Limits...
Thymic epithelial tumors classified according to a newly established WHO scheme: CT and MR findings.

Han J, Lee KS, Yi CA, Kim TS, Shim YM, Kim J, Kim K, Kwon OJ - Korean J Radiol (2003 Jan-Mar)

Bottom Line: Thymic epithelial tumor is a distinctive pathologic entity exhibiting variable histologic features and heterogeneous oncologic behavior.Among the various classification systems, that of the World Health Organization has been adopted because of good correlation between histologic appearance and oncologic behavior.However, imaging findings among the various types overlap to some extent, and the ability of imaging studies to differentiate types AB, B1, B2, and B3 is limited.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

ABSTRACT
Thymic epithelial tumor is a distinctive pathologic entity exhibiting variable histologic features and heterogeneous oncologic behavior. Among the various classification systems, that of the World Health Organization has been adopted because of good correlation between histologic appearance and oncologic behavior. Radiologically, a smooth contour and round shape are most suggestive of a type-A tumor, whereas an irregular contour most strongly suggests type C. Pleural seeding is rare in type-A and AB tumors; calcification is suggestive of type B. Type-C tumors are significantly larger and more commonly associated with lymphadenopathy than type B3. At T2-weighted MR imaging, lobular internal architecture is more prominent in types B1, B2, and B3 tumors than in others. However, imaging findings among the various types overlap to some extent, and the ability of imaging studies to differentiate types AB, B1, B2, and B3 is limited.

Show MeSH

Related in: MedlinePlus

Type-B2 thymoma in a 35-year-old woman.A. Enhanced 10-mm-collimation CT scan obtained at the level of the right interlobar pulmonary artery shows that in the anterior mediastinum, a slightly attenuated heterogeneous mass is present.B. CT scan (10-mm collimation) obtained at the level of the suprahepatic inferior vena cava depicts a pleural mass lesion (arrows) with low attenuation.C. T1-weighted MR image obtained at a similar level to A shows a mass lesion with high-signal intensity.D. T2-weighted image depicts a slightly heterogeneous high-signal lesion.E. Photomicrograph (original magnification, × 1; hematoxylin-eosin staining) shows an invasive tumor bud (arrowheads) penetrating the capsule where there is no fibrous sleeve.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2698058&req=5

Figure 5: Type-B2 thymoma in a 35-year-old woman.A. Enhanced 10-mm-collimation CT scan obtained at the level of the right interlobar pulmonary artery shows that in the anterior mediastinum, a slightly attenuated heterogeneous mass is present.B. CT scan (10-mm collimation) obtained at the level of the suprahepatic inferior vena cava depicts a pleural mass lesion (arrows) with low attenuation.C. T1-weighted MR image obtained at a similar level to A shows a mass lesion with high-signal intensity.D. T2-weighted image depicts a slightly heterogeneous high-signal lesion.E. Photomicrograph (original magnification, × 1; hematoxylin-eosin staining) shows an invasive tumor bud (arrowheads) penetrating the capsule where there is no fibrous sleeve.

Mentions: According to Tomiyama et al. (4), smooth contours and a round shape most strongly suggest a type-A tumor (Table 2) (Fig. 2); type-C tumors are significantly larger than types A and B2 (Figs. 2, 5, 7, 8); irregular contours and mediastinal lymphadenopathy are most suggestive of type C (Figs. 7, 8). Calcification is more frequently seen in type-B1, B2, and B3 tumors than in type AB and type C (Fig. 6). A high degree of homogeneous enhancement tends to indicate type A or AB (Fig. 2); heterogeneous enhancement is seen more often in types B3 and C (Fig. 8). Mediastinal lymphadenopathy is present in 43% of type C tumors, 7% of type AB, but not in other types of thymic epithelial tumors. This feature has, however, been found to be of limited value in differentiating types AB, B1, B2, and B3.


Thymic epithelial tumors classified according to a newly established WHO scheme: CT and MR findings.

Han J, Lee KS, Yi CA, Kim TS, Shim YM, Kim J, Kim K, Kwon OJ - Korean J Radiol (2003 Jan-Mar)

Type-B2 thymoma in a 35-year-old woman.A. Enhanced 10-mm-collimation CT scan obtained at the level of the right interlobar pulmonary artery shows that in the anterior mediastinum, a slightly attenuated heterogeneous mass is present.B. CT scan (10-mm collimation) obtained at the level of the suprahepatic inferior vena cava depicts a pleural mass lesion (arrows) with low attenuation.C. T1-weighted MR image obtained at a similar level to A shows a mass lesion with high-signal intensity.D. T2-weighted image depicts a slightly heterogeneous high-signal lesion.E. Photomicrograph (original magnification, × 1; hematoxylin-eosin staining) shows an invasive tumor bud (arrowheads) penetrating the capsule where there is no fibrous sleeve.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698058&req=5

Figure 5: Type-B2 thymoma in a 35-year-old woman.A. Enhanced 10-mm-collimation CT scan obtained at the level of the right interlobar pulmonary artery shows that in the anterior mediastinum, a slightly attenuated heterogeneous mass is present.B. CT scan (10-mm collimation) obtained at the level of the suprahepatic inferior vena cava depicts a pleural mass lesion (arrows) with low attenuation.C. T1-weighted MR image obtained at a similar level to A shows a mass lesion with high-signal intensity.D. T2-weighted image depicts a slightly heterogeneous high-signal lesion.E. Photomicrograph (original magnification, × 1; hematoxylin-eosin staining) shows an invasive tumor bud (arrowheads) penetrating the capsule where there is no fibrous sleeve.
Mentions: According to Tomiyama et al. (4), smooth contours and a round shape most strongly suggest a type-A tumor (Table 2) (Fig. 2); type-C tumors are significantly larger than types A and B2 (Figs. 2, 5, 7, 8); irregular contours and mediastinal lymphadenopathy are most suggestive of type C (Figs. 7, 8). Calcification is more frequently seen in type-B1, B2, and B3 tumors than in type AB and type C (Fig. 6). A high degree of homogeneous enhancement tends to indicate type A or AB (Fig. 2); heterogeneous enhancement is seen more often in types B3 and C (Fig. 8). Mediastinal lymphadenopathy is present in 43% of type C tumors, 7% of type AB, but not in other types of thymic epithelial tumors. This feature has, however, been found to be of limited value in differentiating types AB, B1, B2, and B3.

Bottom Line: Thymic epithelial tumor is a distinctive pathologic entity exhibiting variable histologic features and heterogeneous oncologic behavior.Among the various classification systems, that of the World Health Organization has been adopted because of good correlation between histologic appearance and oncologic behavior.However, imaging findings among the various types overlap to some extent, and the ability of imaging studies to differentiate types AB, B1, B2, and B3 is limited.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

ABSTRACT
Thymic epithelial tumor is a distinctive pathologic entity exhibiting variable histologic features and heterogeneous oncologic behavior. Among the various classification systems, that of the World Health Organization has been adopted because of good correlation between histologic appearance and oncologic behavior. Radiologically, a smooth contour and round shape are most suggestive of a type-A tumor, whereas an irregular contour most strongly suggests type C. Pleural seeding is rare in type-A and AB tumors; calcification is suggestive of type B. Type-C tumors are significantly larger and more commonly associated with lymphadenopathy than type B3. At T2-weighted MR imaging, lobular internal architecture is more prominent in types B1, B2, and B3 tumors than in others. However, imaging findings among the various types overlap to some extent, and the ability of imaging studies to differentiate types AB, B1, B2, and B3 is limited.

Show MeSH
Related in: MedlinePlus