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Chung Yau Lo

Publications and source records attributed to Chung Yau Lo.

11 recordsLinked to original sources
PubMed2006

Clinicopathological roles of alterations of tumor suppressor gene p16 in papillary thyroid carcinoma.

BACKGROUND: Alterations of the p16 gene are common in human cancers, but their roles in thyroid cancers have not been clearly defined. The aim of the present study was to investigate the clinicopathological roles of the p16 gene in papillary thyroid carcinoma (PTC). METHODS: p16 gene alterations were investigated in 44 patients with PTC (9 men, 35 women) by immunohistochemistry, reverse transcriptase-polymerase chain reaction and methylation-specific polymerase chain reaction. The findings were correlated with their clinicopathological features. RESULTS: p16 protein expression, mRNA alterations, and promoter methylation were detected in 89% (n = 39), 77% (n = 33), and 41% (n = 18) of patients with PTC, respectively. There was no marked relationship between p16 protein expression, mRNA alteration, and promoter methylation. In follicular variant of PTC (FVPTC), there was a frequent lack of p16 protein expression and promoter methylation. PTCs showing p16 promoter methylation were often associated with a high AMES (age, metastasis to distant sites, extrathyroidal invasion, size) risk group and advanced pTNM (tumor-lymph node-metastasis) stages. CONCLUSIONS: p16 gene alterations are common and correlate with histological features and biological aggressiveness in PTC, suggesting that they might play an important role in its pathogenesis.

Adenocarcinoma, Follicular↗
PubMed2006

Diffuse sclerosing variant of papillary carcinoma of the thyroid: a 35-year comparative study at a single institution.

BACKGROUND: Diffuse sclerosing variant (DSV) is a rare variant of papillary thyroid carcinoma (PTC), and the features of this carcinoma have not been fully characterized. The aim of this study was to analyze the clinicopathologic features of a large cohort of patients with this disease. METHODS: We reclassified primary thyroid carcinomas treated in a 35-year study period and studied the clinicopathologic features and outcomes of DSV of PTC in comparison with classic PTC. RESULTS: Fifteen patients (2 men and 13 women) with DSV of PTC were identified who had surgical resection of the thyroid. Fine-needle aspiration biopsy diagnosed 83% (10 of 12) of the tumors. Compared with classic PTC, patients with DSV presented at a younger age (mean age, 29 vs. 46 years; P = .0001), had larger tumors (mean diameter, 3.6 vs. 2.2 cm; P = .002), and had a higher incidence of cervical nodal metastases (80% vs. 43%; P = .006). Ten patients had received postoperative iodine 131 ablation, and four had also received external-beam irradiation. Distant metastases were detected in two patients (one in lung and one in brain). One third (5 of 15) of the patients developed disease recurrence. Lymph node recurrence was detected in one patient 12 years after the initial operation. Over a median follow-up period of 10.7 years, one patient with an initial incomplete excision died of the carcinoma. The overall disease-specific survival rate was 93%. CONCLUSIONS: DSV of PTC had distinctive clinicopathologic features and a high incidence of recurrence after operation but had a prognosis similar to that of classic PTC.

Adolescent↗
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↗
PubMed2003

Applicability and outcome of laparoscopic adrenalectomy.

Laparoscopic adrenalectomy has been shown to be as safe and effective as conventional open surgery for small and benign adrenal lesions. With increasing experience with laparoscopic adrenalectomy, this approach has become the procedure of choice for the majority of patients requiring adrenalectomy, although careful selection of patients accounts for the favourable clinical outcome observed. Laparoscopic adrenalectomy was adopted as the procedure of choice for patients requiring adrenalectomy in our institution in 1995. From 1995 to 2001, 82 consecutive patients underwent adrenalectomies for various adrenal pathologies. The laparoscopic approach was used for 60 of these patients, whose selection was based on the preoperative size and/or benign nature of the adrenal lesion. The procedures were successfully performed in 57 patients (54 unilateral, 3 bilateral), while three (5%) patients required conversion to open surgery. There was no hospital mortality and complications occurred in two (3%) patients. The median hospital stay was 3 days (range, 2-8 days) and analgesic requirement was minimal. Laparoscopic adrenalectomy can be done for all patients with small and benign adrenal pathologies, and has become the gold standard for patients undergoing adrenalectomies. When successfully performed, the laparoscopic approach offers the advantages of a minimally invasive procedure with improved patient comfort and faster postoperative recovery.

Adolescent↗
PubMed2002

Applicability of intraoperative parathyroid hormone assay during thyroidectomy.

OBJECTIVE: To evaluate the applicability of intraoperative parathyroid hormone (quick PTH) assay to monitor parathyroid function and to identify clinically significant hypocalcemia compared with postoperative serum calcium monitoring. SUMMARY BACKGROUND DATA: Close monitoring of serum calcium levels is a standard of care to identify post-thyroidectomy hypocalcemia due to parathyroid insufficiency. METHODS: Quick PTH assay was performed before and after thyroidectomy for 100 patients at risk of postoperative hypocalcemia and 20 control patients who underwent unilateral lobectomy. Postoperative serum calcium levels were closely monitored. RESULTS: Control patients had a normal but 38.9 +/- 5.9% (mean +/- SEM) decline in quick PTH after thyroidectomy. Eleven of 100 at-risk patients (11%) developed postoperative hypocalcemia. Hypocalcemic patients had significantly lower quick PTH values after thyroidectomy compared with that of normocalcemic patients. Serum calcium was significantly lower in hypocalcemic patients the morning after operation but not early after the operation (within 6 hours). A normal or less than 75% decline in quick PTH after thyroidectomy can accurately identify normocalcemic patients during surgery as compared to more than 24 hours by serum calcium monitoring. CONCLUSIONS: The quick PTH assay can monitor parathyroid function during thyroidectomy and identify patients at risk of clinically significant hypocalcemia much earlier than serum calcium monitoring. It may facilitate early discharge and the use of parathyroid autotransplantation during thyroidectomy.

Adult↗
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↗
PubMedDate not supplied

A comparative study of routine laparoscopic versus open appendectomy.

OBJECTIVE: We evaluated the outcomes of routine laparoscopy and laparoscopic appendectomy (LA) in patients with suspected appendicitis. This is a retrospective study of the outcomes of patients undergoing laparoscopic appendectomy compared with outcomes for patients undergoing open appendectomy (OA) during the time that LA came into use. METHOD: Results of patients managed with routine laparoscopy and LA for suspected acute appendicitis were reviewed and analyzed. The preoperative and intraoperative findings were recorded. The clinical outcomes were compared with those of patients undergoing OA in the preceding 10 months. RESULTS: During the LA study period, 97 patients (47 men) with the median age of 34 years (range, 18 to 79) presented with clinical features of acute appendicitis. With the exclusion of 5 patients with open operations and 10 patients with other pathologies, 82 patients underwent laparoscopic appendectomy (Group A) for appendicitis. Thirty-one (37.8%) patients had complicated appendicitis (perforated or gangrenous appendicitis). Conversions were required in 6 patients (7.3%). During the OA period, 125 patients (57 men) with the median age of 42 (range, 19 to 79) years were operated on. With the exclusion of 6 patients with other pathologies, 119 underwent OA for acute appendicitis (Group B). Fifty-one (42.9%) had either perforated or gangrenous appendicitis. The median durations of surgery in Group A and Group B were 80 minutes (range, 40 to 195) and 60 minutes (range, 25 to 260), respectively (P < 0.005). Postoperative complication rates were comparable between the 2 groups (13.4% in Group A versus 15.8% in Group B). The median hospital stay for patients in Group A and Group B were 3.0 days (range, 1 to 47) and 4.0 days (range, 1 to 47), respectively (P = 0.037). CONCLUSIONS: We conclude that routine laparoscopy and LA for suspected acute appendicitis is safe and is associated with a significantly shorter hospital stay. Other intra-abdominal pathologies can also be diagnosed more accurately with the laparoscopic approach.

Adolescent↗