Organ Systems, Pulmonary

Neoplastic Lung Classification – Biopsies

Recommended IASLC/ATS/ERS terminology for tumor diagnoses on small lung biopsies .  See Neoplastic Lung Classification – Resection Specimens for categorization of large excision specimens.

  • Small Cell Carcinoma
    • Small Cell Carcinoma
  • Adenocarcinoma
    • Adenocarcinoma with a lepidic pattern
      • Add comment that an invasive component cannot be excluded
    • Mucinous Adenocarcinoma (with further description on the pattern)
    • Adenocarcinoma with fetal pattern
    • Adenocarcinoma with colloid pattern
    • Adenocarcinoma with signet ring features (describe any other patterns present)
    • Adenocarcinoma with clear cell features (describe any other patterns present)
    • Non-Small Cell Carcinoma, favor Adenocarcinoma
  • 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
    • Poorly differentiated Non-Small Cell Carcinoma with Spindle and/or Giant Cell Carcinoma
      • Comment if there are adenocarcinoma or squamous components.
General Comment

The IASLC/ATS/ERS recommendations came about because the WHO classification of lung tumors is based on excision specimens.  Approximately 70% of patients diagnosed with lung cancer are not surgical candidates, and treatment is based on the biopsy diagnosis.  With leadership from the IASLC/ATS/ERC, more uniformity and reproducibility has been brought to this important area of patient care.  It is the author of this post’s recommendation that anyone signing out lung biopsies should read and know the Travis et al. article cited for this post!

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