TGF beta 1 immunostaining patterns and locations in adenoma which later recurred

To investigate whether the immunohistochemical pattern of TGF beta 1 may be a marker of relapse for adenomatous pathology, 18 follicular adenomas, surgically removed by hemithyroidectomy between 1977 and 1982, were studied. The adenomas were divided into two groups according to the presence (group 1, N = 9) or absence (group 2, N = 9) of nodules recurring in the residual thyroid tissue. The presence and location of TGF beta 1 were evaluated a posteriori by immunohistochemistry in the removed adenoma. Fifty randomly selected subcapsular follicles were studied in each adenoma in order to evaluate the percentage of positive follicles and TGF beta 1 intra-thyrocyte location. In adenoma of group 1, the percentage of positive follicles for TGF beta 1 was lower (80%) than in adenoma of group 2 (84%); this was, however, not statistically significant. The location of TGF beta 1 was mainly at the cell base of the epithelial cells in the microfollicles of group 1, but was dominant at the cell apex in group 2 (p < 0.01). In conclusion, adenoma recurrence is independent of TGF beta 1 production; it may be due to an abnormal TGF beta 1 regulation in response to hyperplasiogenic stimuli.