Illustrate the imaging findings in thoracic metastatic disease in extra-pulmonary malignancy.

Chest is the most common system affected by metastatic disease. The most frequent primary tumours to metas­tasize to the chest include breast cancer, gastrointestinal malgnancy, melanoma, head and neck tumors, and renal cell cancer.

1/Pulmonary metastases Pulmonary involvement may occur via three types of spread: hematogenous (the most common), lymphatic, and endobronchial. These routes of the spread to the lungs explain the imaging features. Single or multiples nodules: Nodules are the most common form of metastatic disease (30 to 50 %), with variable size, and may range from millimeters to several centimeters. They may appear ground glass, solid or mixed solid and ground glass. Calcification or cavitation may also occur. Solid nodules: These nodules are often multiple bilateral, peripheral,...

There are varied sites of metastatic lesions to the tho­rax which acquires more metastases than any other system. Hematogenous dissemination is predominant. CT is a valuable tool to evaluate these lesions. Recognition of the characteristic imaging features in thoracic metastases allows the radiologist to detect the progression or the recurrence of the disease in adequate time for a better survival.

1. Herold CJ, Bankier AA, Fleischmann D. Lung metastases. Eur Radiol. 1996;6(5):596-606. 2. Davis SD. CT evaluation for pulmonary metastases in patients with extrathoracic malignancy. Radiology. 1991 Jul;180(1):1-12. 3. Libshitz HI, North LB. Pulmonary metastases. Radiol Clin North Am. 1982 Sep;20(3):437-51. 4. Milne EN, Zerhouni EA. Blood supply of pulmonary metastases. J Thorac Imaging. 1987 Oct;2(4):15-23. 5. Schlumberger M, Arcangioli O, Piekarski JD, Tubiana M, Parmentier C. Detection and treatment of lung metastases of differentiated thyroid carcinoma in patients with normal chest X-rays. J Nucl...