Single lung and bone metastasis 30 years after thyroid cancer onset

Abstract

Background: Papillary thyroid carcinoma is the most common thyroid cancer. Lungs and bones are the most frequent sites of metastasis, characterized by a multiple nodular or miliary pattern. A solitary site of papillary thyroid cancer metastasis in lung and bone tissues is quite rare. Case report: We describe an unusual case of single bone and single pulmonary metastasis from papillary thyroid carcinoma. These metastases appeared 30 years after the onset of the primary tumour. In parallel, 15 years after the thyroid carcinoma, the patient also had breast cancer, which can typically cause both lung and bone metastases. Therefore there were many doubts about the diagnosis of these two lung and bone lesions: primitive or secondary tumours? and, if secondary, what was their primitive form? thyroid or breast? Immunohistochemical staining of both lung and bone lesions for different tumour markers was performed in order to determine the cancer histogenesis. Conclusions: In order to perform a differential diagnosis of metastasis and to choose an effective therapy, the oncologist must consider various parameters, such as thorough medical history evaluation and careful immunohistochemical analysis. A long-term relapse from papillary thyroid cancer should also be borne in mind.