Conclusion:
In summary, we present an unusual case of PTC presenting as a cerebellar
metastasis, without an identifiable focus of PTC within the thyroid
gland, but rather an extrathyroidal deposit in a left level VI node. An
incidental focus of microMTC was present in the thyroidectomy specimen.
Management consisted of total thyroidectomy, resection and radiosurgery
of the cerebellar metastasis, and radioactive iodine ablation. There is
evidence of new skeletal lesions on follow-up FDG-PET scan suggestive of
RAI-refractory disease. This case highlights the rarity of distant
metastases in PTC and in particular brain metastasis, which confers
poorer prognosis. Such patients may exhibit genetic profiling that is
distinct from PTC without distant metastasis. Finally, the presence of
microMTC was an unexpected finding. The clinical relevance and risk
stratification of incidental microMTC in this setting requires further
studies