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Ka-Wo Lee

Publications and source records attributed to Ka-Wo Lee.

31 records · Page 2Linked to original sources
PubMed2004

Fibro-osseous lesion of the external auditory canal: a case report.

The aim of this study was to differentiate a novel type of benign circumscribed bone lesion of the external auditory canal from lesions described previously, such as exostoses and osteomas. We present a 43-year-old male patient who suffered from ear discharge of the right ear. Local findings showed bloody discharge from his right auditory canal, which was occupied by a mass-like tissue. Computerized tomography (CT) carried out before resection of the lesion disclosed the absence of a bony connection to the underlying structures. The pathologic findings showed lesions consisting of an osteoma-like bone formation with sparse osteoblastic areas. Mature lamellar bone and bone marrow containing adipose tissue were also noted. There was no evidence of a relationship to the cartilaginous tissue or bony structures of the external auditory canal. Therefore, we present this rare case and review the reported literature in which clinical, CT, surgical, and pathologic findings suggest that this lesion was unlike those previously known, and may be related to ossifying reactions in other parts of the organism.

Adult↗
PubMed2004

Cerebral radionecrosis with cystic degeneration following radiotherapy for nasal cavity squamous cell carcinoma: a case report.

A 31-year-old man with nasal cavity squamous cell carcinoma was treated in our hospital with two courses of radiotherapy (120 Gy total dose) followed by surgical tumor resection. Three years after the last irradiation, he developed seizures as well as changes in behavior and consciousness. Medical therapy with diphenylhydantoin (Dilantin) terminated the seizures. Dysphagia, unsteady gait, and right-side limb weakness developed 37 months after the onset of seizures. Magnetic resonance imaging showed a large, cystic mass in the left temporal lobe with left to right midline shift. Following craniotomy with decompression of the cystic mass, the patient improved clinically. No malignant cells were found in the specimen. No further progression of neurologic symptoms was noted after a 1-year follow-up. Cerebral radionecrosis is an uncommon late complication of radiotherapy and needs to be differentiated from tumor recurrence or metastasis if the irradiation field covers the cerebral region in patients with head and neck malignancies.

Adult↗
PubMed2004

Risk of vocal palsy after thyroidecitomy with identification of the recurrent laryngeal nerve.

The purpose of this study was to assess the risk of vocal palsy after thyroidectomy with identification of recurrent laryngeal nerve (RLN) during surgery. In all, 521 patients treated by the same surgeon were enrolled in this study. Temporary and permanent vocal palsy rates were analyzed for patient groups classified according to surgery for primary benign thyroid disease, thyroid cancer, Graves' disease, and reoperation. Measurement of the vocal palsy rate was based on the number of nerves at risk. Twenty-six intentionally sacrificed RLNs were excluded from analysis. Forty patients developed postoperative unilateral vocal palsy. Complete recovery of vocal palsy was documented for 35 of the 37 patients (94.6%) whose RLN integrity had been ensured intraoperatively. Recovery from temporary vocal palsy ranged from 3 days to 4 months (mean, 30.7 days). The overall incidences of temporary and permanent vocal palsy were 5.1% and 0.9%, respectively. The rates of temporary/permanent vocal palsy in groups classified according to underlying disease were 4.0%/0.2% for benign thyroid disease, 2.0%/0.7% for thyroid cancer, 12.0%/1.1% for Graves' disease, and 10.8%/8.1% for reoperation. Surgery for thyroid cancer, Graves' disease, and recurrent goiter were associated with significantly higher vocal palsy rates. Most patients without documented nerve damage during the operation recovered from postoperative vocal palsy. Total lobectomy with routine RLN identification is recommended as a basic procedure in thyroid surgery.

Adolescent↗
PubMed2004

A long-term study on hearing status in patients with nasopharyngeal carcinoma after radiotherapy.

OBJECTIVE: To study the long-term sensorineural hearing status after radiotherapy in patients suffering from nasopharyngeal carcinoma. STUDY DESIGN: A prospective study of 220 patients (395 ears) with a median follow-up of 36 months. SETTING: A university hospital. PATIENTS: Four criteria were needed. The patient had to have had at least 12 months of audiologic follow-up, no concurrent chronic ear disease, no direct tumor invasion of ear, and no significant sensorineural hearing loss before radiotherapy. INTERVENTION: Pure-tone audiography and impedance audiometry-which were performed before and at the third month after completion of radiotherapy and at a yearly interval thereafter-formed the basis of the study. MAIN OUTCOME MEASURES: The significance level in this study was defined as a bone conduction threshold increase of more than 10 dB between the initial audiogram and those obtained after the completion of radiotherapy. An increase of more than 30 dB was defined as severe loss. RESULTS: Paired t test indicated that the mean bone conduction threshold before and after radiotherapy were significantly different (paired t test, p < 0.05). Logistic regression showed that patient age was related to the significant loss at speech frequency but not to the loss at 4 kHz. The presence of postradiation otitis media with effusion, preirradiation hearing status, and addition of chemotherapy were found to be not influential on hearing change. CONCLUSION: Hearing deterioration may begin as early as 3 months after the completion of radiotherapy. Early change may be transient, but the effect of radiation on hearing tended to be chronic and progressive.

Acoustic Impedance Tests↗
PubMed2004

Microsurgical pressing excision technique for vocal nodules and simple epithelial hyperplasia of the vocal fold.

Precise bimanual microsurgical excision of sessile, thin benign epithelial lesions of the vocal folds can be difficult. During microlaryngeal surgery, the potential risks of over-excision and under-excision are of major concern. We introduce a microsurgical technique using horizontally-opening curved microforceps and microscissors, instead of the conventional vertically-opening microinstruments, to remove vocal nodules and simple epithelial hyperplasia. The treatment results were satisfactory, with 208 (90.8 per cent) of patients retaining a satisfactory/normal (G(0)) voice. No patient had a worsened voice after the procedure. This microsurgical pressing excision technique is an alternative precise method for microlaryngosurgery.

Epithelium↗
PubMed2003

Hearing loss in patients with nasopharyngeal carcinoma after chemotherapy and radiation.

In light of the possible adverse effects of radiation on hearing, we conducted a study to evaluate the long-term sensorineural hearing status following radiotherapy (RT) in patients suffering from nasopharyngeal carcinoma. Audiologic examinations were performed at regular intervals before and after RT. We also analyzed the effects of age, chemotherapy, pre-RT hearing status, and post-RT otitis media with effusion (OME) on post-RT hearing change. A total of 150 patients (261 ears) were enrolled in this study and followed up for a mean of 43.8 months. After RT, 8.9-28.8% of ears had at least a 10 dB loss in bone conduction threshold at speech frequency, which was defined as an average of hearing threshold at 0.5 kHz, 1 kHz, and 2 kHz, while the percentage was 18-34.2% at 4 kHz. Patient age was related to these changes at speech frequency, and the presence of post-RT OME was related to significant loss at both speech frequency and 4 kHz. Pre-RT hearing status and chemotherapy did not influence hearing change. To sum up, sensorineural hearing loss began as early as after completion of RT. Early changes may be transient, but the effect of radiation on hearing tended to be chronic and progressive.

Adolescent↗
PubMed2003

Expression of epidermal growth factor receptor in human middle ear cholesteatoma.

Middle ear cholesteatoma is destructive to auditory ossicles and temporal bone, and treatment usually includes surgical removal of all epithelial content in the tympanomastoid cavity. Epidermal growth factor receptor (EGFR) is a 170 kd to 180 kd transmembrane glycoprotein and its distribution density is related to the ability of the keratinocytes to differentiate and their state of differentiation. We used the avidin-biotin complex technique and EGFR monoclonal antibody to evaluate the expression of EGFR in 29 cases of cholesteatoma and 34 samples of normal postauricular skin. Of patients with cholesteatoma, 79% (23 cases) had EGFR-positive cells in the basal layer, 66% (19 cases) in the parabasal layer, and 62% (18 cases) in the upper layer of the epithelial tissue. Among patients with normal postauricular skin, 85% (29 cases) had EGFR-positive cells in the basal layer, 79% (27 cases) in the parabasal layer, and 79% (27 cases) in the upper layer of the epithelial tissue. No statistical difference in EGFR expression between each layer of cholesteatoma and postauricular skin was noted. However, there was an intensity gradient of positive EGFR immunoreactivity from the basal to the higher layers in cholesteatoma. Our results showed that the distribution of EGFR in middle ear cholesteatoma is not deranged, but is similar to that in normal skin tissue.

Adult↗
PubMed2003

Sinonasal NK/T-cell lymphoma with upper gastrointestinal bleeding: a case report.

Natural killer (NK)/T-cell lymphoma is the most common malignant lymphoma among sinonasal lymphomas. Diagnosis is difficult and prognosis is poor. Herein, we report the case of a 22-year-old male patient with sinonasal NK/T-cell lymphoma who first presented with nasal obstruction and left facial swelling. There was a mushroom-like mass over the hard palate, diffuse mucosal swelling in the left nasal cavity, and left orbital cellulitis. The patient underwent a Caldwell-Luc operation, functional endoscopic sinus surgery, and wide excision of the palate tumor. Pathologic examination of the maxillary sinus, nasal cavity, and palate tumor showed an NK/T-cell lymphoma. Two days after the operation, the patient suddenly had bloody stool and suffered hematemesis. A series of examinations revealed a small intestinal hemorrhage. Emergent exploratory laparotomy showed an ulcerative tumor mass with bleeding over the jejunum. Pathologic examination of the mass showed that it was the same as the sinonasal mass, an NK/T-cell lymphoma. We reviewed previous studies on nasal NK/T-cell lymphoma and found no report discussing patients with NK/T-cell lymphoma of both nasal and non-nasal origins. From this case, we learned that in patients with sinonasal NK/T-cell lymphoma, other sites may be involved.

Adult↗
PubMed2002

Space infection of the head and neck.

Deep neck infection may be lethal, especially when life-threatening complications occur. We conducted a retrospective analysis of 184 patients with deep neck infection who were treated at Kaohsiung Medical University Hospital during the past 6 years. Factors such as age, sex, hospitalization days, clinical presentations, involved spaces, imaging studies, microbiology, and treatment method were analyzed. There were 122 men and 62 women with a mean age of 41.7 years. The average hospitalization was 8.4 days. The involved spaces, determined by physical examination and radiologic findings, were the peritonsillar space (59 patients), parapharyngeal space (77 patients), submandibular space (55 patients), and retropharyngeal space (20 patients). Of the 49 patients for whom the origin of infection was identified, 29 were infected via the upper respiratory tract and 13 had infection of odontogenic origin. The most common isolated organism was Klebsiella pneumoniae. One hundred and thirty-seven patients (74.5%) underwent surgery, including repeated needle aspiration (87 patients) and surgical drainage (50 patients). The remaining 47 patients recovered uneventfully with antibiotic therapy alone. Eighteen patients developed life-threatening complications, such as descending mediastinitis, sepsis, airway obstruction, and jugular vein thrombosis. Two patients died of septic shock. The combination of accurate diagnosis, effective antibiotic therapy, airway maintenance, and intensive surgical debridement for those who fail to respond to conservative treatment will lead to a good prognosis.

Adolescent↗
PubMedDate not supplied

Correlation between proliferating cell nuclear antigen and p53 protein expression and 5-year survival rate in nasopharyngeal carcinoma.

PURPOSE: To assess the prognostic significance of p53 protein and proliferating cell nuclear antigen (PCNA) expression in nasopharyngeal carcinoma. MATERIALS AND METHODS: This study included 79 patients who had received treatment and regular follow-up for at least 5 years at a single institute. We used immunohistochemistry staining to assess p53 protein expression and PCNA labeling index (LI). Analyses were conducted on the association between each of the 2 biomarkers and pathological subtypes, TNM stage, the presence of locoregional recurrence, and 5-year survival rate. RESULTS: p53 protein nuclear staining was positive in 49 patients (62%). The mean PCNA LI was 55.6%, ranging from 3.35% to 92.9%. High PCNA LI (>55.6%) might contribute to higher 5-year survival rate, but it did not reach statistical significance (P = .09). Positive p53 protein staining and low PCNA LI were associated with the presence of locoregional recurrence. No statistical significance was found between p53 protein expression and PCNA LI and pathological subtypes and TNM stage. CONCLUSION: p53 protein and PCNA LI were not an ideal prognostic indicator in predicting 5-year survival rate in nasopharyngeal carcinoma. Future work will direct toward searching for other potential biomarkers with the hope to reinforce prediction of prognosis.

Adolescent↗