Malignant .lung pathology

Question 1

Tumours of the lung

Answer 1

possess potentially lethal abnormal characteristic that enables them to invade and metastasize/ to other tissues.

Question 2

Epidemiology of lung cancer

Answer 2

most common cause of cancer death in UK and worldwide. M> F. Cigarette major risk.
5 year survival is between 5-10%

Question 3

Aetiology of lung cancer

Answer 3

Tobacco smoking, occupational/industrial hazards e.g. asbestos, uranium, arsenic, nickel or radiation.
Lung fibrosis: old terminology, scar cancers has been challenged, increased risk in patients with pulmonary fibrosis.
Genetic mutations- EGFR, KRAS, ALK usually seen in people who never smoked.

Question 4

Asbestos

Answer 4

latent period is about 20 years between exposure and development of carcinoma. In combination with cigarette smoking the risk is increased. It is also associated with other respiratory illness. Lung fibrosis and mesothelioma (malignant tumour of the pleura.)

Question 5

Primary: most common (90%) are carcinomas.

4 major types classified based on light microscopy

Answer 5

1) Squamous cell carcinoma 20-30%
2) Small cell carcinoma 15-20%
3) Adenocarcinoma 30-40%
4) Large cell undifferentiated carcinoma 10-15%

Question 6

Metastatic / Secondary lung tumour

Answer 6

Very common, more common that primary tumours. Present as multiple discrete nodules, can be solitary.
Most common are carcinomas from various sites e.g. breast, GI, kidney. Sarcomas, melanomas, lymphomas.
Features: Can present with disseminated disease. Common sites, lymph nodes, pleura liver, bone, adrenal, brain.
Depending on the site, can present with pathological fractures, seizures and lumps in neck. Usually has metabolic effects, weight loss, and lethargy. Electrolytic disturbances, e.g. small cell carcinoma (hypernatremia, hypokalaemia, hypercalcaemia in SCC. Also finger clubbing.

Question 7

Lymphangitis carcinomatosa:

Answer 7

Lymphatic within the lung are diffusely involved by tumour.
Management: Small % of patients are diagnosed with early stage (limited to lung or extension into local nodes) are offered surgery or radical radiotherapy. The majority present with advanced disease, until recent options were limited to chemo or palliate radiotherapy.  Advanced to tailored therapy based on tumour genomics.