Thoracic Neoplasms Flashcards
What is the Mediastinum?
- The anatomic space located between the lungs
- Contains all the principal tissues and organs of the chest except the lungs
- “Arbitrary” compartments for classification and differentiation of diagnosis
what are the compartments of the mediastinum?
- Superior - anything above the heart
- some texts combined with the anterior compartment - Inferior
- Anterior
- Middle
- Posterior
borders of the anterior medistinum
posterior sternum and anterior aspect of the great vessels and pericardium
contents of the anterior mediastinum
Thymus, internal mammary arteries, lymph nodes, connective tissue, fat
MC Etiologic Masses of the anterior mediastinum
- “Terrible T’s”
- Thymoma, Teratoma, Thyroid/Parathyroid tissue - Foramen of Morgagni hernia
- Mesenchymal tumors (lipoma, fibroma)
- Giant lymph node hyperplasia, lymphoma
- Germ cell tumor - seminoma /teratoma
Middle Mediastinum borders
Ventral border: anterior aspect of the pericardium, great vessels and trachea
Dorsal border: posterior pericardium, anterior esophagus
contents of the middle mediastinum
Pericardium, heart, ascending aorta, pulmonary vessels, trachea, lymph nodes
MC Etiologic Masses of the middle mediastinum
- Granulomatous or metastatic lymphadenopathy
- Cysts
- pleuropericardial, bronchogenic, enteric - Masses of vascular origin
- pulmonary artery enlargement (in PH), aortic aneurysm
borders of Posterior Mediastinum
Everything behind the posterior pericardium
contents of Posterior Mediastinum
Descending thoracic aorta, esophagus, thoracic duct, azygos and hemiazygos veins, sympathetic chains, the posterior group of mediastinal lymph nodes and the spine
MC Etiologic Masses of Posterior Mediastinum
- Neurogenic tumors, meningocele, meningomyelocele
- Gastroenteric cysts, esophageal diverticula/tumor
- Hiatal hernia, hernia through foramen of Bochdalek
- Extramedullary hematopoiesis
presentation of mediastinal mass
- Incidental finding in ½ of all cases
- When suspected a comprehensive H&P is required with a full ROS
- PE - head/neck, upper extremity, chest, abdomen, all lymph nodes, scrotal/testicular exam in males
Mediastinal mass effect - direct involvement or compression of normal cardiothoracic structures
what are the presentation?
- Lungs: stridor, hoarseness, shortness of breath, dyspnea, cough, hemoptysis, retrosternal chest pain
- Esophagus: dysphagia
- Vascular compression: facial and/or upper extremity swelling
- Heart: cardiac compression, hypotension
- Sympathetic chain: Horner’s syndrome
Systemic (constitutional) effects are more often related to ? (e.g. lymphoma, paraneoplastic disorders)
what are those sx?
malignant lesions
fever
night sweats
weight loss
imaging (+additional) for mediastinal mass?
- Initial: CXR - PA/Lateral
- CT chest w/ IV contrast - provides information on location, size, relationship to other structures, and tissue characteristics
- Barium Swallow - suspected esophageal disease
- Doppler US, CT/MRI angiography - (CTA/MRA) - vascular etiology
- Thyroid scan and Uptake (Iodine-131 scan) - intrathoracic goiter
- PET scan or PET-CT - suspected lymphoma or malignancy
- Testicular/Ovarian US - to assess for primary site of germ cell tumor
Laboratory Evaluation - Based upon DDx of mediastinal masses
- Tumor markers if thymoma or germ cell tumors are suspected
- Anti-acetylcholine receptor antibodies - positive antibodies in thymic tumors
- Alpha-fetoprotein (AFP) and Beta-human chorionic gonadotropin (beta-hCG) - elevated with germ cell tumors
- Lactate dehydrogenase (LDH) - elevated with seminomas, lymphoma - Lymphoma workup
- Thyroid Workup - TSH, Free T4
- Referral = surgery - cardiothoracic or general
doing this would risk of malignant seeding
in mediastinal mass
biopsying
types of biopsies for mediastinal masses
- Percutaneous
- uses CT guidance for exact location of biopsy - Endobronchial
- appropriate if mediastinal mass is located immediately adjacent to an airway
- using endobronchial US can improve yield of diagnostic procedure - Surgical - Mediastinoscopy with biopsy
- small tumors that can be resected at the time of biopsy
- large masses that are unresectable to obtain biopsy
tx for mediastinal mass
Treatment and prognosis depend on the underlying cause of the mediastinal mass
referred to as a “coin lesion”
Often found incidentally with an asymptomatic clinical presentation
Solitary Pulmonary Nodule (SPN)
≤ 3 cm (30 mm)
isolated and round opacity
surrounded by normal lung
not associated with infiltrate, atelectasis, or adenopathy
these characteristics are associated with what dx?
solitary pulmonary nodule (SPN)
what size is considered a pulmonary mass?
> 3 cm (30mm)
SPN is MCC are benign or malignant?
benign
Non-Malignant (Benign) Causes
- Infectious granulomas (80% of benign SPN)
- Benign Tumors (e.g. Hamartomas)
- Pulmonary AV Malformation
- Usually present in middle age, grows slowly (over years)
- Radiologically and histologically heterogeneous
- CXR - “popcorn” calcification
- CT - areas of fat or alternating fat/calcifications
what type of Non-Malignant (Benign) Cause SPN?
Benign Tumors (e.g. Hamartomas)
Classically appear as a well-demarcated and fully-calcified or centrally calcified nodule
what type of non-malignant cause of SPN?
Infectious granulomas
MCC (pathogens) of infectious granulomas in SPN
MC organisms
Endemic fungi (eg, histoplasmosis, coccidioidomycosis)
Mycobacteria (tuberculous or nontuberculous)
a tangle of connecting arteries and veins
what is this benign cause of SPN
Pulmonary AV Malformation
why Avoid biopsy of Pulmonary AV Malformation?
bleed risk
Malignant Causes of SPN
- Primary lung cancer
- Lung metastasis
- Carcinoid tumors
which primary lung cancers presents more centrally?
Small Cell Carcinoma - presents centrally
Squamous Cell Carcinoma - presents centrally
Most pulmonary metastases presents as ?
multiple nodules
MC Carcinoid tumors?
endobronchial, some (20%) present peripherally
which primary lung cancers present more peripherally?
Adenocarcinoma - present peripherally
Large Cell Cancer - anywhere but often more peripheral
MC pulmonary metastasis
melanoma, sarcoma¹, and carcinomas of the bronchus, colon, breast, kidney, and testicle
cancer risks for SPN?
Smoking (increases with the pk yr hx)
Increasing age (risk increases beginning at age 35)
Family history
Female sex
Emphysema
Previous malignancy
Environmental - asbestos
imaging for SPN
CXR: Compare to previous CXR - Determines nodule stability and chance of malignancy
CT chest w/o contrast: preferred, looks at anatomical features of lesion
Repeat CXR prior to ordering CT is indicated if:
- suspected nodule is likely a nipple shadow - repeat with nipple markers
- evidence of infection - repeat in 6-8 wks
- nodule characteristics are pathognomonic for benign lesion
CT imaging helps to assess malignancy with these risk factors
Size
Location
Attenuation
Calcification
Larger nodules often have (high/low) malignancy rates
what are the measurements-malignancy rate?
Nodules <5 mm: <1%
Nodules 5 to 9 mm: 2-6 %
Nodules 8 to 20 mm: 18%
Nodules >20 mm: >50 %
Nodules found in the upper lobe have what probability of being malignant
increased
attenuation CT imaging assessment for SPN shows? what do they mean?
Solid vs. subsolid
1. Solid- more commonly found and less likely to be cancer
2. Subsolid - higher likelihood of malignancy
- ground-glass nodules ( no solid component)
- part-solid nodules (both ground-glass and solid components)