Development of the parafollicular cells in recurrent goiter

Abstract

Objective: To provide more data for the discussion on whether thyroid hormones, iodide and other factors controlling the thyroid also influence the parafollicular (PF) cells, as the answer is of great importance for optimization of the medical treatment of medullary thyroid carcinoma (MTC) after surgery. Design: We compared the density of the PF cells in patients who underwent surgery for the second time due to recurrent goiter with that in normal-sized thyroid glands after the first operation. Methods: In 20 patients with only one operation, all specimens were taken from morphologically and functionally normal lobular thyroid parenchyma. The second group consisted of 30 patients who had already undergone a nearly total resection of at least one thyroid lobe several years before. Then another surgery of the same side was performed due to recurrent goiter. Immunohistochemical staining of the PF cells was performed using primary antibodies to calcitonin and chromogranin. Results: An average of 78 PF cells (median 12.5) was found in the sections with the highest density of the first group. The average number of PF cells in the second group was just 5 (median 0). The Wilcoxon test revealed a highly significant difference in the total PF cell content between the groups P , 0X001X Conclusions: Our study suggests that the stimulating factors that lead to growth of the thyroid parenchyma do not influence the PF cells. Hence a non-suppressive thyroid hormone replacement seems to be sufficient after resection of an MTC.

C-cells in colloid goiter

“…Studies of colloid goiters suggest that thyroid growth factors do not influence C-cells. This hypothesis is favored by the absence of C-cells in nodules of relapsing goiters, in which the tissue proliferation is predominantly asymmetric, differing from the homogeneous and regular hyperplasia of thyroid lobular parenchyma 26 .…”

Investigation of factors potentially influencing calcitonin levels in the screening and follow-up for medullary thyroid carcinoma: a cautionary note

“…Bones, the kidneys and the gastrointestinal tract are the main targets of the biolocigal effects of calcitonin. Evidence of interactions between C cells and thyroid cells suggest that there is a functional relationship between these types of cells although there is still a lack of precise data [9]. …”