PMC5346947_01
a The PET/CT image shows an increase in FDG uptake in the mediastinum (black arrow) and the cervical metastatic lymph node (white arrow). b The chest CT shows the mediastinal tumor infiltration of the large vessels and the trachea. c The histopathological finding shows anaplastic carcinoma. Hematoxylin and eosin staining. x60.
cro-0010-0175-g01.jpg
PMC5346947_01_cro-0010-0175-g01.jpg
f1
A generalized examination consisting of contrast-enhanced computed tomography (CT), FDG-positron emission tomography (PET), and endoscopy did not reveal a clear primary site in the head and neck region, and in addition to the mediastinal tumor, a right level IV cervical lymph node metastasis, pulmonary metastases, and bone metastases were observed (Fig. 1a). Biopsy results revealed papillary thyroid carcinoma and partially anaplastic transformation (Fig. 1c).
CT shows severe tracheal stenosis as a result of tumor invasion.
cro-0010-0175-g02.jpg
PMC5346947_01_cro-0010-0175-g02.jpg
f2
Therefore, we thought that suffocation would be unavoidable in the near future (Fig. 2).
a A rapid, prominent reduction of the mediastinal tumor led to the dead space in the mediastinum. The air within the mediastinal tumor represents the dead space caused by tumor necrosis after lenvatinib administration (arrow). b Abdominal CT shows progression of the liver metastases.
cro-0010-0175-g03.jpg
PMC5346947_01_cro-0010-0175-g03.jpg
f3
Necrosis of the mediastinal tumor developed, and a necrotic cavity formed without development of granulomas or scarring; as a result, a dead space developed in the anterior region of the trachea (Fig. 3a). In contrast, an increase in the size and number of bone and liver metastases was noted (Fig. 3b).