Development of ganglion cell topography in the postnatal cochlea.

In mammals, the size and number of spiral ganglion cells can vary significantly along the length of the cochlea. At present, it is unclear how these topologic differences in spiral ganglion cell morphology and density emerge during development. We addressed this issue by quantifying developmental changes in the number, density, and size of auditory ganglion cells within the cochlea of Mongolian gerbils throughout the first 3 weeks of postnatal life. In each cochlea, cells were measured at five standardized locations along the length of the spiral ganglion, as determined from serial reconstruction of Rosenthal's canal. During the first postnatal week, the total number of gerbil spiral ganglion cells decreased significantly by 27%, without further change thereafter. This brief period of neuronal cell death coincides with a major remodeling in the afferent neural projections to gerbil auditory hair cells (Echteler [1992] Proc. Natl. Acad. Sci. USA 89:6324-6327). The resulting reduction in neuronal density varied with location, being most prominent within the upper basal and lower middle turns of the cochlea. These same regions contained the smallest auditory ganglion cells found within the gerbil ear and exhibited the least amount of developmental expansion in the circumference of Rosenthal's canal. These results suggest the possibility that regional differences in auditory neuron size and number might be influenced by local extrinsic factors, such as the availability of canal space.

Head and neck manifestations of plasma cell neoplasms.

Multiple myeloma, solitary plasmacytoma of bone, and extramedullary plasmacytoma are plasma cell neoplasms. They represent distinct manifestations of a disease continuum, whereby the clinical findings are critical to diagnosis. Plasma cell neoplasms are histologically similar, and distinguishing one from the other has significant implications for treatment and survival. Plasma cell neoplasms are relatively unusual malignancies of the head and neck region. We present a case series of plasma cell neoplasms involving the skull base, paranasal sinus, larynx, and mandible as an introduction to a complete review of the literature on plasma cell neoplasms of the head and neck area.

Periauricular cysts and sinuses.

Periauricular cysts, sinuses, and fistulas occur commonly in the pediatric population. They arise from developmental defects of the first branchial cleft and first branchial arch. In most instances the diagnosis and management of these conditions are straightforward, but exceptional presentations sometimes occur. Failure to recognize these unusual cases may result in inadequate treatment and subsequent recurrence, and even if the correct diagnosis is made, surgical management of these lesions may be complicated. A series of 15 cases of periauricular congenital lesions is reviewed, of which three cases illustrating a diagnostic or surgical challenge are presented. The embryology, presentation, and management of these anomalies are discussed. This is one of the largest series of first branchial cleft anomalies reported in the literature, and our paper uniquely discusses first branchial cleft anomalies and preauricular sinuses together, with an emphasis on the surgical management of facial nerve, external ear, and middle ear involvement.

Apoptosis and p53 in inverting papilloma of the sinonasal tract.

The objective of this study was to identify apoptotic bodies and p53 positivity in inverting papilloma lesions to study these two as biomarkers in premalignant lesions. Archival specimens of 15 patients with inverting papilloma between the years 1992 and 1995 were retrieved. In situ end labeling technique was used to identify apoptotic bodies. Immunohistochemistry was used to detect p53 in the same specimens. The clinical course was evaluated conducting a retrospective chart review in these patients. Compared to normal epithelium, inverting papilloma lesions had a greater proportion of apoptotic bodies, which was nearly statistically significant (average 0.506/100 cells for inverting papilloma compared with 0.1/100 cells for the normal surrounding tissue). Four cases of inverting papilloma were p53 positive. There was, however, no association between p53 positive staining and the apoptotic rate. The minimum follow-up for patients was 2 years. All had a uniformly good clinical outcome with only one patient who was p53 positive showing concurrent squamous cell carcinoma. We concluded that inverting papilloma contained a higher average number of apoptotic bodies compared with normal surrounding sinonasal tissue. This showed a trend toward a positive between the apoptotic rate and premalignancy, suggesting both increased cellular proliferation and increased cell death may occur in such lesions. In this study p53 did not show a positive association with the apoptotic rate, suggesting that p53 may not be directly involved in the apoptotic regulatory pathway in inverting papillomas.