Cellular classification of bronchogenic carcinomas

(1999 WHO/IASLC Revision)

Preinvasive lesions

• Squamous dysplasia/carcinoma in situ
• Atypical adenomatous hyperplasia
• Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

Invasive Malignant Non-small Cell

Squamous cell carcinoma

Variants:

• Papillary
• Clear cell
• Small cell
• Basaloid
  

Adenocarcinoma

• Acinar
• Papillary
• Bronchioloalveolar carcinoma
• Non-mucinous
• Mucinous
• Mixed mucinous and non-mucinous or indeterminate
• Solid adenocarcinoma with mucin formation
• Mixed

Variants:

• Well-differentiated fetal adenocarcinoma
• Mucinous ("colloid"),
• Mucinous cystadenocarcinoma
• Signet ring
• Clear cell

Large cell carcinoma

• Large cell neuroendocrine carcinoma
• Combined large cell neuroendocrine carcinoma
• Basaloid carcinoma
• Lymphoepithelioma-like carcinoma
• Clear cell carcinoma
• Large cell carcinoma with rhabdoid phenotype

Adenosquamous carcinoma

Carcinomas with pleomorphic, sarcomatoid or sarcomatous elements

• Carcinomas with spindle and/or giant cells
• Pleomorphic carcinoma
• Spindle cell carcinoma
• Giant cell carcinoma
• Carcinosarcoma
• Blastoma (Pulmonary blastoma)

Invasive Malignant Small Cell

Small cell carcinoma

Variants:

• Combined small cell carcinoma