Masaoka staging system

Links

 Protocol for the Examination of Specimens From Patients With Thymoma and Thymic Carcinoma (Link)

Pathologic Staging for Thymomas (Modified Masaoka Stage) (applies only to thymomas)

 Stage I: Grossly and microscopically encapsulated (includes microscopic invasion into, but not through, the capsule)
 Stage IIa: Microscopic transcapsular invasion
 Stage IIb: Macroscopic capsular invasion
 Stage III: Macroscopic invasion of neighboring organs
 Stage IVa: Pleural or pericardial dissemination
 Stage IVb: Hematogenous

References

1. Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC, eds. World Health Organization Classification of Tumours: Pathology and Genetics of Tumours of the Lung, Pleura, Thymus and Heart. Lyon, France: IARC Press; 2004.

2. Suster S, Moran CA. Problem areas and inconsistencies in the WHO classification of thymoma. Semin Diagn Pathol. 2005;22:188-197.

3. Suster S, Moran CA. Thymoma classification: current status and future trends. Am J Clin Pathol. 2006;125:542-554.

4. Moran CA, Suster S. Neuroendocrine carcinomas of the thymus (thymic carcinoid): clinicopathologic study of 80 cases with a proposal for histologic grading and clinical staging. Am J Clin Path. 2000;114:100-110.

5. Masaoka A, Monden Y, Nakahara K, Tanioka T. Follow-up study of thymomas with special reference to their clinical stages. Cancer. 1981;48:2485-2492.

6. Koga K, Matsuno Y, Noguchi M, et al. A review of 79 thymomas: modification of staging system and reappraisal of conventional division into invasive and non-invasive thymoma. Pathol Int. 1994;44:359-367.

7. Tsuchiya R, Koga K, Matsuno Y, et al. Thymic carcinoma: proposal for pathological TNM and staging. Pathol Int. 1994;44:505-512.

8. Yamakawa Y, Masaoka A, Hashimoto T, et al. A tentative tumor-node-metastasis classification of thymoma. Cancer. 1991;68:1984-1987.

9. International Union Against Cancer (UICC). TNM Supplement: A Commentary on Uniform Use. 3rd ed. New York: Wiley-Liss; 2003.

10. Tateyama H, Eimoto T, Tada T, et al. Immunoreactivity of a new CD5 antibody with normal epithelium and malignant tumors including thymic carcinoma. Am J Clin Pathol. 199;111:235-240.

11. Dorfman DM, Shahsafaei A, Chan JK. Thymic carcinomas, but not thymomas and carcinomas of other sites, show CD5 immunoreactivity. Am J Surg Pathol. 1997;21:936-940.

12. Alexiev BA, Drachenberg CB, Burke AP. Thymomas: a cytological and immunohistochemical study, with emphasis on lymphoid and neuroendocrine markers. Diagn Pathol. 2007;2:13.