Atypical ganglion cell tumor of the sciatic nerve.

Context: Although herniation of a lumbosacral intervertebral disk is a major cause of sciatic distribution pain, relentlessly progressive symptoms or signs should alert one to the possibility of a tumor involving the nerve.

Objective: To describe the clinical, neurophysiological, and histological features of a pathologically unique tumor involving the sciatic nerve.

Setting: Tertiary referral university hospital.

Diagnosis of acute renal allograft rejection: evaluation of the Banff 97 Guidelines for Slide Preparation.

Background: Arteritis and tubulitis, the diagnostic features of acute renal allograft rejection, are typically focal lesions. To avoid under-diagnosis, the Banff '97 schema recommends the preparation of multiple slides, of which three should be stained with hematoxylin and eosin (H&E) and three with periodic acid-Schiff (PAS) or silver. In this study, we examine the validity of the Banff '97 recommendations and determine how widely these recommendations are applied.