Spindle epithelial tumor with thymus-like differentiation (SETTLE): youngest reported patient.
Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a very rare thyroid tumor. It is one of a family of tumors arising either from ectopic thymus or remnants of branchial pouches that retain the potential to differentiate along the thymic line. Herein is reported a case of SETTLE in a 2-year-old girl. The patient underwent right thyroid lobectomy for a tumor of the right thyroid lobe. The resected specimen of this tumor revealed a whitish and solid mass. On microscopy, the tumor exhibited an area of spindle cells, glandular epithelium, and mucinous cystic lesions. The following findings were obtained on immunohistochemistry: the spindle cell area was diffusely positive for cytokeratin AE1/3 and vimentin, and partially positive for alpha-smooth muscle-specific actin. The glandular structures consisted of columnar cells and the cystic area was also positive for cytokeratin AE1/3. All three components of the tumor were negative for thyroglobulin, thyroid transcription factor-1, S-100 protein, carcinoembryonic antigen, somatostatin, synaptophysin, and chromogranin A. On the basis of the aforementioned findings, SETTLE was diagnosed. The patient remains disease free to date, 2 years after surgery with no additional treatment. To the best of the authors' knowledge the present SETTLE patient is the youngest yet reported.
Satoh
Shintaro
S
Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Saga University, Saga City, Nabeshima, Japan. satos3@cc.saga-u.ac.jp
Toda
Shuji
S
Narikawa
Keita
K
Watanabe
Keiko
K
Tsuda
Kuniyoshi
K
Kuratomi
Yuichiro
Y
Sugihara
Hajime
H
Inokuchi
Akira
A
D002277:Carcinoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D013950:Thymus Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery