(17.1) Pulmonary Pathology III (Singh) Flashcards
What is THE most significant risk factor for aquiring lung cancer?
Tobacco use in terms of duration and intensity
What is a “pack-year”?
(packs smoked per day) x (years of use)
ex: 1 pack a day for 35 years = 35 pack years
2 packs a day for 30 years = 60 pack years
What are other risk factors for aquiring lung cancer?
Radiation
Uranium
Asbestos
Radon
What genetic factors can mitigate carcinogen exposure?
P450 polymorphisms
Genes responsible for DNA repair
What are the major classifications of lung tumors?
“Small cell” vs. “Non-small cell”
What is the origin of squamous-cell carcinoma?
Coming from the respiratory epithelium
Arises from metaplastic adaptive phenomenon
What is the origin of small-cell carcinoma?
Neuroendecrine cells
What is the origin of adenocarcinoma?
Type II pneumocytes
Describe the 4 steps in the progression of pulmonary adenocarcinoma
Normal –> AAH –> AIS –> Adenocarcinoma
Atypical adenomatous hyperplasia (AAH)
Size?
Describe appearance:
Less than or equal to 5mm
Dysplastic pneumocytes present along alveoli with some interstitial fibrosis
Adenocarcinoma in Situ (AIS)
Size?
Describe appearance:
<3cm
Dysplastic pneumocytes confluently growing along alveoli
What is the most common form of lung cancer?
Pulmonary adenocarcinoma
How can you tell histologically that a lung biopsy has pulmonary adenocarcinoma?
Histology shows malignant GLANDS invading the lung tissue
What is the pathology?
Mucinous adenocarcinoma
Why is mucinous adenocarcinoma frequently misdiagnosed?
CAN MIMIC PNEUMONIA on CXR
What is the progression of squamous carcinoma?
Normal bronchial epithelium –> Squamous metaplasia –> Squamous carcinoma in situ –> Invasive squamous carcinoma
Demographic of squamous carcinoma?
Men
Smokers
Where in the lungs does squamous carcinoma occur?
Centrally
What are these?
KERATIN PEARLS
Diagnostic for squamous carcinoma
What does an orange cytoplasm represent in cytology?
Orange cytoplasm = keratin
That means wer are dealing with squamous carcinoma
What is the pathology?
Small cell *neuroendocrine* carcinoma
What is one of the newer methods physicians use for “typing” tumors?
Molecular testing
Has implications for how you can treat them
Squamous carcinoma is correlated with….
Hypercalcemia
PTH-related peptide
What is small cell carcinoma correlated with?
SIADH (Syndrome of inappropriate ADH secretion)
Cushing’s syndrome (secretion of ACTH)
How is Horner’s syndrome related to lung oncology?
Superior lung tumor can impinge on nervous system and induce horners
What is DIPNECH?
“Diffuse interstitial pulmonary neuroendocrine cell hyperplasia”
Nodules
LESS THAN 5mm
What is a carcinoid tumor?
5mm or larger
Metastasize
Indolent
What is atypical carcinoid tumor?
(Neuroendocrine tumor grade 2)
As opposed to carcinoids:
- Increased mitotic activity
- Necrosis
- Disordered growth
INCREASE RATE OF METASTASIS
5 year survival rates for neuroendocrine tumors
State which has a:
95%
70%
5%
Survival rate
Carcinoid tumors (neuroendocrine carcinoma grade 1) = 95%
Atypical carcinoid tumors (neuroendocrine carcinoma grade 2) = 70%
Small cell carcinoma (neuroendocrine carcinoma grade 3) = 5%
Inflammatory myofibroblastic tumors are associated with what mutation?
ALK gene rearrangements
What is the demographic for lymphangioleiomyomatosis (LAM)?
Young women
What is the associated loss of function mutation associated with lymphangioleiomyomatosis (LAM)?
Loss of function of TSC2
What is the difference b/w transudative and exudative fluid?
Transudate = clear fluid
Exudate = high protein content
What would cause the following pleural effusion samples?
Left, Center, Right
Left = bloody effusion
Middle = obstructed throacic duct
Right = heart failure
What is an empyema?
Inflammatory exudate w/ accumulation of pus in the pleural space
bacterial infection
*Hallmark = Creating loculations which are web-like traps for fluid
What is a pneumothorax?
The presence of air or gas in the cavity b/w the lungs and the chest wall, causing collapse of the lung
What is a tension pneumothorax?
Injury to the chest wall resulting in a one-way valve allowing air into the pleural space but not OUT
What is a hallmark feature on a CXR that is indicative of tension pneumothorax?
Mediastinal shift
What is a solitary fibrous tumor?
Benign when small and pedunculated plural tumor
What is mesothelioma?
Associated with asbestos exposure
What is the special stain used to distinguish adenocarcinoma from mesothelioma?
CALRETININ
