Lung Cancer - Guidelines for Processing Specimens and Reporting Tumor Stage

Appendix 3 - WHO Classification of Pulmonary Carcinomas

Squamous cell carcinoma*

---

Variants:
    Papillary
    Clear cell
    Small cell
    Basaloid

Small cell carcinoma

---

Variants:
    Combined small cell carcinoma

Adenocarcinoma*

---

Acinar
Papillary
Bronchioloalveolar carcinoma
    non-mucinous (Clara cell/type 11pneumocyte)
    mucinous (goblet cell)
    mixed mucinous and non-mucinous
Solid adenocarcinoma
Adenocarcinoma with mixed subtypes
Variants:
    Well-differentiated fetal adenocarcinoma
    Mucinous ("colloid") adenocarcinoma
    Mucinous cystadenocarcinoma
    Signet ring adenocarcinoma
    Clear cell carcinoma

Large cell carcinoma

---

Variants:
    Large cell neuroendocrine carcinoma
        Combined large cell neuroendocrine carcinoma
    Basaloid carcinoma
    Lymphoepithelioma-like carcinoma
    Clear cell carcinoma
    Large cell carcinoma with rhabdoid

Adenosquamous carcinoma

---

Carcinomas with pleomorphic, sacromatoid or sarcomatous elements

---

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

Carcinoid tumor

---

Typical carcinoid
Atypical carcinoid

Salivary gland tumors

---

Mucoepidermoid carcinoma
    Adenoid cystic carcinoma
Others

* Graded: Well-differentiated, moderately differentiated and poorly differentiated