SFP: Lung Cancers Flashcards
What percentage of lung tumors are carcinomas?
95%
Where do lung cancers fall on the ranking of cancer-related deaths?
1
What percentage of people with lung cancers are active or former smokers?
90%
Does secondhand smoke put you at risk for lung cancer?
Yes, by about 2-fold
What gene involvement is an early event with most lung cancers?
3p tumor suppressor gene deletion
What genes are involved in many non-small cell lung cancers aka adenocarcinoma?
KRAS and EGFR
What is the significance of P450 in lung cancers?
It activates some carcinogens
What tumors are associated with smoking?
Small cell and squamous cell
Describe the origin of carcinoid tumors.
They are not caused by smoking and are neuroendocrine tumors
Describe a typical carcinoid tumor.
There are few mitoses and no necrosis; very rarely metastasizes
Describe atypical carcinoid tumors.
More mitoses and some necrosis; not as malignant as carcinomas but around half metastasize
Where do we tend to see carcinoids in the lung?
In or around the bronchi
What stains can be used to identify carcinoid tumors?
Synaptophysin and chromogranin
Briefly describe origins of small cell carcinoma.
They have a strong relationship to smoking and are neuroendocrine tumors
Where do we normally see small cell carcinoma in the lung?
The hilar region
Describe the gross and microscopic morphology of small cell carcinoma.
They’re big, fast-growing tumors that involve lymph nodes. They have many mitoses, sparse cytoplasm
With which tumors are paraneoplastic syndromes common?
Small cell
What are paraneoplastic syndromes?
Syndromes a patient can exhibit resulting from hormone production by a tumor
What hormones from small cell carcinoma are often involved in paraneoplastic syndromes? What develops from them?
- ACTH: manifestation of Cushing’s disease
- ADH: SIDAH
What hormone is produced by squamous cell carcinomas? What develops as a result?
Parathyroid hormone protein resulting in hypercalcemia
When do we call something non-small cell carcinoma?
When we cannot fully tell the histologic type but know it is not small cell
What is the 5-year survival like in NSCLC?
If it is small and confined, it is about 50%. If it is big or has spread or nodes, it is around 30%
Where do we find squamous cell carcinoma in the lung?
Hilar region
Describe gross morphology of squamous cell carcinoma.
Big tumor with necrosis
Describe histology of squamous cell carcinoma.
Big cells with a lot of cytoplasm with squamous features such as keratin pearls and intercellular bridges
What is squamous cell carcinoma in-situ?
It is limited to the epithelial lining of the lung and does not pass the basement membrane
Where in the lung do we usually see adenocarcinoma?
Peripherally
What is the most common lung cancer in non-smokers and women?
Adenocarcinoma
What gene mutation occurs in about 1/5th of adenocarcinomas?
EGFR
What is the origin of adenocarcinoma?
Epithelial cells
Describe the histology of adenocarcinoma.
Abundant cytoplasm, Nuclei with big nucleoli, malignant gland formation
What is characteristic about adenocarcinoma?
They produce mucin
Describe adenocarcinoma in situ.
They use the alveolar walls as scaffolding to grow on; it does not invade the basement membrane and uses alveolar capillaries for blood supply
Briefly describe large cell carcinoma.
They’re undifferentiated and don’t have features that clearly tell us what the tumor is, and they may have giant cells. They usually metastasize.
What do mitotic figures look like in large cell carcinoma?
Usually very abnormal; the nuclei look different as well
