Calcitonin-negative medullary thyroid carcinoma in a young adult.
Philippos Tasioudis, Angeliki Emmanouilidou, Magdalini Louka et al.
✦ AI-curated · Sources linked
Case in brief
A young woman in her early 20s presented with a thyroid nodule and normal serum calcitonin levels, which typically indicate the absence of medullary thyroid carcinoma (MTC). Despite the lack of initial biochemical markers, further evaluation through cytology and immunohistochemistry led to a diagnosis of calcitonin-negative MTC. The case highlights the importance of comprehensive assessment in ambiguous thyroid nodules.
Diagnostic / clinical pearl
Clinicians should consider the possibility of medullary thyroid carcinoma even in the presence of normal calcitonin levels, necessitating thorough evaluation of thyroid nodules.
Why it matters
This case emphasizes the limitations of relying solely on standard tumor markers for diagnosing thyroid malignancies, advocating for a more nuanced approach in ambiguous cases.