ECE2007 Poster Presentations (1) (659 abstracts)
A 34 year-old female patient was admitted to the hospital because of a large nodule in the left thyroid lobe and elevated calcitonine level. A large encapsulated tumor was found and total thyroidectomy with left neck dissection was performed. Pathohistology revealed medullary and papillary carcinoma separate from each other in tumor tissue but mixed in regional lymph nodes. Papillary component was dominant in thyroid tissue but not in lymph nodes. Both calcitonine and thyroglobulin plasma levels were elevated after the surgery witch suggested distant metastases. I131 scintigrafy showed focal accumulation in the left side of the neck, thoracal vertebrae and diffuse accumulation in the ribs. DMSA and I131MIBG scintigraphy revealed pathologic focuses in the left thyroid lobe region. None of these focuses was confirmed by MRI. The octreoscan was negative. Genetic analysis of RET protooncogene was negative. The patient was treated with radiotherapy.
Conclusion: Synchronous occurrence of medullary and papillary carcinoma of the thyroid gland is very rare and a few cases were described in the literature. Concurrency of two distinct cell lines may suggest that they have a common stem cell origin or possible activation of a common tumorigenic pathway. However, synchronous coincidental genetic event cannot be excluded.