Respiratory Neoplasia Flashcards
What are the 4 major types of respiratory tract neoplasia?
- Benign
- Primary Malignant / Bronchogenic Carcinoma
- Secondary Malignant
- Pleural (Mesothelioma)
What are the 2 types of benign respiratory neoplasias?
- Pulmonary Hamartoma
- most common
- cartilage, adipose tissue, smooth muscle, and entrapped epithelium
- more common in older men - Pulmonary Chondroma
- mostly cartilage in a thin fibrous covering
- more common in younger females
What is a secondary malignant respiratory tract neoplasia?
A carcinoma that has spread from cancerous cells elsewhere in the body
Spread can occur by the bloodstream, lymphatic system or by direct spread
What is a pleural neoplasia / mesothelioma?
Location:
- pleural 80%, peritoneum 20%
Aetiology:
- asbestos or occupational exposure
Pathology:
- 20-40 years latency period
- asbestos suppresses TP53 and creates DNA mutation
Distinctive SSX:
- digital clubbing
- diminished breath sounds
What are the 2 main types of primary malignant / bronchogenic carcinomas?
- Non-small cell lung carcinomas (NSLC) - 85%
(arise from epithelial cells within the bronchi) - Small cell lung carcinomas (SCLC) / Neuroendocrine - 15%
(arise from neuroendocrine cells)
What are the 4 types of non-small cell lung carcinomas (NSCLCs)?
- Adenocarcinoma
- Squamous cell carcinoma
- Large cell carcinoma
- Bronchioalveolar cell carcinoma
What are the SSX of non-small cell lung carcinomas (NSCLCs)?
- symptoms occur late or not at all
- maybe a cough
- maybe haemoptysis
Possible obstructive symptoms if tumour obstructs air flow, pleural fluid flow or lymphatic flow:
- stridor
- dyspnoea
- pain
- pleural efusion
- pericardial effusion
Possible compressive symptoms if tumour compresses brachial plexus or Cx sympathetic trunk
- upper limb neuro SSX
- Horner’s syndrome
- Pancoast syndrome
Describe small cell lung carcinomas (SCLCs)
15% of primary malignant / bronchogenic carcinomas
Neuroendocrine:
- arise from neuroendocrine tissue
- have secretory capabilities
Pathology:
- very small cells “oat cells”
- very aggressive
- poor prognosis
What are clinical features caused by an obstructive tumour?
Tumour obstructs airway:
- stridor
- dyspnoea
Tumour invades pleura and obstructs pleural fluid flow:
- pleural effusion
Tumour invades lymphatics and obstructs lymphatic flow:
- pericardial effusion
What are clinical features caused by a compressive tumour?
Tumour compresses brachial plexus:
- neuro SSX upper limb
Tumour compresses Cx sympathetic trunk:
- Horner’s syndrome
Tumour compresses both:
- Pancoast syndrome (neuro SSX upper limb and Horner’s syndrome)
What is Horner’s syndrome?
Compression of the Cx sympathetic trunk supply to the head and face, causing:
- eyelid droop
- pupil constriction
- eyeball retraction
- lack of facial sweating
What are risk factors for primary malignant neoplasia?
Tobacco Silica dust Asbestos Diesel or gas fumes Co-morbid lung disease
What are the 3 mechanisms linking tobacco to neoplasia?
- benzopyrene in tobacco alters TP53 tumour suppressor gene
- oxidative stress caused by chemicals in tobacco causes free radical damage and allows proliferation of neoplastic cells
- process of cellular change:
- goblet cell metaplasia
- basement membrane hyperplasia
- epithelial metaplasia (replacement of ciliated psuedostratified columnar cells with squamous cells)
- carcinoma in-situ
What are 4 paraneoplastic syndromes associated with neuroendocrine / small lung cell cancers?
- hypercalcaemia (release of parathyroid hormone)
- gynaecormastia (release of prolactin)
- Cushing’s syndrome (release of adrenocorticotrophic hormone)
- digital clubbing
(release of TGH)
