Tumors which grew along the intimal surface of the pulmonary arteries.

<p>(A) A resected lung from a mouse. SCID mice were sacrificed 28 days after the injection of SCLs. Many nodules were located on the surface of the lungs. Arrow heads showed some of these nodules. (B) HE staining showed that the tumors were composed of a central area with necrosis and a peripheral zone filled with SCLs. (C) Immunohistochemical staining for MMP-14 revealed that the peripheral area of tumors was positive for MMP-14, and the central necrotic area was negative for MMP-14. (D) Immunohistochemical staining for MMP-2 showed that MMP-2 was weakly positive in the peripheral zone. (Scale bars show 100 µm.)