Pulmonary Pathology III Flashcards
Most common lung cancers
Adenocarcinoma (38%)
Squamous cell carcinoma (20%)
Small cell (neuroendocrine) carcinoma (14%)
Large cell carcinoma (3%)
What is the progression of normal lung tissue to adenocarcinoma?
- Normal
- AAH (atypical adenomatous hyperplasia)
- AIS (adenocarcinoma in situ)
- Adenocarcinoma
Atypical adenomatous hyperplasia (AAH) size:
Histological appearance:
<5 mm
Dysplastic pneumocytes present along alveoli w/ some interstitial fibrosis. Leads to AIS.
Adenocarcinoma in situ (AIS) size:
Histological appearance:
<3 cm
Dysplastic pneumocytes confluently growing along along alveoli. Follows AAH.
Pulmonary adenocarcinoma shows which structures as malignant?
What does it arise from?
Glands invade the surrounding lung tissue.
Can arise from precursors or develop de novo.
What does Mucinous Adenocarcinoma mimic?
Pneumonia
What is the progression of squamous carcinoma?
- Normal epithelium
- Squamous metaplasia
- Squamous carcinoma in situ
- Invasive squamous carcinoma
What people are more likely to get squamous carcinoma?
More common in men, strong correlation w/ smoking.
Where does squamous carcinoma tend to begin?
Centrally
What key histological characteristic suggests squamous carcinoma?
Keratin pearls and orange cytoplasm
Small cell (neuroendocrine) carcinoma
What is the grade of the malignancy?
Almost always associated w/ smoking.
High rate of mets.
Neuroendocrine carcinoma grade 3.
What are the treatment recommendations for Small cell (neuroendocrine) carcinoma?
Surgery not recommended if metastatic to LNs.
Specific chemo is available. Good response to chemo and radiation, but there is a high rate of recurrence.
What molecular markers can be used to identify Adenocarcinoma?
EGFR
ALK
PDL-1
What paraneoplastic syndrome is associated w/ squamous carcinoma?
Hypercalcemia: PTH-related peptide
What paraneoplastic syndromes are associated w/ Small cell carcinoma?
SIADH - too much ADH secretion.
Cushing’s syndrome - secretion of ACTH.
Why might Horner’s syndrome develop in a patient with a pulmonary malignancy?
SX of Horner’s syndrome
In superior lung cancers where they can affect the cervical sympathetic plexus.
Enophthalmos - sunken eye ball
Ptosis - drooping of eyelid
Miosis - small pupil
Anhidrosis - no sweating on IL side of face
What kind of tumor is Diffuse pulmonary neuroendocrine cell hyperplasia (DIPNECH)?
What detects them?
What is their size?
Neuroendocrine tumor.
High-res CT.
<5 mm (“tumorlets”).
What kind of tumor is a carcinoid tumor?
What makes these tumors important?
What is their size?
Neuroendocrine tumor.
5 mm or bigger.
Capable of metastasizing.
How are carcinoid tumors classified?
Indolent - neuroendocrine carcinoma grade 1.
Atypical carcinoid tumor is classified as:
What is the likelihood of mets?
What are the chances of survival?
Neuroendocrine tumor grade 2.
Increased rate of mets.
Lower survival rate (but better than SCC).
How does atypical carcinoid tumor and carcinoid tumor differ?
Atypical carcinoid tumors have:
Increased mitotic activity
Necrosis
Disorderly growth
What are the SX of carcinoid syndrome?
Flushing, diarrhea, cyanosis.
5-year survival rates for:
Carcinoid tumors (NE carcinoma grade 1)
Atypical carcinoid tumors (NE carcinoma grade 2)
Small cell carcinoma tumors (NE carcinoma grade 3)
Carcinoid tumors (NE carcinoma grade 1) - 95%
Atypical carcinoid tumors (NE carcinoma grade 2) - 70%
Small cell carcinoma tumors (NE carcinoma grade 3) - 5%
What makes up a pulmonary hamartoma?
What is it called when seen on CT?
Fibrous tissue w/ benign glandular epithelium around hyaline cartilage.
“Coin” lesion.
Lymphangioleiomyomatosis (LAM) occurs in:
What LoF is it associated with?
What is the pathogenesis?
What type of cells are found in the BX?
What else does it present w/ often?
Young women.
TSC2.
Proliferation of cells creating cystic spaces.
Modified SM cells, which are positive for melanoma markers (HMB-45). Perivascular epithelioid cells.
Pneumothorax, due to “popping” of the cystic space.
What is the most common cause of transudative (liquid) pleural effusions?
Heart failure
What are the most common causes of exudative (inflammatory) pleural effusions?
Infection
Malignancy
What makes up an empyema?
What structures does it almost always create?
What does the fluid look like?
An inflammatory exudate w/ accumulation of pus, usually from a bacterial infection.
Loculations - web-like traps for fluid.
Thick, yellow. Will have neutrophils and bacteria.
Which patients are at greatest risk for primary (idiopathic) pneumothorax? How?
Young pts. via rupture of subpleural blebs.
What causes a tension pneumothorax?
Injury to chest wall resulting in one-way valve allowing air into the pleural space, but not out.
It is expansion of the chest wall, but not necessarily the lungs, that is responsible for respiration.
In a closed system, air is a space-occupying lesion.
What can cause a secondary pneumothorax?
Cystic infections Cystic tumors Rupture of blebs Trauma Positive-pressure ventilation
What is the pressure differences in the pleural cavity compared to atmospheric in primary vs. tension pneumothorax?
Primary - pleural cavity pressure < atm.
Tension - pleural cavity pressure > atm.
Solitary fibrous tumor are what kind of tumors? Where are they located?
What is its shape?
Benign (when small and pedunculated) tumors of the pleura. Larger ones may behave like sarcomas.
CIrcumscribed.
What are 3 variants of Mesothelioma?
What is a stain that can help distinguish it from Adenocarcinoma?
Epithelioid, Sarcomatoid, Mixed.
Calretinin.
How is Mesothelioma treated?
Is it responsive to chemo/radiation?
What is the prognosis?
Difficult to treat, as it cannot be excised surgically.
Limited responsiveness to chemo/radiation.
Most pts. will not live after 2 yrs.
Which malignancies develop proximally, in various locations, and peripherally?
Proximal - squamous cell carcinoma
Various - small-cell NE carcinoma
Peripherally - adenocarcinoma
Which cancer exhibits some degree of the 2-hit theory?
What other lung cancer can it exist with?
Small-cell NE carcinoma: Rb goes first, then p53.
Can exist w/ squamous cell carcinoma.
What should be considered if a pt. has pneumonia-like SX, but does not respond to any therapy?
Mucinous adenocarcinoma
How is mucinous adenocarcinoma differentiated from AIS?
Size. Mucinous adenocarcinoma > 3 cm.
What is the course of action once a DX of small-cell NE carcinoma is made?
PET CT due to high likelihood of mets.
If the effusion is bloody, what would be a concern?
If effusion is pale-yellow, what is a likely DX?
If effusion is white and chalky, what is a concern?
Metastases
HF, a transudative effusion
A neoplasm that blocks thoracic duct. Or post-op where the thoracic duct is clipped.
