POSTER SESSION I Monday, February 28, 2005   —  9:30 AM - 12:00 Noon Convention Center, Exhibit Hall B ENDOCRINE PATHOLOGY 56 Allelic Imbalance of Tumor Suppressor Gene Loci in Benign and Malignant Lesions of the Thyroid in Patients Who Had Radiation as Children (398) AM Assaad, JL Hunt - University of Pittsburgh, Pittsburgh, PA 57 Gene Expression Profile of PTC: Comparison of Follicular Variant and Classic Morphology PTC with Benign Follicular Patterned Lesions (408) SP Finn, PC Smyth, EM O'Regan, S Cahill, M Toner, C Timon, RJ Flavin, JJ O'Leary, OM Sheils - University of Dublin, Trinity College, Dublin, Ireland; Dublin, Ireland 58 Mutational Activation of BRAF Is Not a Major Event in Sporadic Childhood Papillary Thyroid Carcinoma (413) GA Hosler, E Rosenbaum, M Zahurak, Y Cohen, D Sidransky, WH Westra - The Johns Hopkins Medical Institutions, Baltimore, MD 59 Type IV Collagen Immunostaining Provides a Simple, Reliable Way To Distinguish between Adenoma and Normal Pituitary (416) JA Jarzembowski, RV Lloyd, PE McKeever - University of Michigan Hospitals and Clinics, Ann Arbor, MI; Mayo Clinic, Rochester, MN