Unusual metastases from tall cell variant of papillary thyroid cancer

Background: TCV is considered more aggressive than classical variant of PTC. Distant metastases are more common among this variant and affect survival. Little is known about the molecular pattern of this histotype. Methods: We reported 2 cases of unusual metastases from TCV, BRAF V600E positive. Results: A 38-years-old-woman developed subcutaneous metastases during short term follow-up; at medium term follow-up, patient showed detectable stimulated serum Thyroglobulin without disease evidence at imaging. A 33 years-old-man, presented incidental thymic metastases at time of surgical treatment; this is the first case of not-ectopic thymic metastases from PTC. Conclusions: TCV may present with unusual metastases already during early follow-up. The more aggressive behavior could be linked to the higher prevalence of BRAF point mutations, but only a long-term follow-up might clarify if this association could worsen the prognosis. Moreover, skin metastases have been predictive factors of worse outcome in our patient, while not thymic metastates.