Cochlear Pathology in Experimental Otitis Media with Effusion ofGuinea Pig Caused by Endotoxin / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Injection of endotoxin into the middle ear of experimental animals results in otitis media with effusion and transient reversible hearing loss, which occurs in the higher concentration of endotoxin than the concentration found in human middle ear effusion. The purpose of this study was to investigate the histopathologic changes of the cochlea in guinea pigs with experimental otitis media with effusion induced by E.coli endotoxin. MATERIALS AND METHODS: Concentrations of lipopolysaccharides (LPS) from E.coli, such as 0.1 mg/ml, 1 mg/ml, and 10 mg/ml, were instillated into the middle ear cavity of 30 normal guinea pigs. Histopathologic changes of the cochlea were observed at 1 week after endotoxin instillation, using both light and electron microscope. Six normal guinea pigs were used as a control group whose middle ears were instillated with the physiologically sterile saline. RESULTS: There were deformation in the organ of Corti, partial loss of stereocilia in the hair cells, and vacuolation in stria vascularis at a concentration of 10 mg/ml lipopolysaccharides from E. coli. Mild morphologic abnormality of the cochlea was observed at the concentrations of 1 mg/ml and 0.1 mg/ml. CONCLUSION: A higher concentration of LPS in the middle ear cavity may produce severe inner ear damage, possibly resulting in the sensorineural hearing loss.

The Ten Cases of Recurrent Pleomorphic Adenoma of Parotid Gland / 대한이비인후과학회지

BACKGROUND: The main cause of recurrent pleomorphic adenoma of the parotid gland is known to be incomplete surgical excision or accidental rupture of tumor pseudocapsule during surgery, which results in spillage of tumor cells into the wound. Recurrent pleomorphic adenoma of the parotid gland warrants consideration since there is a potential for the risk of malignant conversion. OBJECTIVES: We investigated clinical characteristics of recurrent pleomorphic adenoma of the parotid gland and analyzed the results of the treatment to establish surgical management modalities. MATERIALS AND METHODS: We examined retrospectively 10 cases of recurrent pleomorphic adenoma of the parotid gland and reviewed their clinical features, histopathologic findings, operative findings and postoperative outcomes. Six cases were female and four were male with the mean age of 45.8 years at the time of treatment. The average follow up period was six years and three months. RESULTS: Primary treatments included mass enucleation in seven cases and superficial parotidectomy in three cases. We performed total parotidectomy via anterior approach for all cases and limited neck dissection on level II was performed for six cases in whom the tumor spread was suspected. No patient experienced permanent facial nerve paralysis and tumor recurrence postoperatively except for two patients who died of lung metastasis despite radical tumor extiration and radiotherapy. CONCLUSION: Recurrent pleomorphic adenoma of the parotid gland is largely dependent on primary treatment. Recurrent tumors usually have multiple lesions, therefore total parotidectomy with limited neck dissection should be combined as a treatment modality and always been in mind the possibility of malignant conversion.

Surgical Management of Substernal Goiter / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Substernal goiter, defined as any thyroid enlargement that has greater mass inferior to the thoracic inlet, is a relatively rare disease with a potential for malignancy and the risk of postoperative airway obstruction secondary to tracheomalacia. We investigated clinical characteristics of substernal goiters and analyzed the results of the treatment to establish modalities of the surgical management. MATERIALS AND METHODS: We examined, retrospectively, ten cases of substernal goiters and reviewed their clinical features, radiological findings, histopathologic findings, operative findings and postoperative complications. RESULTS: We found tracheal deviations in six patients, tracheomalacia in three patients and calcification in two patients. We performed partial thyroidectomy for 9 cases and total thyroidectomy and superior mediastinal dissection were done for a case which revealed to be follicular carcinoma. The main histopathologic findings were multinodular goiter in five cases, followed by follicular adenoma, and follicular carcinoma in one case. Endotracheal intubation was removed after 24 hours postoperatively for six cases who showed severe tracheal compression and tracheal deviation and the tracheopexy (tracheal suspension) to the sternum was performed for one case among them. CONCLUSION: Because of the possibilities of malignancy and the acute airway obstruction, the surgical treatment and careful postoperative airway management should be emphasized for substernal goiter.