TY - JOUR
T1 - Oncological Significance of WHO Histological Thymoma Classification
T2 - A Clinical Study Based on 286 Patients
AU - Okumura, Meinoshin
AU - Ohta, Mitsunori
AU - Miyoshi, Shinichiro
AU - Mori, Takashi
AU - Yasumitsu, Tsutomu
AU - Nakahara, Kazuya
AU - Iuchi, Keiji
AU - Tada, Hiroto
AU - Maeda, Hajime
AU - Matsuda, Hikaru
PY - 2002/5
Y1 - 2002/5
N2 - Objectives: The clinical significance of thymoma histology remains controversial because of the numerous histological classifications of thymic epithelial tumors. Universal classification of such tumors was achieved by the World Health Organization (WHO) in 1999. We studied the prognostic significance of this classification. Methods: We studied clinical features and postoperative survival in cases of thymoma, but not thymic carcinoma, based on WHO histological classification in 286 patients undergoing surgery between 1958 and 2001. Results: Tumors were 19 type A, 79 type AB, 59 type B1, 102 type B2, and 27 type B3. The proportion of invasive tumors increased by type - from A to AB, B1, B2, and B3. The great vessels were involved more frequently in type B2 and B3 tumors than in type A, AB, and B1 tumors. The 20-year survival was 100% in type A, 87% in type AB, 91% in type B1, 65% in type B2, and 38% in type B3 tumors. Multivariate analysis showed Masaoka staging and WHO histological classification to be significant independent prognostic factors, while age, gender, myasthenia gravis association, resection completeness and great vessel involvement were not. In stage III patients, 13 of 45 patients with type B2 and B3 tumor died of their tumors, while no tumor deaths occurred in 11 patients with type A, AB, and B1 tumors. Conclusion: WHO histological classification realistically reflects the oncological behavior of thymoma.
AB - Objectives: The clinical significance of thymoma histology remains controversial because of the numerous histological classifications of thymic epithelial tumors. Universal classification of such tumors was achieved by the World Health Organization (WHO) in 1999. We studied the prognostic significance of this classification. Methods: We studied clinical features and postoperative survival in cases of thymoma, but not thymic carcinoma, based on WHO histological classification in 286 patients undergoing surgery between 1958 and 2001. Results: Tumors were 19 type A, 79 type AB, 59 type B1, 102 type B2, and 27 type B3. The proportion of invasive tumors increased by type - from A to AB, B1, B2, and B3. The great vessels were involved more frequently in type B2 and B3 tumors than in type A, AB, and B1 tumors. The 20-year survival was 100% in type A, 87% in type AB, 91% in type B1, 65% in type B2, and 38% in type B3 tumors. Multivariate analysis showed Masaoka staging and WHO histological classification to be significant independent prognostic factors, while age, gender, myasthenia gravis association, resection completeness and great vessel involvement were not. In stage III patients, 13 of 45 patients with type B2 and B3 tumor died of their tumors, while no tumor deaths occurred in 11 patients with type A, AB, and B1 tumors. Conclusion: WHO histological classification realistically reflects the oncological behavior of thymoma.
KW - Masaoka staging
KW - Thymic epithelial tumor
KW - Thymoma
KW - WHO histological classification
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U2 - 10.1007/BF03032284
DO - 10.1007/BF03032284
M3 - Article
C2 - 12048910
AN - SCOPUS:0036580514
SN - 1344-4964
VL - 50
SP - 189
EP - 194
JO - Japanese Journal of Thoracic and Cardiovascular Surgery
JF - Japanese Journal of Thoracic and Cardiovascular Surgery
IS - 5
ER -