Elevated Procalcitonin Levels can Occur in Bacterial Infections and also in Medullary Thyroid Carcinoma.

Medullary thyroid carcinoma (MTC) is a rare and challenging type of thyroid cancer originating from parafollicular cells (C cells) that produce calcitonin. Diagnosing and monitoring this carcinoma can be complex due to its unique biomarkers. Procalcitonin (PCT), a precursor of calcitonin, and carcinoembryonic antigen (CEA) are important markers for MTC. Elevated PCT levels, particularly when they remain high post-infection treatment, and elevated CEA levels are significant indicators for suspecting MTC. This report emphasises the diagnostic and prognostic importance of these biomarkers in MTC, highlighting their roles in detecting and monitoring disease progression. Integrating PCT and CEA measurements into routine clinical practice can enhance detection, provide understanding of therapeutic responses and aid in the effective management of MTC.

Learning points: Procalcitonin (PCT) is a more stable and reliable biomarker than calcitonin for diagnosing and monitoring medullary thyroid carcinoma (MTC).Elevated carcinoembryonic antigen (CEA) levels effectively monitor MTC progression, especially when calcitonin levels are inconsistent.Incorporating PCT and CEA measurements into routine practice enhances MTC management, providing reliable biomarkers for diagnosis and monitoring.