C cell hyperplasia and carcinoma developing in sheep with experimentally-induced lymphosarcoma

Area of Science:

• Veterinary Pathology
• Endocrinology
• Oncology

Background:

• Thyroid C-cells produce calcitonin, regulating calcium levels.
• Lymphosarcoma is a cancer affecting lymphocytes.
• The relationship between lymphosarcoma and thyroid C-cell neoplasia is not well-established.

Purpose of the Study:

• To investigate the occurrence of thyroid C-cell abnormalities in sheep with experimentally-induced lymphosarcoma.
• To characterize the immunohistochemical and ultrastructural features of these C-cell changes.

Main Methods:

• Induction of lymphosarcoma in sheep.
• Gross and histopathological examination of thyroid glands.
• Immunohistochemical staining for calcitonin, calcitonin gene-related peptide, chromogranin A, and neurone-specific enolase.
• Ultrastructural analysis of C-cells.

Main Results:

• Two cases of bilateral C-cell hyperplasia and one case of C-cell carcinoma were identified in 11 sheep with lymphosarcoma.
• The sheep with C-cell carcinoma showed slightly elevated serum calcium levels.
• Hyperplastic and neoplastic C-cells were positive for calcitonin, calcitonin gene-related peptide, chromogranin A, and neurone-specific enolase.
• Secretory granules were abundant in neoplastic and hyperplastic C-cells ultrastructurally.

Conclusions:

• Experimentally-induced lymphosarcoma in sheep can be associated with thyroid C-cell hyperplasia and carcinoma.
• These C-cell neoplasms express markers typical of neuroendocrine differentiation.
• The findings warrant further investigation into the pathogenesis of C-cell changes in lymphosarcoma-affected sheep.