ObjectiveTo investigate the succession model for hyperthyroidism and thyroid carcinoma secondary to nodular goiter in iodine deficiency area. MethodsA total of 216 specimens of goiter patients from iodine deficiency area were collected in the former 3rd hospital of Norman Bethune Medical College from January 1980 to December 1994. Twentyfour heteroploid samples were selected by the method of Hedley with Flow cytometry (FCM) analysis. Paraffin-embedded tissues from the same position were used to perform immunohistochemical staining for proliferating cell nuclear antigen (PCNA), laminin (LN), factor Ⅷ related antigen (FⅧ-RAg), and p53. The proliferative activity, stroma change, and angiogenesis were observed. ResultsPCNA label index (PCNA-LI) and proliferation index (PI) consistent in 24 heteroploid samples with PCNA staining were significantly higher value. PCNA positive cells were mainly distributed over nonfollicular parenchymatous structures, small follicles, and multilayered structures with large bubbly follicles. Destroyed basement membrane and necrosis were found by LN staining in PCNA positive position with vigorous reproductive capacity. Combining FⅧ-RAg staining with LN staining, interstitial proliferation and angiogenesis were obvious in follicular epithelial cells with vigorous reproductive capacity, providing nutrition and superior environment for them. ConclusionsThe reproduction of thyroid follicular epithelial cells, interstitial proliferation, and angiogenesis are all involved in tuberosis and hyperthyroidism, forming precancerous lesion, which suggest the succession model of goiter in iodine deficiency area.