Thoracic Imaging 2003 - Society of Thoracic Radiology

WEDNESDAY
228
Thoracic Metastases from Bronchogenic Carcinoma
Autopsy incidence 7-50%
Clinical incidence low except for SCAC and BAC
Routes via: K systemic vv from systemic metastases (liver)
K pulmonary lymphatics and R lymphatic duct
to R subclavian v
K bronchial vv to systemic vv
K pulmonary vv to systemic aa (bronchial aa)
K pulmonary a (primary invasion)
K airways (BAC)
Thoracic Metastases from Colorectal Carcinoma
• Incidence 10-20%
• Single or multiple nodules – cavitation
• Endobronchial
• Single nodule an equal chance of being a primary or secondary
neoplasm
• Most have liver mets
• Survival after resection 40% at 5 years, 30% at 10 years
Thoracic Metastases from Renal Cell Carcinoma
• 30-45% of patients with metastatic RCC to lung will have no
kidney symptoms
• >60% involve thorax at some time (autopsy incidence 55-
77%)
*single or multiple pulmonary nodules; embolic occlusion of
pulmonary arteries; endobronchial (stimulate bronchogenic
Ca)
hilar/mediastinal adenopathy (7.2-28.2%) – pseudosarcoid;
isolated R lower hilar
pleural
• Late appearance of metastases (up to 50 years)
• Spontaneous disappearance of metastases (postnephrectomy)
Thoracic Metastasis from Testicular Neoplasms
• Incidence of pulmonary metastases – chorio Ca 81%, seminoma
19%, nonseminoma 18%.
• (Seminoma) – mediastinal lymphadenopathy – subcarinal,
post med
• (Teratoma) – single or multiple pulmonary nodules; endobronchial;
low attenuation masses (CT)
• Chemotherapy – metastatic teratoma – cure rate > 70%
• Persistent nodules after chemotherapy
Resistant metastases
Necrotic/fibrotic sterile metastases }Tumour Markers
Benign well-differentiated teratomas (25%)} Normal
(selective destruction of malignant elements)
Nodules – Not Too Concerning
• Ill-defined
• Small
• Subpleural
• Calcified
• Clusters or groups in one area
• Associated with bronchial abnormalities (wall thickening,
mucoid impaction, dilatation)
• Tree-in-bud
• Centrilobular
• No history of malignancy
Nodules – More Concerning
• Well-defined
• Small or larger
• Random
• Growing
• History of malignancy
Accuracy of Imaging
• 37%
• Underestimated in 39%
• Overestimated in 24%
Thoracic Metastases from Prostate Carcinoma
Clinical incidence 4.9-6.7%
Autopsy incidence 13-53%
• Lymphangitic carcinomatosis
• Nodules
Pleural effusion } Unusual
Adenopathy }
• Endobronchial
• Most patients have associated bony metastases
• Immunoperoxidase stain specific for prostatic acid phosphatase
Multiple Pulmonary Leiomyosarcomas
(Benign Metastasizing Fibroids)
• Usually in females with a history of hysterectomy for
fibroids
• Multiple well defined noncalcified pulmonary nodules
• Slow progression (regression during pregnancy) – good prognosis
• Probably metastatic low grade leiomyosarcoma rather than
hamartoma
Thoracic Metastases from Cervical Carcinoma
Incidence 1.7-9.1%
Autopsy incidence 15-25%
• Single or multiple nodules – cavitation
• Adenopathy
• Pleural
Thoracic Metastases from Ovarian Carcinoma
Incidence 1-34%
• *Pleural effusion (via diaphragmatic lymphatics)
• Lung nodules (interstitial or alveolar)
• Lymphangitic
Thoracic Metastases from Gestational Trophoblastic
Neoplasms
Hydatidiform mole, invasive mole, choriocarcinoma
Choriocarcinoma – mets common – incidence 45-87%
Remission rate after chemotherapy high (up to 88%)
• Multiple well-defined nodules
• Multiple poorly-defined alveolar nodules (hemorrhage) –
halo sign on CT
• Embolic occlusion of pulmonary arteries
pulmonary infarction
pulmonary arterial hypertension
• Arteriovenous shunting
• Sterile metastasis – HCG normal
• Spontaneous remission after removal of primary