Topic Completed: 1 July 2015

Minor changes: 18 March 2021

Copyright: 2003-2021,, Inc.

PubMed Search: Papillary adenocarcinoma [title] lung

Negar Rassaei, M.D.
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Cite this page: Rassaei N. Papillary. website. Accessed October 25th, 2021.
Definition / general
  • Lung adenocarcinoma is a malignant epithelial neoplasm composed of glandular structures, which includes goblet cell, club (Clara) cell, type II pneumocytes, and bronchial surface epithelial cell types with or without mucin production
  • Bronchial surface epithelial types are also classified as mucinous and non-mucinous variants (WHO: Pathology and Genetics of Tumours of the Lung, Pleura, Thymus and Heart, 2004, Am J Surg Pathol 1997;21:43)
  • In 2011, the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) revised the classification of lung adenocarcinoma and proposed new morphological criteria to provide a uniform diagnostic terminology for multidisciplinary patient management
  • This classification delivers a comprehensive histologic subtyping based on pattern recognition and a semi-quantitative assessment of each pattern in 5% increments to evaluate a single, predominant pattern in invasive adenocarcinomas (J Thorac Oncol 2011;6:244)
  • Different histologic subtypes in lung adenocarcinomas include:
  • Most lung adenocarcinomas demonstrate a mixture of different histologic patterns
  • All described histologic subtypes have prognostic significance, with lepidic subtype harboring the best course, and micropapillary and solid patterns having a more aggressive behavior
  • Lepidic pattern of adenocarcinoma
    • Tumors composed of neoplastic cells along the alveolar lining with no stromal, lymphovascular or pleural invasion, and no intraalveolar tumor cells
    • Based on the 2011 classification, solitary, small tumors measuring 3 cm or less in greatest dimension with pure lepidic pattern and no features of invasion are classified as "adenocarcinoma in-situ" and the term "bronchioloalveolar carcinoma" is no longer used
      • These tumors have nearly 100% disease free survival following complete surgical resection (J Thorac Oncol 2011;6:244)
      • Tangential sectioning of the alveolar lining in adenocarcinoma in-situ should be distinguished from true papillary structures
Microscopic (histologic) description
  • Papillary adenocarcinoma is a subtype of invasive adenocarcinoma defined by presence of papillary structures with true fibrovascular cores replacing the alveolar lining or present within the alveolar spaces
  • The fibrovascular cores are lined by cuboidal to columnar neoplastic cells
  • Psammoma bodies may be present (Am J Surg Pathol 1997;21:43, J Thorac Oncol 2011;6:244)
  • Pure lung papillary adenocarcinoma represents only 3-10% of lung adenocarcinomas, but a papillary component is common in adenocarcinomas with multiple histologic subtypes
  • Based on the new classification, invasive adenocarcinomas with multiple different patterns should no longer be classified as "mixed adenocarcinoma", and each subtype must be assessed and reported semi-quantitatively (in 5% increments)
  • Based on this classification, adenocarcinomas displaying largely papillary structures should be classified as "adenocarcinoma with papillary predominant pattern" (J Thorac Oncol 2011;6:244, Pathol Int 2005;55:619, Eur J Cardiothorac Surg 2015 Mar [Epub ahead of print])
Microscopic (histologic) images

Contributed by Negar Rassaei, M.D.
Adenocarcinoma - papillary subtype Adenocarcinoma - papillary subtype

Adenocarcinoma - papillary subtype

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Various IHC studies

Various IHC studies

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