Three Cases of Anaplastic Thyroid Carcinoma Transformation and Leukocytosis during Lenvatinib Treatment

Since 2015, the cancer treatment lenvatinib has been used for patients with advanced radioactive iodine- (RAI-) refractory thyroid differentiated cancer; however, the drug’s long-term effects have not been fully investigated. We report three cases in which lenvatinib treatment initially improved the patients’ conditions, although they all died approximately 2 months after leukocytosis due to very aggressive disease progression with anaplastic thyroid carcinoma transformation. Serum interleukin-6 (IL-6) was elevated in all three cases, and granulocyte-colony stimulating factor (G-CSF) was elevated in two cases. The patients had a similar clinical course, with multiorgan metastasis and aggressive disease progression. Even with advanced cancer, lenvatinib has provided control of the disease. However, as long-term use of lenvatinib grows, it is possible that similar cases will increase, and we report our findings as an alert to other clinicians

Thyroid-Associated Ophthalmopathy after Radioactive Iodine Therapy for Metastatic Follicular Thyroid Carcinoma

Thyroid-associated ophthalmopathy (TAO) is an inflammation of the extraocular muscles and periorbital connective tissue caused by autoantibodies against common antigens to both the thyroid and orbit. The release of antigens and induction of hypothyroidism caused by radioactive iodine (RAI) therapy may exacerbate TAO. Here, we present the case of a 67-year-old-woman treated with RAI therapy for metastatic follicular thyroid carcinoma who presented with TAO during the course of sorafenib administration. Tg and TgAb levels were gradually decreased with sorafenib and lenvatinib treatment, and TAO was improved without any ophthalmologic treatment