Lung tumor

Topic Completed: 1 September 2012

Minor changes: 4 July 2020

Copyright: 2003-2019,, Inc.

PubMed Search: adenocarcinoma lung lepidic[TI]

Deepali Jain, M.D.
Page views in 2019: 50
Page views in 2020 to date: 4,442
Table of Contents
Definition / general
Cite this page: Jain D. Lepidic. website. Accessed August 15th, 2020.
Definition / general
  • See also Adenocarcinoma-General topic
  • Refers to growth pattern called lepidic, which arises from and spreads along alveolar walls without invasion
  • Similar to jagziekte, a disease of South African sheep, but jagziekte DNA not identified in human tumors
  • IASLC / ATS / ERS classification (Mod Pathol 2011;24:653): BAC no longer a valid diagnosis
  • WHO definition: adenocarcinoma with bronchioloalveolar pattern and no evidence of stromal, vascular, or pleural invasion, based on complete resection specimen
Bronchioloalveolar carcinoma: how to classify tumors now
    1. ≤ 3 cm, NO stromal, lymphatic, vascular or pleural invasion, no necrosis, no growth patterns other than lepidic:
    • Adenocarcinoma in situ, either serous or mucinous

    2. ≤ 3 cm, with ≤ 5 mm area of stromal invasion or growth pattern(s) other than lepidic:
    • Minimally Invasive Adenocarcinoma (MIA)

    3. > 3 cm OR lymphatic, vascular or pleural invasion OR necrosis OR > 5 mm area of stromal invasion OR growth pattern(s) other than lepidic:
    • Serous: invasive adenocarcinoma, lepidic predominant or
    • Mucinous: invasive mucinous adenocarcinoma

  • Invasion defined as histological subtypes other than lepidic or presence of a myofibroblastic stroma associated invasive tumor
  • For tumors with multiple foci, measure largest dimension on a single slide; do NOT sum invasive foci on all slides
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