The United States Environmental Protection Agency has classified fipronil as a possible human carcinogen based on an increase in thyroid follicular cell
tumors in rats.
Surgical resection of the metastasis with repair of the patellar tendon was performed, and pathology was also consistent with thyroid follicular cell
carcinoma (Figures 6 and 7).
The WHO definition of PDTC refers to the Turin proposal  which requires the tumour to be of follicular cell
derivation by conventional criteria and have a solid/trabecula/insular growth pattern, with absence of papillary thyroid carcinoma features and having features of either convoluted nuclei, 3 or more mitoses per 10 high power fields, or tumour necrosis [1, 2].
The lymphocytic infiltration of thyroid follicular cell
clusters was seen in 79 cases and Hurthle cells in 64 cases.
Detection of parathyroid hormone (PTH) and chromogranin are strongly associated with parathyroid cell origin, while detection of thyroglobulin is strongly associated with thyroid follicular cell
A modified five-level grading scale based on oedema, follicular cell
degradation, vascular congestion, haemorrhage and infiltration by inflammatory cells was used to determine the histopathological injury score of the ovary.
For morphological analyses, i.e., diameter of vitellogenic oocytes, the pellucid zone thickness and the follicular cell
height, we selected 50 undamaged oocytes without retraction and with cuts crossing the nucleus for each of the studied species.
Of the 462 nodules of follicular cell
composition that were submitted for molecular testing only 22 were ultimately diagnosed as malignant.
Ghossein, "Encapsulated thyroid carcinoma of follicular cell
origin," Endocrine Pathology, vol.
Yamashita, "Prognostic classification of thyroid follicular cell
tumors using Ki-67 labeling index: risk stratification of thyroid follicular cell
carcinomas," Endocrine Journal, vol.
Both of these hormones are involved in hormonal feedback pathways that regulate follicular cell
growth and differentiation.