George K. H. Li

Epigenetic Inactivation of the miR-124-1 in Haematological Malignancies

miR-124-1 is a tumour suppressor microRNA (miR). Epigenetic deregulation of miRs is implicated in carcinogenesis. Promoter DNA methylation and histone modification of miR-124-1 was studied in 5 normal marrow controls, 4 lymphoma, 8 multiple myeloma (MM) cell lines, 230 diagnostic primary samples of acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL), chronic myeloid leukaemia (CML), chronic lymphocytic leukaemia (CLL), MM, and non-Hodgkins lymphoma (NHL), and 53 MM samples at stable disease or relapse. Promoter of miR-124-1 was unmethylated in normal controls but homozygously methylated in 4 of 4 lymphoma and 4 of 8 myeloma cell lines. Treatment of 5-Aza-2′-deoxycytidine led to miR-124-1 demethylation and re-expression of mature miR-124, which also associated with emergence of euchromatic trimethyl H3K4 and consequent downregulation of CDK6 in myeloma cells harboring homozygous miR-124-1 methylation. In primary samples at diagnosis, miR-124-1 methylation was absent in CML but detected in 2% each of MM at diagnosis and relapse/progression, 5% ALL, 15% AML, 14% CLL and 58.1% of NHL (p<0.001). Amongst lymphoid malignancies, miR-124-1 was preferentially methylated in NHL than MM, CLL or ALL. In primary lymphoma samples, miR-124-1 was preferentially hypermethylated in B- or NK/T-cell lymphomas and associated with reduced miR-124 expression. In conclusion, miR-124-1 was hypermethylated in a tumour-specific manner, with a heterochromatic histone configuration. Hypomethylation led to partial restoration of euchromatic histone code and miR re-expression. Infrequent miR-124-1 methylation detected in diagnostic and relapse MM samples showed an unimportant role in MM pathogenesis, despite frequent methylation found in cell lines. Amongst haematological cancers, miR-124-1 was more frequently hypermethylated in NHL, and hence warrants further study.

Prospective randomized study of selective neck dissection versus observation for N0 neck of early tongue carcinoma

There are controversies on the benefits of elective neck dissection (END) for oral tongue carcinoma.

The role of fine‐needle aspiration cytology in the management of parotid tumors: A critical clinical appraisal

Fine‐needle aspiration cytology (FNA) is a well‐established tool for investigating many head and neck conditions. It application in parotid tumors is, however, very controversial. This article is aimed at defining the exact role of FNA in the diagnostic workup of patients.

Extracranial head and neck schwannomas: a study of the nerve of origin

Schwannoma is a type of benign nerve sheath tumour arising from the Schwann cell. Because of the close relationship between the tumour and the nerve of origin (NOO), the operation of extracranial head and neck schwannoma may lead to palsy of major nerve. For this reason, an accurate diagnosis of schwannoma with the identification of the NOO is crucial to the management. The aim of this review was to find out the distribution of the NOO and the usefulness of the investigations in the diagnosis of schwannoma. Medical records of the patients who underwent operation of the extracranial head and neck schwannoma in our division were reviewed. Between January 2000 and December 2009, 30 cases of extracranial head and neck schwannoma were operated. Sympathetic trunk (10, 33%) and vagus nerve (6, 20%) were the two most common NOOs. In five (17%) cases, the NOO was not found to be arising from any major nerve. For these 30 patients, 20 received fine needle aspiration cytology (FNAC) and 26 underwent imaging studies (computed tomography or magnetic resonance imaging) before operation. The specificity of FNAC and imaging studies in making the diagnosis of schwannoma was 20 and 38%, respectively. For the patients who had nerve palsies on presentation, their deficits remained after operation. The rate of nerve palsy after tumour excision with division of NOO and intracapsular enucleation was 100 and 67%, respectively. The diagnosis of schwannoma is suggested by clinical features and supported by investigations. Most of the time, the diagnosis can only be confirmed on the histological study of the surgical specimen. Sympathetic trunk and vagus nerve are the two common NOOs. MRI is the investigation of choice in the diagnosis of schwannoma and the identification of NOO.

Extramammary Paget’s Disease: 20 Years of Experience in Chinese Population

Background. To examine the results of treatment of Extramammary Pagets disease (EMPD) in ethnic Chinese. Method. Between 1990 and 2010, patients treated for EMPD were reviewed. Data were analyzed retrospectively. Results. Forty-eight patients were treated by surgical resection. Local recurrence rate was 14.6%. The postresection defects were repaired by primary closure (8.3%), partial thickness skin graft (72.9%), or local/regional flaps (18.8%). Dermal invasion was found in 9 patients (18.8%). Seven patients (14.6%) developed regional lymph node metastasis (concurrent with surgery, n = 1; subsequent to surgery, n = 6), and 3 patients (6.3%) had systemic metastasis after surgery. The presence of dermal invasion was associated with significantly higher incidence of regional lymph nodes and systemic metastasis. The incidence of associated internal malignancy was 8.3%. Conclusion. The mainstay of treatment for EMPD is surgery. Pathological dermal invasion increases the chance of regional lymph node as well as systemic metastasis. The association with internal malignancy warrants preoperative endoscopic examination in all patients.

Aesthetic considerations in the cervicofacial management of Madelung syndrome

The most common concern in patients with Madelung syndrome who are seeking cosmetic improvement is the deposition of fat in the cervicofacial region. Surgical experience in a series of 15 patients was summarised to provide guidelines for a rational approach to a better aesthetic outcome. The records and clinical photographs of these patients were reviewed. Outcome was assessed in terms of adequacy of debulking, final overall symmetry, smoothness of contour, prominence of scar, and necessity for multiple sessions. Open excision was the preferred primary treatment. A long mid-neck, transverse skin crease incision provided good exposure and was superior to multiple local incisions. Other surgical details worth noting include subplatysmal dissection, thick skin flaps, dissection around instead of into lipomas, appropriate removal of redundant skin, adequate reduction of tumour size instead of total excision, haemostasis, suction drainage, and layered skin closure. Liposuction was a useful adjunct for contouring the sides of the jaws in selected patients.

Fat grafting: A safe and effective treatment of craniofacial depression

Many techniques have been described to correct craniofacial depression defect to achieve satisfactory result but they involve complicated reconstruction and considerable donor site morbidities. The result of fat grafting in correction of the defects is demonstrated in this study.

FACTORS AFFECTING FALSE-NEGATIVE BREAST SENTINEL NODE BIOPSY IN CHINESE PATIENTS*

Background:  The objective of the research was to validate our results on sentinel lymph node biopsy (SLNB) and to determine factors affecting false‐negative (FN) rates of SLNB in Chinese patients with invasive breast cancers.