Lai Kun Lam

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

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.

Salvage of recurrent head and neck squamous cell carcinoma after primary curative surgery

The efficacy of salvage treatment of recurrent head and neck squamous cell carcinomas (HNSCC) after primary curative surgery was evaluated.

Irradiation-induced extracranial carotid stenosis in patients with head and neck malignancies

BACKGROUND Carotid stenosis is a recognized complication of external irradiation to the head and neck for malignancy. This study aim to investigate the pattern and prevalence of radiation induced carotid disease, and to identify risk factors associated with significant stenosis. METHODS In a comparative cross-sectional study, carotid arteries color flow duplex scan was performed on 240 patients who had received external irradiation to the head and neck area, with a mean interval of 72 months from radiotherapy. They consisted of 181 men and 59 women, with a mean age of 59 years. Fifteen patients had a history of cerebrovascular symptoms. RESULTS Internal carotid artery (ICA) stenosis of 70% or greater was detected in 29 arteries in 24 patients. Common carotid artery (CCA) disease of > or =70% was present in 13 arteries in 12 patients. Overall 28 patients had significant ICA/ CCA disease (11.7%). Patients with nasopharyngeal and laryngeal carcinoma had more cerebrovascular symptoms, and more frequent CCA stenosis. Significant ICA/CCA stenosis was associated with age, smoking, coronary heart disease, stroke, no head and neck surgery, time interval from radiotherapy, and the site of primary tumor. On logistic regression analysis age (>60 years), cerebrovascular symptoms, interval from irradiation (>5 years), and nasopharynx and larynx cancer were found to be independent significant (P<0.05) predictors of 70% or greater ICA/CCA stenosis. CONCLUSIONS Patients who had received radiotherapy to the head and neck have a high risk of developing significant carotid stenosis. Routine duplex ultrasound screening in these patients is indicated.

Clinicopathological analysis of local spread of carcinoma of the tongue

BACKGROUND The aims of the study are three-dimensional analysis of mode and distance of local spread of oral tongue carcinoma. METHODS The glossectomy specimens were examined in the coronal plane in 3 mm thickness section. RESULTS There were 50 glossectomy specimens. The maximum spread was 1.8 cm. Ninety-six percent of specimens had local spread within 1.2 cm. The distance of spread was not correlated with tumor size, including the diameter, depth, and volume. The incidence of local recurrence was 27% with positive histological margin. Perineural infiltration was the most important prognostic factor for local recurrence and survival. CONCLUSIONS A minimum of 1.5-cm surgical resection margin is recommended. A smaller margin is not recommended as it has significant risk of local recurrence. A maximum of 2-cm surgical resection margin is recommended; larger margins will increase the surgical morbidity without a significant advantage of local control.

Current status of pharyngolaryngo-esophagectomy and pharyngogastric anastomosis

Pharyngolaryngo‐esophagectomy and pharyngogastric anastomosis (PLO & PGA) is one of the surgical options in the management of tumors arising from the hypopharynx and cervical esophagus. Indications of the operation and the outcome are changing over the years. To examine these, the experience of this operation in one Institute (the Head and Neck Division of the Department of Surgery, The University of Hong Kong at Queen Mary Hospital, Hong Kong) over the last 30 years was reviewed.

Cervical lymph node metastatic patterns of squamous carcinomas in the upper aerodigestive tract

The radical neck dissection specimens of 384 ethnically Chinese patients with different primary squamous carcinomas in the head and neck region were studied. Over 50 per cent of the specimens showed metastatic disease at one level in the neck. For oral cavity carcinoma, the levels of metastasis frequently involved were I, II and III while for carcinoma of the oropharynx, hypopharynx and larynx the levels were II, III and IV. Extracapsular spread was present in 112/384 of patients (29 per cent) and this increased with advancing N-stages. Based on these findings, different selective neck dissections could be used for patients harbouring different primary head and neck carcinomas with limited neck disease.

Thoracoscopic esophageal mobilization for pharyngolaryngoesophagectomy

BACKGROUND Pharyngolaryngoesophagectomy (PLE) for hypopharyngeal cancers and tumors of the cervical esophagus is a procedure of significant morbidity and mortality. Conventional esophageal mobilization is performed with the transhiatal dissection technique. Thoracoscopic esophageal mobilization is tested as an alternative to determine whether surgical outcome can be improved. METHODS From 1994 to 1998, thoracoscopic mobilization was carried out in 30 consecutive patients who underwent PLE (PLE-TS). This was compared to a historical cohort of 30 patients who had PLE with transhiatal mobilization (PLE-TH). RESULTS In PLE-TS, thoracoscopic esophageal mobilization was successful in 28 patients (93%). Median blood loss was 700 mL (range, 164 to 3,000 mL) compared to 1,000 mL (range, 400 to 2,200 mL) in group PLE-TH, p = 0.21. Thoracoscopy time was 90 minutes (range, 60 to 180 minutes). Total operating time were 392 minutes (range, 180 to 570 minutes) and 300 minutes (range, 150 to 550 minutes) in PLE-TS and PLE-TH, respectively (p = 0.03). Major pulmonary complications occurred in 7 (23%) and 8 (27%) patients in PLE-TS and PLE-TH, respectively (p = 0.77). Cardiac complications occurred in 7 (23%) and 5 (17%) patients in PLE-TS and PLE-TH, respectively (p = 0.52). Thirty-day mortality rates were 3.3% and 10% (p = 0.6) and hospital mortality rates were 13% and 17%, (p = 1.0). CONCLUSIONS Thoracoscopy was safe and feasible. Morbidity and mortality after PLE was not significantly reduced. The theoretical advantage offered by thoracoscopy may be offset by the lengthened time of one-lung anesthesia.

Primary Closure of Pharyngeal Remnant After Total Laryngectomy and Partial Pharyngectomy: How Much Residual Mucosa Is Sufficient?

After total laryngectomy with or without partial pharyngectomy, the remaining pharyngeal defect can be repaired either by primary closure or with additional tissue, depending on the amount of pharyngeal tissue remnant available. The aim of this study was to determine the minimum width of the pharyngeal remnant that could be safely closed primarily without causing difficulty in swallowing.

Lymphoepithelioma-like carcinoma of the skin

The histopathological findings of two cases of primary lymphoepithelioma-like carcinoma (LELC) of the skin occurring in two elderly Chinese individuals are presented. Microscopically, they were well circumscribed and were composed of irregular nests of malignant epithelial cells in a background of reactive lymphoid cells including mature plasma cells. A focus of epithelial dysplasia was noted in the adjacent epidermis in one case, suggesting that the LELC might have originated from the overlying epidermis. The epithelial nature of the tumors was confirmed by cytokeratin staining. In situ hybridization for Epstein-Barr virus-encoded RNA (EBER) showed that the tumor cells were uniformly negative, although positive signals were detected in scattered background lymphocytes in case 1. Our results confirm the previous observation that LELC of skin is not related to Epstein-Barr virus, even in Chinese subjects. Nevertheless, such negative findings may prove to be of diagnostic value in excluding the alternative more common diagnosis of metastatic nasopharyngeal carcinoma, which is uniformly positive for EBER.

Mucosal Changes of the Free Jejunal Graft in Response to Radiotherapy

BACKGROUND Microvascular free jejunal transfer was employed for reconstruction of pharyngeal defect resulting from circumferential resection of the hypopharynx. Postoperative radiotherapy to the neck might affect the graft, but this information was lacking. The mucosal changes of the jejunum in response to radiation were identified in this prospective study. METHODS Normal jejunal mucosa was obtained at operation, and endoscopic jejunal mucosal biopsies were taken during and at completion of radiotherapy. Endoscopic biopsies were repeated at 1, 3, 6, 12, and 24 months afterwards. All jejunal biopsies were subjected to histologic and scanning electron microscopic (SEM) examinations. Nine patients had a complete set of biopsy while 5 other patients who received no radiotherapy also went through a similar sequence of biopsies as controls. RESULTS Histologic examination showed mucosal edema and extensive blunting of jejunal villi at the completion of radiotherapy. Increased fibrosis with focal loss of glands was noticed at 3 months after radiotherapy, and this remained throughout the 2-year period. SEM revealed patchy loss of microvilli at completion and at 1 month after radiotherapy, but this feature was not apparent in biopsies taken at 3 months onwards, showing that it was only a transient event. CONCLUSIONS Transient responses and persistent changes of jejunal mucosa to radiotherapy were identified and characterized. The presence of these mucosal lesions was not associated with any clinically significant adverse effect in the graft up to 2 years postradiotherapy.