Papillary thyroid carcinoma (PTC) is well known as a differentiated thyroid carcinoma with an established treatment protocol and high survival rates. Nevertheless, its tall cell variant (TCV) is more frequent diagnosed with larger tumor size, advanced age and metastasis comparing to other PTC cases, resembling an increased level of aggressiveness attributable to the histological subtype according to recent studies. We present the case of a 60-year-old woman who came for a recently increase of the thyroid and a left laterocervical mass associated with pain and alteration of general status. Thyroidectomy revealed a TCV of PTC with infiltration of the extrathyroid tissue. The laterocervical mass posed difficulties to surgical excision but in a second attempt proved to be an undifferentiated carcinoma. The findings were associated to a rapid deterioration of the patient's general condition finalized with death within less than three months from the initial presentation.