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King Yin Lam

Publications and source records attributed to King Yin Lam.

11 recordsLinked to original sources
PubMed2005

Warthin tumor-like variant of papillary thyroid carcinoma: a case with dedifferentiation (anaplastic changes) and aggressive biological behavior.

Warthin tumor-like variant of papillary thyroid carcinoma is uncommon and approx 80 cases have been reported in the literature. This tumor is often associated with a favorable prognosis. In this report, a Warthin tumor-like variant of the papillary thyroid carcinoma, 5-cm in maximum dimension, underwent anaplastic changes in a 74-yr-old woman. The tumor was positive for CD15 and EMA, and a high proliferative index was noted in the anaplastic area. The patient developed distant metastases after operation and died of the disease 18 mo after the operation. The present case is the first reported case of Warthin tumor-like variant of papillary thyroid carcinoma with anaplastic changes.

Adenolymphoma↗
PubMed2002

Loss of E-cadherin expression resulting from promoter hypermethylation in oral tongue carcinoma and its prognostic significance.

BACKGROUND: E-cadherin is expressed on the surface of normal epithelial cells. Loss of E-cadherin expression has been found in cancers and is postulated to facilitate tumor cell dissociation and metastasis. This study evaluated the role of promoter dense methylation in the downregulation of E-cadherin expression in oral tongue carcinoma. METHODS: E-cadherin expression of 109 oral tongue carcinomas (93 primary tumors, 7 locally recurrent tumors, and 9 metastatic lymph nodes) was evaluated by immunohistochemical staining of tumor tissues. The methylation status of the CpG islands at the promoter region of E-cadherin which flanked five HpaII (methylation sensitive restriction enzyme) digestion sites were evaluated by methylation sensitive polymerase chain reaction in 86 tumors (70 primary tumors, 7 locally recurrent tumors, and 9 metastatic lymph nodes). RESULTS: Underexpression of E-cadherin was found in 83% of primary tumors, 86% of recurrent tumors, and 89% of nodal metastases. Hypermethylated E-cadherin promoter was found in 64% of primary tumors, 71% of recurrent tumors, and 67% of nodal metastases. Downregulation of E-cadherin expression was found to be related to promoter hypermethylation. Consistently weak expression of E-cadherin by promoter hypermethylation was observed in primary tumors, their corresponding metastatic lymph nodes, and recurrent tumors. Downregulation of E-cadherin expression was a significant poor prognostic factor for survival. CONCLUSIONS: Methylation of CpG sites at the promoter region played a key role in the inhibition of E-cadherin expression in both primary oral tongue carcinomas and their corresponding recurrences and nodal metastases. The resulting downregulation of E-cadherin expression had adverse effects on the prognosis of patients who were treated by primary surgery.

Cadherins↗
PubMed2002

Neurothekeoma of the paranasal sinuses in a 3-year-old boy.

Neurothekeoma is a benign soft tissue tumor commonly located on the skin. In this report, a 3-year-old boy presented with restricted right eye movement and decrease in visual acuity. The patient was found to have a 6-cm neurothekeoma involving the maxillary and ethmoid sinuses. To our knowledge, this is the first reported case of neurothekeoma with involvement of the maxillary and ethmoid sinuses. This uncommon lesion should be considered as the differential diagnosis of pediatric soft tissue tumors in the head and neck region.

Biopsy, Needle↗
PubMed2002

Prognostic factors of clinically stage I and II oral tongue carcinoma-A comparative study of stage, thickness, shape, growth pattern, invasive front malignancy grading, Martinez-Gimeno score, and pathologic features.

PURPOSE: This study aims at evaluation of the different prognostic models, including stage, tumor thickness, shape, malignancy grading of tumor invasive front, Martinez-Gimeno score, and pathologic features in the prediction of subclinical nodal metastasis, local recurrence, and survival of early T1 and T2 oral tongue squamous cell carcinoma. The results will have important implication for the management of patients. PATIENTS AND METHODS: Seventy-two clinically T1 and T2 glossectomy specimens of oral tongue carcinoma were serially sectioned in 3-mm thickness for the evaluation of various pathologic features. The prognostic value in the prediction of subclinical nodal metastasis, local recurrence, and survival of different models were compared. RESULTS: Among all the tumor parameters and predictive models being evaluated, tumor thickness was the only significant factor that had significant predictive value for subclinical nodal metastasis, local recurrence, and survival. With the use of 3-mm and 9-mm division, tumor of up to 3-mm thickness has 8% subclinical nodal metastasis, 0% local recurrence, and 100% 5-year actuarial disease-free survival; tumor thickness of more than 3 mm and up to 9 mm had 44% subclinical nodal metastasis, 7% local recurrence, and 76% 5-year actuarial disease-free survival; tumor of more than 9 mm had 53% subclinical nodal metastasis, 24% local recurrence, and 66% 5-year actuarial disease-free survival. CONCLUSIONS: Tumor thickness should be considered in the management planning of patients with early oral tongue carcinoma.

Adolescent↗
PubMed2002

Specialized intestinal metaplasia and carditis at the gastroesophageal junction in Chinese patients undergoing endoscopy.

OBJECTIVE: Specialized intestinal metaplasia (SIM) is often found at a normal-looking gastroesophageal junction on routine biopsy. The prevalence of SIM in Asian populations has not been recorded. Its significance is also unclear. The objective of the study was to document the prevalence of SIM at the gastroesophageal junction in a Chinese population undergoing endoscopy. METHODS: Biopsies were taken at the gastroesophageal junction in 145 patients, both at the squamocolumnar junction and immediately below in the gastric cardia. Specimens were examined for the type of epithelium (squamous, cardiac, and fundic), the presence of SIM, and Helicobacter pylori (H. pylori). RESULTS: Of 145 patients who underwent endoscopy, 136 had a normal-looking gastroesophageal junction. Cardiac epithelium was found in 100 patients. Of these 100 patients, SIM was documented in 34% of patients and carditis in 20%. Patients with SIM were older compared with those without SIM (mean age 62 yr and 56 yr, p = 0.035). Carditis was more prevalent in patients with SIM. It was present in 11 out of 34 patients who had SIM (32.4%) compared with nine in 66 patients (13.6%) without SIM, p = 0.036. When carditis was found, H. pylori was present at the cardia in 40% of patients (eight of 20) compared with only 18% (14 of 80) in those without carditis, p = 0.039. CONCLUSIONS: SIM is prevalent at the gastroesophageal junction in Chinese patients undergoing endoscopy and is associated with carditis. Carditis in turn may be related to H. pylori infection.

Adult↗
PubMed2002

Regulation and expression of a renin-angiotensin system in human pancreas and pancreatic endocrine tumours.

OBJECTIVE: Evidence exists for the presence of a renin-angiotensin system (RAS) in the pancreas. The aims of this study were to prove the presence of an intrinsic RAS in the human pancreas and to analyse the role of such an RAS in pancreatic endocrine tumours (PETs). METHODS: Gene expression of key RAS components (angiotensinogen and angiotensin II receptors, namely AT1 and AT2) was investigated in human pancreas and in PETs by semi-quantitative RT-PCR and immunohistochemistry. RESULTS: Expression of mRNAs of RAS components was found in human pancreas and in PETs. Data from semi-quantitative RT-PCR analysis demonstrated an increase in the mRNA expression of angiotensinogen and AT2 receptor in PETs when compared with that in normal pancreas. By immunohistochemistry, angiotensinogen protein was predominantly localized in the pancreatic islets while AT1 receptor protein was in the pancreatic ducts. CONCLUSIONS: The data support the notion of the existence of an intrinsic RAS in the human pancreas. It also indicates, for the first time, that such a local pancreatic RAS is subject to regulation by PETs and its significant change may have pathophysiological relevance in patients with PETs.

Angiotensinogen↗
PubMed2002

High prevalence of RET proto-oncogene activation (RET/PTC) in papillary thyroid carcinomas.

OBJECTIVE: The activation of RET proto-oncogene, through different types of chromosomal translocation and inversion, is unique to papillary thyroid carcinomas (PTC) and its frequency is variable in different populations. The aim of this study was to investigate the frequency and types of PTC genetic rearrangements in papillary carcinoma in a population of Hong Kong Chinese. METHODS: The presence of RET/PTC1, RET/PTC2 and RET/PTC3 activation was analyzed by RT-PCR in twenty PTC from adult patients (age range 24-63 years), one PTC from a 12-year-old boy and anaplastic carcinomas in two adult patients. RESULTS: RET/PTC3 was the only activation of RET proto-oncogene identified in the samples. Seventeen PTC from adult patients (85%t) were positive for RET/PTC3. RET/PTC3 was also identified in PTC from the child and one of the two patients with anaplastic thyroid carcinoma. CONCLUSIONS: The prevalence of RET/PTC activation in PTC is high and RET/PTC3 is the only type of activation identified in Hong Kong Chinese and is an important genetic event underlying the development of PTC in the population.

Adult↗