Module 10 Part 2 - Malignant Respiratory Cytology

Question 1

Pulmonary Neoplasms

Answer 1

Multiple sputum samples are best in detecting lesions which arise centrally in the lung such as squamous cell carcinoma and small cell carcinoma
Peripheral and subpleural lesions are best sampled using bronchial brush and wash specimens, bronchoalveolar lavage and the fine needle aspiration technique

Question 2

Lung Cancer and Smoking

Answer 2

Progressive alteration in epithelium lining the respiratory tract in habitual smokers
Linear correlation between intensity of exposure to cigarette smoke and the development of the epithelial abnormalities
Squamous metaplasia => dysplasia => CIS => invasive carcinoma

Question 3

Primary Lung Cancer

Answer 3

95% of primary lung cancers are derived from bronchial epithelium:
- bronchogenic carcinoma
5% fall into the miscellaneous category and include:
- bronchial carcinoma tumour
- mesothelioma
- mesenchymal tumours
- lymphomas

Question 4

Bronchogenic Carcinoma - Histological Subtypes

Answer 4

Non small cell lung carcinoma (NSCLC)
Squamous cell carcinoma (SCC)
Adenocarcinoma (ACA)
Large cell undifferentiated carcinoma (LCLC)

Question 5

Cytology of Squamous Cell Carcinoma (SCC)

Answer 5

Often single cells predominate
Striking pleomorphism with sharp cell outlines
Chromatin irregularly dispersed and densely hyperchromatic
Karyopyknosis
Irregular keratinization
Irregular cytoplasmic thinning manifested as caudate cells and spindle cells
Ghost cells
Abnormal keratin pearl formations
Background of necrosis

Question 6

SCC - DDx

Answer 6

Repair
Squamous metaplasia
Cavitating lung infections 
- e.g. mycetoma
Pulmonary infarction
Mesothelial cells
Vegetable cells
Radiation/chemotherapy effect
Contamination by Ca upper airway

Question 7

SCC - False Positive/Negative Dx

Answer 7

False positive Dx
- overinterpretation of reparative or metaplastic changes
False negative Dx
- only necrotic/inflammatory material
- granulomatous reaction to keratin

Question 8

Histology of Adenocarcinoma

Answer 8

Adenocarcinoma may be subdivided into:
- acinar
- papillary
- bronchioloalveolar subtypes (a pattern defined as growth of cuboidal cells or columnar tumour cells along alveolar or fibrovascular septa)
- mixed acinar and papillary
Majority of adenocarcinomas develop on the periphery of the lung and may involve the overlying pleura

Question 9

Lipidic AdenoCa - Cytology

Answer 9

Ball like clusters of cells
Papillary fronds
Nuclei round to oval with bland, finely granular chromatin
Nucleoli but inconspicuous
Single cells may bear a strong resemblance to alveolar macrophages, which may be present in large numbers
Cytoplasmic villi may mimic cilia

Question 10

Small Cell Anaplastic Ca (SCA)

Answer 10

Very small cells arranged in loose clusters with some dispersed single cells
Individual cell is ~1.5 times the size of a lymphocyte
Nuclei are usually round to irregular in shape
Chromatin is hyperchromatic and dense ‘classical salt and pepper’
Karyopyknosis
Extremely scanty cytoplasm
Intercellular nuclear moulding
Fragile cells – smearing artefact/streaking
Mitotic figures
Prominent apoptosis
Abundant background necrosis

Question 11

SCA - DDx

Answer 11

Lymphocytes
Lymphoma
Degenerate bronchial cells
Poorly differentiated SCC/NSCLC

Question 12

Large Cell Undifferentiated Ca

Answer 12

Mixture of large single cells and syncytial groupings
Nuclei round to lobulated with irregularly dispersed, intensely hyperchromatic chromatin
Macronucleoli, may be multiple
Tumour giant cells
Cytoplasmic outline frequently ill defined