Background: Ectopic cervical thymomas are rare and there are few descriptions of the cytologic findings based on fine needle aspiration. Their appearances can be misinterpreted as either benign or malignant lesions of the thyroid. The authors report such a case occurring in a patient with Sotos syndrome, a genetic disorder characterized by somatic overgrowth and cognitive impairment. Case Report: The patient developed a neck mass that was examined first by fine needle aspiration and then by pathologic examination of the resected specimen. On fine needle aspiration, a diagnosis of papillary carcinoma of the thyroid was favoured, based on the presence of large cohesive sheets of anastomosing papillary tissue fragments with fibrovascular cores. Pathologic examination of the resection specimen showed a thymoma, subtype B3. The cytologic findings correlated with the presence of nuclear palisading of tumour cells around perivascular spaces. Conclusion: To the best of our knowledge, this histologic subtype of thymoma has never been reported in ectopic cervical thymic tissue, nor these particular cytologic findings that can lead to an erroneous diagnosis of thyroid carcinoma. Moreover, this is the first description of thymoma in association with Sotos syndrome.

1.
Oh YL, Ko YH, Ree HJ: Aspiration cytology of ectopic cervical thymoma mimicking a thyroid mass. A case report. Acta Cytol 1998;42:1167–1171.
2.
Choi H, Koh SH, Park MH, Kim SH: Myasthenia gravis associated with ectopic cervical thymoma. J Clin Neurosci 2008;15:1393–1395.
3.
Cohen JB, Troxell M, Kong CS, McDougall IR: Ectopic intrathyroidal thymoma: a case report and review. Thyroid 2003;13:305–308.
4.
Gerhard R, Kanashiro EH, Kliemann CM, Juliano AG, Chammas MC: Fine-needle aspiration biopsy of ectopic cervical spindle-cell thymoma: a case report. Diagn Cytopathol 2005;32:358–362.
5.
Jin XJ, Song JY, Choi SJ, Kim L, Park IS, Han JY, et al: Aspiration cytology of cervical thymoma – a case report. Korean J Pathol 2010;44:444–447.
6.
Martin JM, Randhawa G, Temple WJ: Cervical thymoma. Arch Pathol Lab Med 1986;110:354–357.
7.
Matsuura B, Tokunaga H, Miyake T, Utsunomiya S, Minami H, Onji M: A case of malignant thymoma mimicking thyroid carcinoma: a pitfall in fine-needle aspiration. Endocr J 2004;51:237–241.
8.
Milde P, Sidawy MK: Thymoma presenting as a palpable thyroid nodule: a pitfall in fine needle aspiration (FNA) of the neck. Cytopathology 1999;10:415–419.
9.
Ponder TB, Collins BT, Bee CS, Silverberg AB, Grosso LE, Dunphy CH: Diagnosis of cervical thymoma by fine needle aspiration biopsy with flow cytometry. A case report. Acta Cytol 2002;46:1129–1132.
10.
Vannucci J, Tassi V, Monacelli M, Puma F: Totally cervical thymoma from the orthotopic thymus. Thorac Cardiovasc Surg 2012;60:175–176.
11.
Vengrove MA, Schimmel M, Atkinson BF, Evans D, LiVolsi VA: Invasive cervical thymoma masquerading as a solitary thyroid nodule. Report of a case studied by fine needle aspiration. Acta Cytol 1991;35:431–433.
12.
Yan B, Lim D, Petersson F: Ectopic cervical thymoma: a report of two cases of a rare entity frequently misdiagnosed on fine needle aspiration cytology and frozen section. Head Neck Pathol 2010;4:152–156.
13.
Zeppa P, Varone V, Cozzolino I, Salvatore D, Vetrani A, Palombini L: Fine needle cytology and flow cytometry of ectopic cervical thymoma: a case report. Acta Cytol 2010;54(suppl 5):998–1002.
14.
Zakowski MF, Huang J, Bramlage MP: The role of fine needle aspiration cytology in the diagnosis and management of thymic neoplasia. J Thorac Oncol 2010;5(suppl 4):S281–S285.
15.
Muller-Hermelink HK, Mukai K, Sng I, Palestro G, Zettl A, Molina TJ, et al: Type B3 thymoma; in Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (eds): World Health Organization Classification of Tumours. Pathology and Genetics of the Lung, Pleura, Thymus and Heart Tumours. Lyon, IRAC Press, 2004, pp 164–166.
16.
Marx A, Strobel P, Zettl A, Chan JKC, Muller-Hermelink HK, Harris NL, et al: Thymomas; in Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (eds): World Health Organization Classification of Tumours. Pathology and Genetics of the Lung, Pleura, Thymus and Heart Tumours. Lyon, IRAC Press, 2004, pp 152–153.
17.
Strobel P, Marx A, Zettl A, Muller-Hermelink HK: Thymoma and thymic carcinoma: an update of the WHO Classification 2004. Surg Today 2005;35:805–811.
18.
Ryu HS, Koh JS, Park S, Kim MS, Cho SY, Lee SS: Classification of thymoma by fine needle aspiration biopsy according to WHO classification: a cytological algorithm for stepwise analysis in the classification of thymoma. Acta Cytol 2012;56:487–494.
19.
Wakely PE Jr: Cytopathology of thymic epithelial neoplasms. Semin Diagn Pathol 2005;22:213–222.
20.
Muller-Hermelink HK, Sng I, Palestro G, Molina TJ, Laeng RH, Harris NL, et al: Type B2 thymoma; in Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (eds): World Health Organization Classification of Tumours. Pathology and Genetics of the Lung, Pleura, Thymus and Heart Tumours. Lyon, IRAC Press, 2004, pp 161–163.
21.
Fukayama M, Hishima T, Fujii T, Zettl A, Shimosato Y: Squamous cell carcinoma; in Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (eds): World Health Organization Classification of Tumours. Pathology and Genetics of the Lung, Pleura, Thymus and Heart Tumours. Lyon, IRAC Press, 2004, pp 172–174.
22.
Wick MR, Zettl A, Baur AS, Muller-Hermelink HK, Marx A: Basaloid carcinoma; in Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (eds): World Health Organization Classification of Tumours. Pathology and Genetics of the Lung, Pleura, Thymus and Heart Tumours. Lyon, IRAC Press, 2004, p 175.
23.
Alexiev BA, Drachenberg CB, Burke AP: Thymomas: a cytological and immunohistochemical study, with emphasis on lymphoid and neuroendocrine markers. Diagn Pathol 2007;2:13.
24.
Fischer S, Asa SL: Application of immunohistochemistry to thyroid neoplasms. Arch Pathol Lab Med 2008;132:359–372.
25.
Xing M: BRAF mutation in thyroid cancer. Endocr Relat Cancer 2005;12:245–262.
26.
Cohen Y, Rosenbaum E, Clark DP, Zeiger MA, Umbricht CB, Tufano RP, et al: Mutational analysis of BRAF in fine needle aspiration biopsies of the thyroid: a potential application for the preoperative assessment of thyroid nodules. Clin Cancer Res 2004;10:2761–2765.
27.
Wu TH, Jin JS, Huang TW, Chang H, Lee SC: Ectopic cervical thymoma in a patient with myasthenia gravis. J Cardiothorac Surg 2011;6:89.
28.
Tatton-Brown K, Rahman N: Sotos syndrome. Eur J Hum Genet 2007;15:264–271.
29.
Berdasco M, Ropero S, Setien F, Fraga MF, Lapunzina P, Losson R, et al: Epigenetic inactivation of the Sotos overgrowth syndrome gene histone methyltransferase NSD1 in human neuroblastoma and glioma. Proc Natl Acad Sci USA 2009;106:21830–21835.
30.
Faravelli F: NSD1 mutations in Sotos syndrome. Am J Med Genet C Semin Med Genet 2005;137C:24–31.
31.
Schneider R, Bannister AJ, Kouzarides T: Unsafe SETs: histone lysine methyltransferases and cancer. Trends Biochem Sci 2002;27:396–402.
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