[Distant metastases on acinic cell carcinoma of the parotid gland after 12 years symptom-free interval]. / Fernmetastasierung eines Azinuszellkarzinoms der Parotis nach 12-jährigem krankheitsfreien Intervall.

Acinic cell carcinoma of parotid gland as cause of distant metastases are rare. The patient was a 60-year-old woman who had in 1993 a acinic cell carcinoma of right parotid gland. Tumour can be resected through total parotidectomy with facial nerve anastomosis and modified radical neck dissection (T (3) N (2b) M (0)). Since the operation the patient has remained symptom-free without any sign of tumour recurrence. After 12 years the patient noted swelling in the region of sternum and biopsy was necessary. Histologically and immunohistochemically the diagnosis of distant metastase on acinic carcinoma of the parotid gland was confirmed.

[An optimal electrode position for recording auditory evoked brain stem potentials within the scope of pediatric audiology]. / Eine optimale Elektrodenposition für die Ableitung auditorisch evozierter Hirnstammpotentiale im Rahmen der Pädaudiologie.

BACKGROUND: Estimation of hearing threshold in children is based on reliable identification of a response to a stimulus in the near-threshold range. It is well known that only wave V can be detected in brainstem potentials evoked by near-threshold stimuli. So the question arises as to whether or not a noncephalic reference electrode compared to the common lateral postition of the reference electrode on the ipsilateral mastoid produces a more stable wave V of increased amplitude. METHOD: Thirty-three normal hearing children in three age groups (< 6 years, 6-10 years, > 10 years) were investigated. For a near-threshold stimulation with 100-microsecond-clicks (10, 20, 30 dB nHL), bioactivity was simultaneously recorded with the reference electrode in four different locations (ipsilateral mastoid, contralateral mastoid, ipsilateral earlobe, and noncephalic electrode). RESULTS: The noncephalic reference produced the highest absolute and scaled amplitudes. This finding was statistically significant. For all investigated intensities, recording with the noncephalic reference electrode yielded the highest number of reliable detectable potentials. Evaluation of the residual noise in the four recording locations revealed a significantly increased noise level for the noncephalic electrode at the nape of the neck. CONCLUSIONS: Even if the residual noise is increased, the use of noncephalic reference results in a more reliable detection of wave V compared to the conventional locations of the reference electrode.