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. PATIENT: A 36-year-old woman was seen with a 6-year history of increasingly severe symptoms in the distribution of the left sciatic nerve. RESULTS: Electromyography indicated a sciatic nerve lesion in the region of the greater sciatic notch. Magnetic resonance imaging demonstrated a tumor involving the left sciatic nerve in this area. Light microscopy, electron microscopy, and immunohistochemistry results confirmed the presence of an atypical ganglion cell tumor of the sciatic nerve that exhibited prognostically conflicting clinical and histological features. CONCLUSIONS: To our knowledge, this is the first report of an atypical ganglion cell tumor affecting the sciatic nerve, and illustrates the value of detailed neurophysiological examination in localizing the site of peripheral nerve injury to facilitate focused neuroimaging when standard investigations are uninformative. Longer follow-up is required to determine the true biologic potential of this lesion.

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. METHODS: We reviewed 52 consecutive renal transplant biopsy specimens showing both acute tubulointerstitial and vascular rejection. Arteritis was graded for each H&E slide, and tubulitis was graded for each H&E and PAS/silver. The handling of renal allograft biopsy specimens in the U.K. was determined by means of a questionnaire. RESULTS: When two, as opposed to three, H&E slides were examined, arteritis was missed in 11.4% of cases; when only one H&E slide was examined, arteritis was missed in 33.3% of cases. When only one, as opposed to three, PAS/silver slide was examined, tubulitis was under-graded in 33.3% of cases. In the U.K., 40% of laboratories stain at least three slides with H&E, and 42% stain at least three slides with PAS/silver. Only 30% of laboratories conform to all the Banff guidelines for slide preparation. CONCLUSIONS: There is likely to be significant under-diagnosis and under-grading of acute rejection if the Banff '97 guidelines for slide preparation are not implemented. Most laboratories in the U.K. do not conform to these guidelines.