Journal List > J Korean Endocr Soc > v.23(4) > 1003448

Kim, Jeong, Kim, Lee, Kim, Yim, Kim, Kim, Kim, Gong, Shong, and Kim: A Case of Carcinoma Showing Thymus-Like Differentiation (CASTLE) in the Thyroid

Abstract

Carcinoma Showing Thymus-Like Differentiation (CASTLE) is a very rare malignant neoplasm of the thyroid, and this resembles lymphoepithelioma or squamous cell carcinoma of the thymus. It originates from ectopic thymic tissue or remnants of the branchial pouches. We recently experienced a case of CASTLE in the thyroid gland of a 61-year-old woman. She presented with an asymptomatic mass in the right thyroid gland and she was diagnosed with 'poorly differentiated carcinoma' of the thyroid by fine needle aspiration cytology (FNAC). Total thyroidectomy was performed for both diagnostic and therapeutic purposes. Histologic examination of the resected tumor showed that the tumor was lobulated with expanding fibrous bands, and it was infiltrated by lymphocytes and plasma cells. The tumor cells had oval, large vesicular nuclei and prominent nucleoli, and the immunohistochemical staining was positive for CD5 and bcl-2, so the patient was diagnosed with thyroid CASTLE. We report here on a case of CASTLE in the thyroid gland treated by surgery and external neck radiation therapy.

Figures and Tables

Fig. 1
Thyroid ultrasonography showed 3.3 × 3.1 × 4.7 cm-sized, well-defined hypoechoic solid mass in lower portion of right lobe of thyroid (A) and 0.4 × 0.4 × 0.4 cm nodule in left thyroid (B). No significantly enlarged lymph node was found in the neck.
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Fig. 2
The tumor was measured 4.7 × 3.5 × 3.2 cm and was well-defined and firm. The cut surface was creamy yellow to pale pink and granular with focal necrosis and hemorrhage.
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Fig. 3
(H&E, ×400) The interface of the tumor with the thyroid was smooth and relatively well-demarcated. Broad anastomosing islands of tumor cells were separated by lymphoplasmocyte-infiltrated desmoplastic stroma.
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Fig. 4
(H&E, ×400) The tumor cells had indistinct border and eosinophilic cytoplasm. The nuclei are oval and pale to vesicular with small distinct nucleoli. Small lymphocytes and plasma cell infiltrate in the tumor islands (lower field).
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Fig. 5
Immunostainigs for CD5 and Bcl-2 of the resected tumor showed tumor cells with strong positive staining.
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References

1. Miyauchi A, Kuma K, Matsuzuka F, Matsubayashi S, Kobayashi A, Tamai H, Katayama S. Intrathyroidal epithelial thymoma: an entity distinct from squamous cell carcinoma of the thyroid. World J Surg. 1985. 9:128–135.
2. Chan JK, Rosai J. Tumors of the neck showing thymic or related branchial pouch differentiation: a unifying concept. Hum Pathol. 1991. 22:349–367.
3. Dorfman DM, Shahsafaei A, Miyauchi A. Intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) exhibits CD5 immunoreactivity: new evidence for thymic differentiation. Histopathology. 1998. 32:104–109.
4. Roka S, Kornek G, Schuller J, Ortmann E, Feichtinger J, Armbruster C. Carcinoma showing thymic-like elements-a rare malignancy of the thyroid gland. Br J Surg. 2004. 91:142–145.
5. Kusada N, Hara Y, Kobayashi S, Weihua T, Nakamura Y, Kakudo K, Yuasa H. A case of aggressive carcinoma showing thymus-like differentiation with distant metastases. Thyroid. 2005. 15:1383–1388.
6. Reimann JD, Dorfman DM, Nose V. Carcinoma showing thymus-like differentiation of the thyroid (CASTLE): a comparative study: evidence of thymic differentiation and solid cell nest origin. Am J Surg Pathol. 2006. 30:994–1001.
7. Piacentini MG, Romano F, De Fina S, Sartori P, Leone EB, Rubino B, Uggeri F. Carcinoma of the neck showing thymic-like elements (CASTLE): report of a case and review of the literature. Int J Surg Pathol. 2006. 14:171–175.
8. Yoneda K, Matsui O, Kobayashi T, Gabata T, Minato H, Hirokawa M. CT and MRI findings of carcinoma showing thymus-like differentiation. Radiat Med. 2005. 23:451–455.
9. Chow SM, Chan JK, Tse LL, Tang DL, Ho CM, Law SC. Carcinoma showing thymus-like element (CASTLE) of thyroid: combined modality treatment in 3 patients with locally advanced disease. Eur J Surg Oncol. 2007. 33:83–85.
10. Gu MJ, Shim YR, Choi JH, Choi WH. Carcinoma showing thymus-like differentiation (CASTLE) of the thyroid gland. Korean J Pathol. 1999. 33:460–462.
11. Kim JP, Sung BG, Ahn SK, Lee SH. A case of carcinoma showing thymus-like differentiation. Korean J Otolaryngol. 2004. 47:470–473.
12. Ito Y, Miyauchi A, Nakamura Y, Miya A, Kobayashi K, Kakudo K. Clinicopathologic significance of intrathyroidal epithelial thymoma/carcinoma showing thymus-like differentiation: a collaborative study with Member Institutes of The Japanese Society of Thyroid Surgery. Am J Clin Pathol. 2007. 127:230–236.
13. Ahuja AT, Chan ES, Allen PW, Lau KY, King W, Metreweli C. Carcinoma showing thymic like differentiation (CASTLE tumor). Am J Neuroradiol. 1998. 19:1225–1228.
14. Kakudo K, Mori I, Tamaoki N, Watanabe K. Carcinoma of possible thymic origin presenting as a thyroid mass: a new subgroup of squamous cell carcinoma of the thyroid. J Surg Oncol. 1988. 38:187–192.
15. Damiani S, Filotico M, Eusebi V. Carcinoma of the thyroid showing thymoma-like features. Virchows Arch A Pathol Anat Histopathol. 1991. 418:463–466.
16. Hishima T, Fukayama M, Fujisawa M, Hayashi Y, Arai K, Funata N, Koike M. CD5 expression in thymic carcinoma. Am J Pathol. 1994. 145:268–275.
17. Dorfman DM, Shahsafaei A, Miyauchi A. Immunohistochemical staining for bcl-2 and mcl-1 in intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) and cervical thymic carcinoma. Mod Pathol. 1998. 11:989–994.
18. Da J, Shi H, Lu J. Thyroid squamous-cell carcinoma showing thymus-like element (CASTLE): a report of eight cases. Zhonghua Zhong Liu Za Zhi. 1999. 21:303–304.
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