of data on telomerase activity in esophageal small cell cancers. The present report studied the role of telomerase activity in esophageal small cell carcinoma. The clinicopathologic data of five patients with small cell carcinoma of the esophagus who underwent primary surgical treatment between 1991 and 2000 were studied. Telomeric repeat amplification protocol assays were used to investigate telomerase activity in these tumors. The proliferative activity (MIB-1) and p53 expression of these tumors were also studied using immunohistochemistry and correlated with the telomerase activity. All five small cell carcinomas showed detectable telomerase activity in the primary tumor. Two out of the five morphologically normal esophageal mucosae adjacent to the primary tumor had detectable telomerase activity. There was no correlation between the p53 expression, tumor stage, survival of patients, and the presence of telomerase activity. High MIB-1 expression in esophageal small cell carcinomas was associated with high telomerase activity. Telomerase activation is common in small cell carcinoma of the esophagus. This fact may find application in anti-telomerase treatment for this aggressive tumor.

Antigens, Nuclear↗
PubMed2001

Cytokeratin expression profiles in thyroid carcinomas.

AIMS: The aim of this study was to establish the cytokeratin expression profile of different types of thyroid carcinoma. MATERIALS AND METHODS: The expression of cytokeratins (CKs) 1, 4, 6, 7, 10/13, 18, 19 and 20 in 153 thyroid carcinomas were examined by immunohistochemistry. RESULTS: All papillary carcinomas (n=86) and follicular carcinomas (n=19) showed expression of CK7 and CK18. The staining was often diffuse. CK19 staining was expressed in all papillary carcinomas and the staining was often diffuse. The staining was noted in 68% of follicular carcinomas and the staining was often focal. No difference in the expression was noted between the minimally invasive and widely invasive follicular carcinomas. Poorly differentiated carcinomas (n=10) showed CK7, CK18, CK19 expression in 60%, 60% and 40%, respectively. Anaplastic carcinomas (n=25) expressed CK7 in 84%, CK18 in 80%, CK19 in 76% and CK10/13 in 16%. Medullary carcinomas (n=13) showed CK7 expression in 100%, CK18 in 85% and CK19 in 77%. None of the medullary carcinomas showed diffuse positivity to CK19. All the thyroid carcinomas were negative for CKs 1, 4, 6 and 20. CONCLUSIONS: Cytokeratin expression profile for each type of thyroid carcinoma was established.

Aged↗
PubMed2001

Routine parathyroid autotransplantation during thyroidectomy.

BACKGROUND: Parathyroid autotransplantation (PTHAT) during thyroidectomy has been shown to reduce the incidence of permanent hypoparathyroidism. Although selective PTHAT is most commonly adopted, the value of routine PTHAT has not been well documented. METHODS: From January, 1998 to March, 1999, an operative strategy incorporating routine autotransplantation of at least 1 parathyroid gland was used during thyroidectomy. The postoperative outcome of patients (n = 118) was evaluated and compared with patients (n = 271) operated during a policy of selective PTHAT (January, 1995 to October, 1997). RESULTS: Two or more parathyroid glands were autotransplanted in 26 patients (22%) while 92 patients (78%) received autotransplantation of 1 parathyroid gland. Postoperative hypocalcemia occurred in 29 patients (25%) and 2 patients (1.7%) had permanent hypocalcemia develop. When a policy of selective PTHAT was adopted, 98 patients (36%) underwent PTHAT, and 5 patients developed permanent hypocalcemia (1.8%). The incidence of postoperative hypocalcemia was higher in patients who underwent routine PTHAT (25%) compared with that in patients who underwent selective PTHAT (15%) (P =.014). In addition, the operating time was significantly longer when routine PTHAT was adopted (153 minutes vs 130 minutes; P <.001). CONCLUSIONS: A low incidence of permanent hypoparathyroidism can be achieved by either routine or selective PTHAT during thyroidectomy but routine PTHAT is associated with a high incidence of postoperative hypocalcemia.

Adult↗
PubMed2001

Primitive small round cell tumour of the adrenal gland presenting with fever of unknown origin and t(12;22)(q13;q12) cytogenetic finding.

This report describes a left adrenal tumour in a 16 year old Chinese girl who presented with fever of unknown origin. The histological and ultrastructural features of the adrenal tumour were those of a primitive small round cell tumour with neuroendocrine differentiation. Cytogenetic analysis of cultured tumour cells showed a reciprocal translocation t(12;22)(q13;q12). This is the first example of such a tumour being reported in the adrenal gland. The adrenal tumour was also the cause of the fever, which subsided after the removal of the tumour.

Adolescent↗
PubMed2001

The clinicopathological features and importance of p53, Rb, and mdm2 expression in phaeochromocytomas and paragangliomas.

AIMS: Phaeochromocytomas and paragangliomas are uncommon. The aims of this study were to analyse the characteristics and the possible roles of p53, Rb, and mdm2 alterations in these tumours. METHODS: The clinicopathological features of 65 patients (31 men, 34 women) with phaeochromocytomas or paragangliomas were analysed. The tumours were studied for the expression of p53, Rb, and mdm2 by immunohistochemical methods. RESULTS: Thirty nine of the patients had phaeochromocytomas and 26 had paragangliomas. Bilateral tumours were noted in eight of the patients and malignant tumours were seen in 13. Paragangliomas were often small, non-functional, and presented incidentally, whereas phaeochromocytomas were usually large, functional, and symptomatic. p53 overexpression, loss of Rb expression, and mdm2 overexpression were seen in four, 43, and 37 of the patients, respectively. Three of the four patients with p53 overexpression had bilateral tumours. Loss of Rb expression was often found in phaeochromocytomas, whereas mdm2 overexpression was more frequently seen in paragangliomas. The 10 year survival rate of patients with malignant tumours was 45%. Two patients died of tumour metastases more than 10 years after resection of the primary tumours. CONCLUSIONS: Phaeochromocytomas and paragangliomas had distinctive clinical features and genetic alterations. The prognosis of patients with these tumours was related to the malignant potential. p53 overexpression, more common in bilateral phaeochromocytomas and paragangliomas, could be a marker for this tumour subgroup.

Adolescent↗
PubMed2001

Adrenal lipomatous tumours: a 30 year clinicopathological experience at a single institution.

AIMS: Fatty tumours of the adrenal gland are uncommon and their features have received little attention in the literature. The aim of this study is to analyse the features of adrenal lipomatous tumours. METHODS: The histological features of primary adrenal tumours reported over a 30 year period (1970 to 1999) in Queen Mary Hospital, Hong Kong were reviewed and the clinicopathological features of adrenal lipomatous tumours were analysed. RESULTS: Adrenal lipomatous tumours were noted in 20 patients (12 men, eight women), and they accounted for 4.8% of the primary adrenal tumours reported. The adrenal fatty tumours comprised 11 myelolipomas, three lipomas, three teratomas, two angiomyolipomas, and one liposarcoma. Calcification or bone was noted in one third (seven of 20) of the adrenal tumours. In some fatty tumours (myelolipoma and angiomyolipoma), the fatty component may be inconspicuous. This is the first report in the English literature of angiomyolipoma and liposarcoma of the adrenal gland. CONCLUSIONS: Different types of fatty tumours were noted in the adrenal gland. A high index of suspicion should be maintained with an aim of surgical treatment for selected patients with large and symptomatic adrenal lipomatous lesions. Histological confirmation is needed for diagnosis.

Adolescent↗
PubMed2001

The clinicopathologic significance of p53 and p21 expression in the surgical management of lingual squamous cell carcinoma.

The aim of the present study was to evaluate the clinicopathologic significance of p53 and p21 expression in lingual squamous cell carcinomas. Immunohistochemical staining was performed with p53 and p21 monoclonal antibodies on surgical specimens from 87 patients who underwent primary surgical treatment for lingual carcinoma between 1976 and 1996. We found positive expression of p53 in 45 (52%) of 87 cases and of p21 in 49 (56%) of 87 cases. There was no correlation of p53 and p21 expression with cancer stage, T stage, nodal metastasis, and tumor grade. Univariate analysis revealed that p21 expression, tumor stage, T stage, and nodal stage were significant prognostic factors for survival. However, only p21 expression and tumor stage were significant independent prognostic factors for survival in a multivariate Cox regression analysis. Overexpression of p21 but not p53 has prognostic value for survival in the surgical treatment of lingual carcinomas. The combination of stage with p21 expression is recommended for evaluation of prognosis and for management planning.

Adult↗
PubMed2001

Morphological analysis of adrenal glands: a prospective analysis.

There is a lack of studies to document the weight range of normal adrenal glands. The aims of the current study are to find out the weight range of normal adrenal glands in Chinese patients and to analyze any potential factors affecting it. Adrenal glands not affected by disease were prospectively collected from autopsies on 333 Chinese patients (208 men, 125 women). The weight and longest dimension of each adrenal gland were noted. The impact of various clinicopathological factors on the adrenal weight was studied. In addition, the morphometric features of these adrenal glands were compared with that of 28 surgically resected adrenal glands with cortical adenomas. The mean combined weight of adrenal glands was 11.8 g (range = 5.8 g to 19.9 g). The left adrenal gland was often heavier than the right (mean weight = 6.1 g and 5.7 g respectively) and with a greater longitudinal length than the right (mean length = 5.2 cm and 4.8 cm respectively). Adrenal glands were often heavier in male, younger age group (less than 60-yr-old) and patients with history of hypertension or lung cancers. In comparison, the mean weight of right adrenal gland with cortical adenoma was 11.7 g (range = 6 g to 26 g) and that of left adrenal gland with cortical adenoma was 9.4 g (range = 4.6 g to 25 g). This is the first study in the English literature that provides data on the weight of normal adrenal glands in a solely Chinese population. Adrenal weight may be affected by patients' gender, age, laterality of adrenal gland and presence of systemic disease.

Adenoma↗
PubMed2001

Detection of genetic alterations in esophageal squamous cell carcinomas and adjacent normal epithelia by comparative DNA fingerprinting using inter-simple sequence repeat PCR.

In this study, we screened 19 esophageal squamous cell carcinomas (ESCCs) for the detection of genetic alterations using inter-simple sequence repeat PCR, a DNA fingerprinting approach. Three simple repetitive unanchored primers representing tri- and tetranucleotide repeats [(GTG)(5), (GACA)(4), and (GATA)(4)] were used, and evidence of gains and losses of chromosomal sequences were detected in all tumors (19 of 19 cases) for at least one of the primers. In 13 of these cases, apparently normal marginal epithelia adjacent to the tumors were also collected and examined. Eight of the 13 (62%) patients showed matching somatic mutations in the marginal epithelia adjacent to the tumors. Five of these 8 (63%) marginal epithelial samples were histologically normal, two were dysplastic, and one had extremely rare tumor cells. In 3 of these 13 (23%) cases, the profile bands were also seen to quantitatively increase in intensity, progressing from normal epithelia to marginal epithelia to tumors. Ten profile bands showing gains and one profile band showing loss in tumors compared with the corresponding normal epithelia were cloned, and their origins were determined by sequencing. The DNA sequence of one of the profile bands showing gain in the tumor could be matched to an expressed sequence tag sequence that has been mapped to the 7q22 region, a genomic amplification novel to ESCC. The sequence of the other profile band showing gain in the tumor could be matched to a nonexonic sequence of chromosome 20, whereas the sequences of the remaining profile bands could not be matched with any known sequences after comparison with the genomic sequence data in the European Molecular Biology Laboratory and GenBank databases. The bona fide nature of the gains or losses of 11 profile bands in the original cases was confirmed by direct genomic PCR amplification. The frequencies of these specific gene alterations in tumors were then analyzed in a total of 60 ESCCs, which included 41 additional cases of ESCC. Significantly, 26 of 60 (43%) tumors showed the DNA amplification for the expressed sequence tag sequence of chromosome 7, whereas the frequency of other individual gene alterations ranged from 7% to 15%. It is concluded that the inter-simple sequence repeat PCR strategy is adequate for the detection of somatic mutations in tumors, most of which are quantitative alterations in anonymous genomic sequences. This approach is also suitable for detection of somatic mutations preceding the onset of morphologically detectable neoplasia in ESCC.

Aged↗