title: Aspiration cytology of an ectopic cervical thymoma misinterpreted as a lymphoproliferative lesion of the thyroid: A case report.
abstract: Ectopic cervical thymoma is a rare tumor that originates from ectopic thymic tissue trapped during the migration of the embryonic thymus. To the best of our knowledge, only 14 cases of ectopic cervical thymoma, which include descriptions of the cytological features based on fine-needle aspiration (FNA), have been reported thus far. The current study describes the case of a 52-year-old male presenting with an enlarging anterior neck mass that been apparent for a number of years and was now accompanied by shortness of breath. FNA cytology revealed large numbers of small lymphocytes admixed with rare groups of large, polygonal cells that were interpreted to be reactive lymphocytes or possible follicular dendritic cells. However, no definite follicular or Hürthle cells were identified. Therefore, the overall cytological features were misinterpreted as a lymphoproliferative lesion. However, subsequent histological analysis of the resected left total lobectomy specimen determined a diagnosis of thymoma, type B1. Thus, awareness of this entity combined with a careful search for thymic epithelial cells may aid in determining a correct diagnosis when FNA is performed for the evaluation of a neck mass.
authors.affiliation: Department of Pathology, Chi-Mei Medical Center, Tainan 71004, Taiwan, R.O.C.
authors.forename: Yi-Ying
authors.initials: YY
authors.lastname: Lee
authors.affiliation: Department of General Surgery, Chi-Mei Medical Center, Tainan 71004, Taiwan, R.O.C.
authors.forename: Wen-Ching
authors.initials: WC
authors.lastname: Wang
authors.affiliation: Department of Pathology, Chi-Mei Medical Center, Tainan 71004, Taiwan, R.O.C. ; National Institute of Cancer Research, National Health Research Institutes, Tainan 71005, Taiwan, R.O.C. ; Kaohsiung Medical University, Kaohsiung 80708, Taiwan, R.O.C. ; Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 71005, Taiwan, R.O.C.
authors.forename: Chien-Feng
authors.initials: CF
authors.lastname: Li
keywords: ectopic cervical thymoma; fine-needle aspiration; neck