thoracic neoplasms Flashcards
what is the mediastinum
anatomic space located between the lungs that contains all principal tissues and organs of the chest except the lungs
what are the borders of the anterior mediastinum
posterior sternum and anterior aspect of the great vessels and pericardium
what are the contents of the anterior mediastinum
- thymus
- internal mammary arteries
- lymph nodes
- connective tissue
- fat
what are the MC etiologic masses in 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
what are the borders of the middle mediastinum
- ventral border: anterior aspect of the pericardium, great vessels and trachea
- dorsal border: posterior pericardium, anterior esophagus
What are the 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 )
what are the borders of the posterior mediastinum
- everything behind the posterior pericardium
what are the contents of the posterior mediastinum
- descending thoracic aorta
- esophagus
- thoracic duct
- azygos and hemiazygos veins
- sympathetic chains
- posterior group of mediastinal lymph nodes
- spine
what are the MC etiologic masses of the posterior mediastinum
- Neurogenic tumors, meningocele, meningomyelocele
- Gastroenteric cysts, esophageal diverticula/tumor
- Hiatal hernia, hernia through foramen of Bochdalek
- Extramedullary hematopoiesis
when are most mediastinal masses found?
incidentally 50% of the time
what is required when a mediastinal mass is suspected
a comprehensive H&P with a full ROS
what physical exam systems are particularly important to be observed in mediastinal masses
- head/neck
- upper extremity
- chest
- abdomen
- all lymph nodes
- scrotal/testicular exam in males
what is the mediastinal mass effect
direct involvement or compression of normal cardiothoracic structures
what are symptoms associated with the mediastinal mass effect?
- lungs - stridor, hoarseness, shortness of breath, dyspnea, cough, hemoptysis, retrosternal chest pain
- esophagus - dysphagia
- vascular compression - facial and/or extremity swelling
- heart - cardiac compression, hypotension
- sympathetic chain - horners syndrome
what is the mediastinal mass effect on the sympathetic chain
causes horners syndrome:
remember this is characterized by PAM Horner!!
P - Ptosis (drooping of the upper eyelid)
A - anhidrosis (absence of sweating of the face)
M - miosis (constriction of pupil)
what symptoms are more often related to malignant lesions such as lymphoma and paraneoplastic disorders
systemic (constitutional) effects
- fever
- night sweats
- weight loss
What is the imaging that is obtained with a mediastinal mass
initial - CXR - PA/lateral
CT chest w IV contrast - provides information on location, size, relationship to other structures, and tissue characters
(I feel like this is CXR to confrim that there is a nodule, then CT to learn more about the nodule)
what are some additional imaging options for mediastinal masses and when would you obtain these types of images
- barium swallow - suspected esophageal disease
- doppler US, CT/MRI - vascular etiology
- thyroid scan and uptake - intrathoracic goiter
- PET scan or PET-CT - suspected lymphoma or malignancy
- testicular/ovarian US - to assess for primary site of germ cell tumor
what are laboratory evaluations that should be done in evaluation of mediastinal masses
- tumor markers if thymoma or germ cell tumors are suspected
- anti-acetylcholine receptor antibodies (+ in thymic tumors)
- alpha fetoprotein and beta human chorionic gonadotropin (+ in germ cell tumors)
- lactate dehydrogenase (high in seminomas and lymphoma)
what labs are positive in thymic tumors
anti-acetylcholine receptor antibodies
what labs are elevated with germ cell tumors
alpha fetoprotein and beta human chorionic gonadotropin
what labs are elevated with seminomas and lymphoma
lactate dehydrogenase
what other laboratory studies could be done in evaluation of mediastinal masses
- lymphoma workup
- thyroid workup
- biopsy
what are the three types of biopsies for mediastinal masses
- percutaneous
- endobronchial
- surgical mediastinoscopy with biopsy
what is a percutaneous biopsy
uses CT guidance for exact location of biopsy
when is a encobronchial biopsy obtained
- appropriate if mediastinal mass is located immediately adjacent to an airway
- using endobronchial US can improve yield of diagnostic procedure
when are surgical mediastinoscopy biopsies obtained
- small tumors that can be resected at the time of biopsy
- large masses that are unresectable to obtain biopsy
what is the treatment for mediastinal masses
Treatment and prognosis depend on the underlying cause of the mediastinal mass
so I assume we dont gotta know! yayyyy
what are solitary pulmonary nodules also referred to as
coin lesion
what are the characteristics of a solitary pulmonary nodule
- less than/equal to 3 cm (30mm)
- isolated and round opacity
- surrounded by normal lung
- not associated with infiltrate, atelectasis, adenopathy
what is the etiology of solitary pulmonary nodules
they can be benign or malignant but MOST are benign
what are the non-malignant (Benign) causes of solitary pulmonary nodules
- infectious granulomas (80% of benign SPN)
- benign tumors (hamartomas)
- pulmonary AV malformation
what are the MC organisms causing infectious granulomas
- endemic fungi (histoplasmosis, coccidioidomycosis)
- mycobacteria (TB, non TB)
how do non-malignant (benign) SPN appear
well-demarcated and fully calcified or centrally calcified nodule
how do hamartomas typically present clinically and on imaging?
- usually presents in middle age and grows slowly over years
- radiologically and histologically heterogenous
- CXR - popcorn calcifications
- CT - areas of fat or alternating fat/calcifications
what are pulmonary AV malformations
a tangle of connecting arteries and veins
AVOID BIOPSY IN THESE
what are the three categories of malignant causes for SPN
- primary lung cancer
- lung metastasis
- carcinoid tumors
what are the primary lung cancers
- Small Cell Carcinoma - presents centrally
- Adenocarcinoma - present peripherally
- Squamous Cell Carcinoma - presents centrally
- Large Cell Cancer - anywhere but often more peripheral
how do lung metastasis usually present ?
multiple nodules
what are the MC pulmonary metastises
- melanoma
- sarcoma
- carcinomas
of the: - bronchus
- colon
- breast
- kidney
- testicle
what type of carcinoid tumors are MC
endobronchial
20% are present peripherally
what are cancer risks that should be looked for in patient history
- Smoking (increases with the pk yr hx)
- Increasing age (risk increases beginning at age 35)
- Family history
- Female sex
- Emphysema
- Previous malignancy
- Environmental - asbestos
what does comparison of a previous CXR determine when assessing a SPN
- nodule stability
- chance of malignancy
when is a repeat CXR prior to ordering CT indicated
- suspected nodule that is likely a nipple shadow (repeat with nipple markers)
- evidence of infection (repeat in 6-8 weeks)
- nodule characteristics are pathognomonic for benign lesions
what does CT help to assess as far as malignancy risk factors
- Size
- Location
- Attenuation
- Calcification
what size nodules correlate to malignancy rates
- Nodules <5 mm: <1%
- Nodules 5 to 9 mm: 2-6 %
- Nodules 8 to 20 mm: 18%
- Nodules >20 mm: >50 %
- larger nodules often have higher malignancy rates
what nodule location has increased probability of being malignant
nodules found in the upper lobe
what are the possible attenuations of SPN on CT imaging
- solid - MC found and less likely to be cancer
- subsolid - higher likelihood of cancer (can be ground glass nodules which have no solid component, or part-solid nodules which is combo of ground glass and solid)
How does shape differ between benign and malignant lesions
- benign lesions are smooth, with well defined edge
- malignant are ill-defined, lobular or spiculated in appearance; may have a peripheral halo on CT
how does growth differ from malignant to benign SPN
- malignent - growth seen on serial imaging (3-12 mo)
- benign - solid nodule stable for 2 years, subsolid nodule stable for 5
how does lesion calcification differ from benign and malignant lesions
- benign lesions have dense calcifications
- malignant lesions are associated with sparser calcification (stippled or eccentric patterns)
what is the management for SPN
based on probability of malignancy!
what is the solitary pulmonary nodule malignancy risk calculator
estimates the probability that a lung nodule will be diagnosed as cancerous within a 2-4 year f/u period
what is considered high malignancy
- > 30mm nodule
- <30mm and >60% solitary pulm nodule malignancy risk (based off of the calculator)
what is considered low and intermediate risk for malignancy
- low - <30mm and <5% SPN malignancy risk
- intermediate - <30 mm and 5-60% SPN malignancy risk
what treatment is reccommended for SPN that have high malignancy risk
resection
what is the treatment reccomendation for SPN that is low probability of malignancy
“watchful waiting” with serial CT scans
frequency of scanning depends on size of nodule and risk for cancer
what is the management for intermediate probability malignancy risk SPN
controversial recommendations (yay)
options include:
- sputum cytology
- PET scan
- refer for biopsy/tissue sample