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Schwannoma is a rare neoplasm in the E.N.T. areas although it is characteristic of this discipline. Indeed, examination of the most recent data in the literature shows that approximately 45% of all neoplasms of the peripheral nerve linings occur in the head and neck district, the most common neurogenic tumors are schwannomas and these constitute 35% of all head and neck tumors. In reviewing the literature attention was focused on schwannomas originating in unusual sites, neglecting the most common sites originating in the eighth and seventh pair of cranial nerves. It was seen that the site of origin and clinical manifestation of these lesions varies widely and the four cases presented here are no exception. These are four schwannomas which came under observation between 1994 and 1997. The sites of origin were, respectively: the floor of the mouth, the submandibular region (corresponding to the Warthon duct), the anterior wall of the external auditory canal and the hypopharynx (corresponding to the pyriform sinus). All of these cases proved quite rare in the literature. All the cases underwent accurate anatomopathological examination and the paper discusses the particular histological and immunohistochemical features encountered. Reference is also made to the problems of differential diagnosis vs. other types of soft tissue tumors. Emphasis is placed on the demonstrated difficulty in recognizing schwannomas from the macroscopic and surgical points of view. The absence of mitoses, necroses, invasiveness and specific features--i.e. hyperchromia and pleomorphism of the nuclei or the presence of large atypical cells--are all parameters confirming that the lesions observed in the present study were benign. No anatompathological features were observed that could justify any particular expression of the schwannoma in the specific sites involved. Nevertheless, the authors present these case because a review of the literature indicated that they are extremely rare and because differential diagnosis of these unusual manifestations is so complex.

A new method for the simultaneous assay of D- and L-enantiomers of carnitine is described. The method is based on precolumn derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate [(+)FLEC] producing a diastereomeric derivative which can be detected both by UV absorbance and fluorescence detection. Also acyl esters of carnitine can be processed with this method, after alkaline hydrolysis. The D-enantiomer of carnitine and acylcarnitine can be detected at a concentration as low as 0.2% in the raw material and in pharmaceuticals. Assays can be carried out using an autoinjector either by HPLC or capillary electrophoresis (CE) because the derivative proved to be very stable. Its application is proposed for the routine assay of the enantiomeric excess of L-carnitine and their acyl esters in pharmaceutical products.

Using the most recent TNM revision as a basic framework to build upon, the Authors set up a graphic representation of the larynx on the basis of data gathered using clinical-instrumental examination. This graph, which allows automatic extrapolation of the degree of T, represents various sites and subsites of the larynx (including the pre-epiglottic area, the retro-cricoid area and the piriform sinus) which are divided by different coloured lines. This simple graphic representation of cancerous tumours, whose various colours indicate tumor extension in depth (data had with CT and RM), allows for automatic T classification of larynx cancer on the basis of T extension as well as on that of the degree of vocal cord impairment. Particularly useful for students in memorizing TNM classification, this graph, furthermore, groves to be a means of facilitating under standing the disease as well as opinion exchange among members of the medical staff. As furthermore proves of utmost value in patient management in that it may be fed into computerized management programmes containing individual patient's records thereby permitting a more rapid classification of the tumor. Moreover, the data easily stored in the programme are readily accessible for eventual statistical elaboration. The Authors conclude with a proposal of the eventual use of a similar graph of other sites in the body which may be adapted in the event of future TNM revisions.

We studied middle ear pressure variations in 17 patients with mild upper airways or middle ear diseases, during nitrous oxide anaesthesia. We observed a significant increase in middle ear pressure during the administration of nitrous oxide, and a significant decrease after nitrous oxide was discontinued. Nine patients showed periodical reductions of the middle ear pressure during the inhalation of nitrous oxide, due to passive openings of the eustachian tube. In the remaining 8 patients (47%) this mechanism has not been effective. A comparison between these two groups shows significantly higher levels of middle ear pressure in the group of patients with abnormal function of the eustachian tube, both during and after the administration of nitrous oxide. Our results demonstrate that patients with mild upper airways or middle ear diseases are likely to show an impaired tubal function. Therefore, nitrous oxide should be used with caution in the presence of such diseases. Moreover, nitrous oxide is generally controindicated in middle ear surgery, as the pressure gradients between middle and external ear can jeopardize the success of the operation.

The allergic inflammation may contribute to the development of otitis media with effusion (OME). For this reason we have examined two groups of children: the first (group A) formed by 12 children with allergic rhinitis, the second (group B) by 15 children with hypertrophic adenoids. We have found respectively: pathologic otoscopy in 75% and 93% of cases; pathologic tympanometry in 83% and in 90%; pathologic audiometry in 60% and in 83%. This values are not significant according to a statistic analysis. Instead, the degree of compromission has been significant: in fact 16% of the children belonging to group A had a retracted and atelectatic eardrum in comparison with 33% of the children belonging to group B. Also tympanometry has confirmed this aspect: in fact 33% of group A showed type C and B tympanograms in comparison with 77% of group B. Besides, audiometry has confirmed the presence of hearing loss in the subjects with tympanometry of type C and B, belonging to both groups. For this reason the allergic rhinitis, because it may cause OME, must be treated in order to limit the negative effects of allergic nasal obstruction on the functionality of the middle ear.