Tuberc Respir Dis.  2007 Apr;62(4):331-335. 10.4046/trd.2007.62.4.331.

A Case of Ectopic Cystic Thymoma

• Lee JH
• Kim IO
• Lee HK
• Min KW
• Kim SH
• Kim TH
• Sohn JW
• Yoon HJ
• Shin DH
• Park CK
• Kang JH
• Park SS

• KMID: 1970235
• DOI: http://doi.org/10.4046/trd.2007.62.4.331

Abstract

A thymoma commonly occurs in the superior mediastinum or the upper part of the anterior mediastinum but can be located in other places in rare cases. Cystic degeneration in a thymoma is a relatively common but focal event. In rare cases, the process proceeds to the extent that most if not all of the lesion becomes cystic. We report a case of a patient with a paracardial cystic thymoma in the lower aspect of the anterior mediastinum. A 49-year-old woman was referred to our hospital because of a mass discovered incidentally on a chest X-ray. She showed no symptoms or signs. Contrast-enhanced chest CT scan revealed a 5x5cm sized, well-marginated, right paracardial cystic mass with a curvilinear and oval enhancing solid portion. A Surgical resection was performed. The mass was discontinuous with normal thymic tissue. Microscopy revealed a type B1 thymoma with prominent foci of medullary differentiation according to the WHO classification. There was no capsular or local invasion. The postoperative course was uneventful and the patient was discharged in good health.

Keyword

Ectopic; Cystic; Thymoma

MeSH Terms

Classification
Female
Humans
Mediastinum
Microscopy
Middle Aged
Thorax
Thymoma*
Tomography, X-Ray Computed

Figure

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  Figure 1 Chest PA and lateral radiograph show a well-marginated right paracardial mass.

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  Figure 2 Contrast-enhanced chest CT scan shows a well-marginated right paracardial cystic mass with curvilinear and oval enhancing solid portion.

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  Figure 3 (A) Microscopy shows numerous lymphocytes with foci of medullary differentiation (H&E, ×40). (B) The neoplastic cells are predominantly lymphoid cells compared to few inconspicuous epithelial cells characterized by vesicular, clear nuclei and small nucleoli (arrow; H&E, ×40).

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