Metastatic Hemorrhagic Tumors

Fig. 6.2 Invasive pulmonary aspergillosis in an 11-year-old boy with acute lymphocytic leukemia and neutropenia. (a, b) Lung window of CT (5.0-mm section thickness) scans obtained at levels of the inferior pulmonary vein (a) and liver dome (b), respectively, shows nodules (arrows) with halo sign in both lungs. Also note ground-glass opacity along bronchovascular bundles. (c) High-magniÞcation photomicro-

graph of pathologic specimen obtained from the left lower lobe with wedge resection by using video-assisted thoracoscopic surgery discloses necrotic abscess containing blue area of fungal colonization (arrows) in central portion of lesion. Fungal organisms extend to pleural space (open arrows)

Metastatic Hemorrhagic Tumors

Pathology and Pathogenesis

The capillary bed of the lung is an effective filter of tumor emboli, and secondary tumors in the lung are therefore the usual immediate source of metastases in other organs. The terminal bronchopneumonia with abscess or hemorrhage adjacent to the tumor may also follow airway obstruction.

Symptoms and Signs

Due to peritumoral hemorrhage secondary to the fragility of neovascular tissue, cough, blood-tinged sputum, and dyspnea can occur in the patients with lung metastases from

hypervascular tumors. Symptoms and signs related to the primary site of malignancy usually exist.

CT Findings

On CT, hematogenous metastatic nodules range from a few millimeters to several centimeters in diameter, and when multiple they are usually of varying in size. The nodules tend to be most numerous in the outer third of the lungs, particularly the subpleural regions of the lower zones, and have a random distribution within the secondary pulmonary lobules. Metastases most commonly are round and have smooth margins. Metastatic hemorrhagic tumors such as angiosarcoma, Kaposi sarcoma, choriocarcinoma, and melanoma have a halo of ground-glass opacity surrounding nodules (Figs. 6.3 and 6.4) [2, 4].