Respiratory neoplastic disease

Question 1

What are the classifications of lung cancers?

Answer 1

Small cell carcinoma (20-25%)
Non-small cell carcinoma:
 -Squamous cell carcinoma (25-40%)
 -Adenocarcinoma (25-40%
 -Large cell carcinoma (10-15%)
Combined carcinoma

Question 2

What is small cell carcinoma of the lung?

Answer 2

Occurs in major bronchi and at periphery, rapidly invade bronchial wall and parenchyma (early lymphatic and blond-borne spread so mostly incurable by surgery). Most responsive to chemotherapy. Has worst prognosis and relapses early. - Small, tightly-packed, darkly stained ovoid tumour cells (resemble oats). Absent/inconspicuous nuclei. High mitotic index. Strong relationship to smoking.

Question 3

What is squamous cell carcinoma of the lung?

Answer 3

More common in men, 90% cases are smokers. Arises close to hilum centrally from bronchi usually in area of squamous metaplasia (due to cigarette smoke). Well-differentiated resembles stratified squamous epithelium, characterised by keratin formation and/or intracellular bridges

Question 4

What is adenocarcinoma of the lung?

Answer 4

Most common type in women and non-smokers (but 75% still found in smokers). Peripherally located. Grow slower than SCC but metastasise early and widely. Sometimes associated with scarring e.g. healed TB. Well-differentiated, have obvious glandular elements. 80% contain mucin. Air spaces replaced by cancer

Question 5

What is large cell carcinoma of the lung?

Answer 5

Undifferentiated malignant epithelial tumour. Undifferentiated SCC and adenocarcinoma with no discernible features by light microscopy. HISTOPATHOLOGY: large, anaplastic (cells lose all morphological characteristics of mature cells and their orientation) epithelial cells growing in sheets and islands. NEUROENDOCRINE VARIANT: highly malignant, nests and islands of tumour cells with granular cytoplasm, central necrosis, peripheral palisading (enclosing)

Question 6

What are common lung metastases sites?

Answer 6

Bowel, prostate, breast and kidney. Arrive by blood, lymphatics or direct continuity. Scattered throughout all lobes, peripheral lesions

Question 7

What are pleural tumours?

Answer 7

Can be: 1) secondary metastases (more common than primary tumour) fro lung or breast, 2) primary tumour - malignant mesothelioma

Question 8

What is malignant mesothelioma?

Answer 8

Diffuse lesion that spreads widely in the pleural space, associated with extensive pleural effusion (gas escapes through small hole) and direct invasion of thoracic structures. Plaques on pleural surfaces - Increased incidence in those with exposure to asbestos. Latent period of 25-45 years. No increased risk in asbestos workers who smoke. Pleural mesotheliomas often encase and compress the lung. Absence of mucin, presence of hydraluronic acid, long/slender microvilli
Symptoms: chest pain, dyspnoea, pleural effusions. Treatment: extra-pleural pneumonectomy, chemo, radiotherapy (doesn’t often improve prognosis)