ERBB1- and ERBB2-Positive Medullary Thyroid Carcinoma: A Case Report

Area of Science:

• Endocrinology
• Oncology
• Molecular Biology

Background:

• Medullary thyroid carcinomas (MTCs) are rare neuroendocrine tumors originating from parafollicular C-cells.
• Their pathogenesis is linked to RET proto-oncogene alterations, with calcitonin as a key biomarker.
• Treatment typically involves total thyroidectomy, with advanced cases requiring tailored therapeutic strategies.

Observation:

• A case study of a 54-year-old female with an incidentally discovered 1 cm thyroid nodule.
• The nodule was classified as suspicious for MTC after a calcium stimulation test.
• Post-surgical analysis included immunohistochemistry, immunofluorescence, and electron microscopy.

Findings:

• The MTC nodule expressed intracellular calcitonin, consistent with its origin.
• Additionally, the tumor cells showed intracellular positivity for tyrosine kinase RTK receptors ERBB1 and ERBB2.
• Ultrastructural examination revealed heterogeneous spindle-shaped cells with two types of secretory granules.

Implications:

• The presence of ERBB1 and ERBB2 suggests their potential involvement in MTC proliferative responses.
• These oncoproteins might also play a role in the differentiation of parafollicular C-cells.
• Further research is warranted to elucidate the biological, prognostic, and therapeutic significance of ERBB1/ERBB2 expression in MTCs.