The absence of Harvey ras mutations during development and progression of squamous cell carcinomas of the head and neck.

We have examined the incidence of Harvey ras mutations in human squamous cell carcinomas (SCC) of the upper aerodigestive tract using the polymerase chain reaction (PCR) followed by direct sequencing. No mutations were detected at codons 12, 13, 59 or 61 of this gene in any of six papillomas, five erythroplakias, 56 squamous cell carcinomas, and 16 SCC cell lines. Some of the SCC were lymph node metastases (three) or tumours which had recurred following radiotherapy (seven). We conclude that Harvey ras mutations are not a common event in the pathogenesis or recurrence of SCCs from Caucasian subjects, in contrast to the situation with Indian populations (Saranath et al., 1991).

Paediatric tracheostomy. Fifty-seven operations on fifty-three children.

Fifty-seven operations on 53 patients represents the total experience of tracheostomy in children under 13 years during 1964-1985 in an area with half a million inhabitants. No complication occurred during surgery and no deaths were related to the operations. Complications followed 16 out of 30 (53%) operations on children under three years and four out of 27 (15%) of the remainder, an overall complication rate of 35%. Many fewer operations have been required since 1973 because of the successful employment of nasotracheal intubation in the treatment of upper and lower airway obstruction caused by acute infection. Obstruction by-pass remains the commonest function of tracheostomy, with congenital lesions and trauma now the commonest causes of obstruction as opposed to acute infection in the earlier years. Despite the successful use of nasotracheal intubation there were absolute indications for tracheostomy--blockage of the nasotracheal tube; inability to intubate a child with epiglottitis; and necessity for an artificial airway of long duration.

Maxillary sinus hypoplasia and superior orbital fissure asymmetry.

Misdiagnosis of maxillary sinus hypophasia usually as sinus infection, sometimes as neoplasm, can lead to unnecessary and difficult surgical explorations. Associated anatomical abnormalities, e.g., caudal displacement of the ipsilateral frontal lobe of the brain or central position in the maxilla of the infraorbital nerve may create unexpected surgical hazards. Associated orbital enlargement can lead to diagnostic confusion in the investigation of headache, especially if the superior orbital fissures show marked asymmetry suggesting erosion. Projection of the fissure into the antrum in Waters view can simulate trabeculation of the sinus or fracture of the inferior orbital rim. Radiologic examination of 500 patients without intracranial or intraorbital lesions revealed maxillary sinus hypoplasia in 36 cases (7.2%) and in half the hypoplasia was unilateral (sinus asymmetry); aplasia was not encountered. Fissure asymmetry was present in 30 cases (6%), being present in 3.66% of patients with normally developed sinuses and in 36.1% of the hypoplasia patients. The appearances and measurements of the fissure are presented and examples of marked normal fissure asymmetry are demonstrated. Maxillary sinus hypoplasia is classified in this series as grade I-mild hypoplasia with limited inferolateral expansion (4 cases) and grade II in which there is also a curved orbital floor and lateral displacement of the adjacent nasal wall (32 cases).

Poststapedectomy otitis media and meningitis.

A patient developed acute otitis media, labyrinthitis, and meningitis 16 months after a stapedectomy operation, and 14 similar cases have been collected from the literature. Poststapedectomy otitis media carries an increased risk of labyrinthitis and meningitis and requires prompt antibiotic therapy and regular observation until cured. Should labyrinthitis occur, with or without meningitis, fistula repair must be undertaken as soon as the infection is eliminated. All stapedectomy patients require regular supervision, and must report for urgent treatment if symptoms of otitis media or perilymph fistula occur. Stapedectomy techniques should not employ sharp bevelled prostheses, and autogenous tissue grafts are probably superior to an absorbable gelatin sponge in protecting the inner ear. Eustachian tube problems and recurring or chronic upper-respiratory tract infections can predispose to middle ear infection and are thus contraindications to stapedectomy.