The operating microscope in the management of melanotic neuroectodermal tumor of infancy.

Melanotic neuroectodermal tumor of infancy is a rare condition that is most commonly found within the head and neck regions. We present a 4-month-old boy with a melanotic neuroectodermal tumor of infancy of his maxilla. Because of the fairly high recurrence rate, the operating microscope was used after surgical excision to remove unseen remnants of the pigmented lesion. The patient has been followed for 4 years without signs of recurrence.

Chondrocyte volume fraction distribution in porcine septal cartilage: an initial stereoscopic evaluation.

This study uses stereology to determine the volume fraction distribution of chondrocytes throughout septal cartilage. En bloc submucous resection of septal cartilage from four different age groups was performed. Each age group contained three pigs. The weight, volume, and dimensions of the septi were determined. The septi were fixed, embedded in plastic, sectioned vertically at regular intervals along their anterior-posterior axis, and stained with toluidine blue. Each section was further stratified horizontally to allow chondrocyte volume fraction changes to be observed as a function of the two-dimensional location within the septum. The volume fraction of the chondrocytes within the septal cartilage was obtained through light microscopy and stereologic technique. Nested analysis of variance for age groups, individuals within age groups, and locations on the septum was performed. Additionally, unequal number-comparison tests for age groups were calculated. Gross septal parameter changes regarding weight, volume, and length all increased with advancing age. Overall, chondrocyte volume fraction decreased with advancing age. Chondrocyte volume fraction was not found to vary along the anterior-posterior axis or along the vertical axis. Stereologic methodology is an unbiased, simple, and efficient technique to understand the distribution of cells within a tissue.