ABSTRACT
Diagnostic challenges can be encountered in combinations of two or more histological patterns, in poorly differentiated tumors, and in some Hurthle tumors as well as when distinctions are to be made between benign and malignant follicular thyroid nodules. Aneuploidy in medullary thyroid carcinoma (MTC) is correlated with an aggressive growth pattern. A characteristic instability of the centromeric region of chromosome 16 and somatic pairing of the homologous chromosomes 16 have also been observed in MTC. Chromosome 10 appears also to be involved in nonpapillary thyroid cancers in association with other chromosome aberrations. Differentiation between benign and malignant neoplasia of the parathyroid gland may present a diagnostic dilemma, and a combination of morphological and clinical features, including the presence or absence of metastases, is needed to recognize a malignancy. The linkage information obtained using polymorphic deoxyribonucleic acid probe RBP3 for the chromosome 10q1 pericentric region was adequate to provide genetic counseling for multiple endocrine neoplasia IIA to 63% of families.
