Some surgeons have shown that tumors of the internal auditory canal and cerebellopontine angle may be removed with preservation of hearing through the suboccipital approach. If hearing is to be conserved, the cochlear division of the VIIIth cranial nerve and blood supply of the labyrinth must be preserved. In addition, surgical entry into the labyrinth, upon removal of the posterior wall of the internal auditory canal, must be avoided since it is likely to result in permanent sensorineural hearing loss. Careful anatomic dissection of 20 human temporal bones has shown that exposure of the lateral-most recess of the internal auditory canal from a suboccipital approach is impossible without injury to the endolymphatic duct, common crus, vestibule or ampulla of the posterior semicircular canal. Previous authors have suggested that exposure of the horizontal crest may be used as a safe landmark in avoiding labyrinthine injury. However, our study has shown that exposure of the horizontal crest usually leads to labyrinthine injury. In 19 out of 20 cases, the labyrinth would have been entered had the horizontal crest been used as a landmark for the lateral limit of bone removal. The application of the anatomical relationship quantified in this study may improve our ability to avoid labyrinthine injury in the suboccipital removal of acoustic neuromas.

Mycobacterial cervical lymphadenitis, or scrofula, may be caused by Mycobacterium tuberculosis, or the atypical mycobacteria. It is important to distinguish between tuberculous cervical lymphadenitis and atypical mycobacterial cervical lymphadenitis, since medical and surgical treatment of each of these entities is different. The two types of scrofula are compared and contrasted. The appropriate treatment of each is discussed, and the complications of improper management are described.

Superficial ulcerations of the oral mucosa often present a diagnostic challenge to the physician because of the similarity of one ulcer to another. A diagnosis is made by the analysis of multiple factors, including the lesion's location, size, grouping, onset, patient's age, involvement of other systems of the body, and course of the disease. The histopathology of the lesion may be specific, especially in certain potentially fatal diseases. This paper presents the means for the differential diagnosis of a variety of superficial ulcers of the oral mucosa: varicella, herpangina, recurrent aphthous stomatitis, Behcet's disease, Stevens-Johnson syndrome, traumatic ulcer, verrucous carcinoma, primary herpetic gingivostomatitis, recurrent herpetic stomatitis, pemphigus vulgaris, and benign mucous membrane pemphigoid.

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