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A rare case of ectopic papillary thyroid carcinoma transformed into squamous cell carcinoma
Author(s) -
Yasuoka Hironao,
Nakamura Yasushi,
Yoshida Kenichi,
Shimo Toshiro,
Tori Masayuki,
Matsui Yuuki,
Sakamaki Yasushi,
Tsujimoto Masahiko
Publication year - 2018
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/pin.12649
Subject(s) - pathology , thyroid , medicine , thyroid carcinoma , thyroglobulin , ectopic thyroid , metastasis , immunohistochemistry , lung , cancer
A rare case of a metastatic ectopic papillary thyroid carcinoma (PTC) of the lung that transformed into a squamous cell carcinoma (SCC) that resembles pulmonary SCC is reported. A subcutaneous ectopic PTC in the left anterior neck area, together with a normal thyroid gland, were excised. The ectopic PTC showed thyroglobulin, TTF‐1 and PAX‐8 immunoreactivity and a BRAF V600E mutation. During the post‐operative follow‐up period, a rapidly growing 2 cm nodular lesion in the lower left lobe of the lung was detected. The lung tumor consisted of solid sheets and nests of squamous cells but without the nuclear features of PTC. Neither papillary nor follicular structures of cancer cells were identified. Carcinoma cells were positive for TTF‐1, PAX‐8, p40, CK14, and p63, while showing a high Ki‐67 labeling index and a BRAF V600E mutation. These results support our interpretation of a PTC that originated from ectopic thyroid tissue in the left anterior neck and that developed a lung metastasis showing squamous cell differentiation.