[Re-evaluation of the diagnosis in congenital hypothyroidism]. / La rivalutazione della diagnosi nell'ipotiroidismo congenito.

Newborn screening for congenital hypothyroidism (CH) has become routine in Italy. It provided new information regarding the epidemiology, diagnosis and treatment of CH infants and allowed to identify transient disorders of thyroid function in infancy. In fact, when the permanence of hypothyroidism has not been established in the newborn period, a confirmation of the diagnosis at 2-3 years of life should be performed. In this study results regarding the diagnosis reevaluation performed in 23 out of 184 CH children followed at the follow-up center for CH of the University of Rome "La Sapienza", are reported. Eleven of 23 reevaluated children had transient hypothyroidism (TH) and permanent CH was confirmed in the others. Four of the 11 TH children had law gestational age at birth, 1 had high antithyroid peroxidase titre due to maternal autoimmune thyroiditis and 2 were resident in iodine deficient areas. Our results show the importance of diagnosis reevaluation to identify transient disorders of thyroid function in infancy and confirm the role of neonatal, maternal and environmental factors in the etiopathogenesis of TH.

[Hürthle cell tumors: personal experience]. / Tumori a cellule di Hürthle: esperienza personale.

Hürthle cell tumors of the thyroid gland are uncommon lesions (3% of all well differentiated tumors). Histological diagnosis is often difficult: according to recent criteria only those tumors with almost 75% of oxyphil cells are well recognized as Hürthle cell neoplasms. Extracapsular and blood-vessels invasion, capsular penetration, DNA patterns and tumoral necrosis are indicative for malignancy. The Authors report their experience in the management of 46 patients who underwent thyroid surgery for Hürthle cell neoplasms. Histological findings, surgical approach and post-operative follow up are discussed.

Cyclin D1 and Cyclin E expression in malignant thyroid cells and in human thyroid carcinomas.

Evidence of the involvement of cyclin gene alterations in human cancer is growing. In this study, we sought to determine the pattern of expression of cyclin D1 and cyclin E in normal and malignant thyroid cells. Quiescent rat thyroid cells in culture, induced to synthesize DNA by thyrotropin (TSH), expressed cyclin D1 gene after 6 hr and cyclin E gene with a peak at 18 hr from the stimulus; K-ras-transformed rat thyroid cells, which grew without addition of hormones necessary for normal cell proliferation, expressed elevated levels of cyclin D1 and cyclin E, compared with normal differentiated thyroid cells. Human benign and malignant thyroid tumors and their relative normal tissues were then analyzed. Neither major genetic alterations nor amplifications for cyclin D1 and cyclin E genes were found by Southern blot analysis in genomic DNAs extracted from all types of thyroid tumors. Moreover, statistical analyses of densitometric values from Northern blots did not show increased levels of cyclin D1 and E mRNAs in the tumor samples, compared with normal thyroid. Immunohistochemical analyses of formalin-fixed paraffin-embedded sections of tissues with specific antibodies revealed a prevalent cytoplasmic cyclin E staining in the thyroid tissues analyzed. Cyclin D1, instead, was present in the cytoplasm of normal thyroids and adenomas, but in 31% of thyroid papillary carcinomas analysed, it was overexpressed, with a localization in the nucleus. Our in vivo observations suggest that unlike cyclin E, elevated nuclear cyclin D1 expression defines a subset of thyroid papillary carcinomas, and might be a contributory factor to thyroid tumorigenesis.