Organ Systems, Pulmonary

Neoplastic Lung Classification – Resection Specimens

The following is a combination of the IASLC/ATS/ERS lung tumor classification for adenocarcinoma in resection specimens and the general WHO 2004 classification.  See Neoplastic Lung Classification – Biopsy for categorization in small biopsy samples.

  • Small Cell Carcinoma
  • Adenocarcinoma (IASLC/ATS/ERS)
    • Pre-invasive Lesions
      • Atyipcal Adenomatous Hyperplasia (AAH)
    • Adenocarcinoma In-SItu (≤3 cm lepidic predominant)
      • Non-mucinous
      • Mucinous
      • Mixed mucinous/non-mucinous
    • Minimally Invasive Adenocarcinoma
      • ≤3 cm lepidic predominate lesion (+)
      • ≤0.5 cm invasion
    • Invasive Adenocarcinoma
      • Lepidic predominant
        • Non-mucinous
        • > 0.5 cm invasion
      • Acinar predominant
      • Papillary predominant
      • Micropapillary predominant
      • Solid predominant with mucin production
    • Variants of Invasive Adenocarcinoma
      • Invasive mucinous adenocarcinoma 
        • formally mucinous BAC
      • Colloid
      • Fetal
        • Low-grade
        • High-grade
      • Enteric
  • Squamous Cell Carcinoma
    • Squamous Cell Carcinoma
    • Non-Small Cell Carcinoma, favor Squamous Cell Carcinoma
      • Used when stains support the diagnosis, but morphology is limited
  • Large Cell Carcinoma
    • Non-Small Cell Carcinoma, Not Otherwise Specified (NOS)
    • Non-Small Cell Carcinoma with Neuroendocrine Morphology (Positive Neuroendocrine Markers), possible Large Cell Neuroendocrine Carcinoma (LCNEC)
    • Non-Small Cell Carcinoma with Neuroendocrine Morphology (Negative Neuroendocrine Markers)
      • Comment should be made that a LCNEC is suspected but NE markers are not expressed
  • Adenosquamous Carcinoma
    • Non-Small Cell Carcinoma, with mixed Squamous and Adenocarcinoma Patterns
      • Comment should be made that this could represent an adenosquamous carcinoma.
  • Spindle Cell Carcinoma
References

Travis WD, Brambilla E, Noguchi M, Nicholson AG, Geisinger KR, Yatabe Y, et al. International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma. J Thorac Oncol. 2011;6: 244–285. doi:10.1097/JTO.0b013e318206a221