Lung
Adenocarcinoma
Invasive mucinous

Editorial Board Member: Andrey Bychkov, M.D., Ph.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Akira Yoshikawa, M.D.

Topic Completed: 4 September 2020

Minor changes: 23 December 2020

Copyright: 2020, PathologyOutlines.com, Inc.

PubMed Search: Invasive mucinous adenocarcinoma[TI] lung

Akira Yoshikawa, M.D.
Page views in 2020: 4,839
Page views in 2021 to date: 2,694
Cite this page: Yoshikawa A. Invasive mucinous. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungtumorinvmucadenocarcinoma.html. Accessed April 18th, 2021.
Definition / general
  • Distinct variant of lung adenocarcinoma with a goblet or columnar morphology and abundant intracytoplasmic mucin
Essential features
  • Rare variant of lung adenocarcinoma with a goblet or columnar morphology and abundant intracytoplasmic mucin
  • No criteria regarding percentage of cells with mucin but typically homogeneous and not admixed with nonmucinous glands
  • Aggressive clinical behavior often associated with intrapulmonary metastasis and recurrence
Terminology
ICD coding
    • ICD-10: C34 - Malignant neoplasm of bronchus and lung
    • ICD-O: 8253/3 - Bronchiolo-alveolar carcinoma, mucinous
Sites
Pathophysiology
Etiology
  • Less associated with smoking than other subtypes of lung adenocarcinoma
Diagrams / tables

Images hosted on other servers:
Survival curves

Survival curves

Clinical features
  • Frequent intrapulmonary metastasis and recurrence
  • Rare extrapulmonary and distant metastasis (J Thorac Dis 2018;10:3595)
    • 80% are N0 at the time of diagnosis (versus 55% in nonmucinous adenocarcinoma)
    • 80% are M0 at the time of diagnosis (versus 55% in nonmucinous adenocarcinoma)
  • Larger size and higher T category at presentation
Diagnostic criteria
  • Based on histological and immunohistochemical features
  • Even if pathological results correspond to primary invasive mucinous adenocarcinoma of lung, colorectal adenocarcinoma must be ruled out by endoscopy and radiology
Radiology description
  • Consolidation with various appearance (Eur J Radiol 2015;84:993, Cancer Imaging 2019;19:47)
    • Solid lesion similar to other lung cancers
    • Mixed solid and gland glass opacity lesion similar to pneumonia
    • Air bronchogram is common
  • Often multifocal with multilobar involvement
  • FDG-PET often demonstrates relatively low accumulation to the lesion
Radiology images

Images hosted on other servers:
Computed tomography Computed tomography Computed tomography Computed tomography Computed tomography Computed tomography

Computed tomography

Prognostic factors
Case reports
Treatment
Gross description
Gross images

Contributed by Akira Yoshikawa, M.D. and Yale Rosen, M.D.
Invasive mucinous adenocarcinoma Invasive mucinous adenocarcinoma

Invasive mucinous adenocarcinoma

Invasive, diffuse

Invasive, diffuse

Lepidic growth pattern

Lepidic growth pattern

Microscopic (histologic) description
  • Goblet cells or GI tract type columnar cells
    • No criteria regarding percentage of cells with mucin but typically homogeneous and not admixed with nonmucinous glands
    • Abundant intracytoplasmic mucin
    • Basally oriented nuclei with minimal atypia
    • Adjacent alveolar lumens are often filled with mucin (not specific for invasive mucinous adenocarcinoma)
  • Tend to be well differentiated (J Thorac Dis 2018;10:3595)
    • Often predominantly lepidic growth with slight distortion / destruction of alveolar architecture
    • Admixed with minor papillary, acinar or micropapillary component
  • Spread through air space is common
Microscopic (histologic) images

Contributed by Akira Yoshikawa, M.D.

Intraalveolar mucin

Nodules with fibrosis

Tumor periphery

Diffuse spread

Acinar growth pattern


Admixed pneumocytes

Abundant apical mucin

Extracellular and apical mucin

HNF4α

TTF1 / Napsin A

Cytology description
Cytology images

Contributed by Takashi Hori, C.T. and Akira Yoshikawa, M.D.

Cluster of tumor cells

Gold mucin

Papillary cluster

Positive stains
Negative stains
Molecular / cytogenetics description
Sample pathology report
  • Lung, right upper lobe, resection:
    • Invasive mucinous adenocarcinoma (see synoptic report)
Differential diagnosis
  • Metastatic colorectal adenocarcinoma:
    • Endoscopic and radiologic examination critical
    • Usually multifocal
    • Tend to be more solid and dense
    • Proliferation of neoplastic columnar cells with abundant intracytoplasmic mucin
    • CDX2 and CK20 positive
  • Colloid adenocarcinoma (Hum Pathol 2015;46:836):
    • Marked mucin pool replacing normal parenchyma
    • Neoplastic epithelium floating in the mucin
    • Fragments of displaced alveolar walls
    • Minimal nuclear atypia
    • Fibrotic encapsulation in minor cases (formerly called cystadenocarcinoma)
Board review style question #1

This patient had multifocal pulmonary lesions. CK20 was positive. Which other marker substantiates the diagnosis and would likely be expressed?

  1. TTF1
  2. PAS
  3. Alcian blue
  4. EpCAM
  5. CDX2
Board review style answer #1
E. This is metastatic colorectal adenocarcinoma which usually expresses CDX2 and CK20.

Reference: Invasive mucinous adenocarcinoma

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Board review style question #2
Which of the following findings specifically corresponds to invasive mucinous adenocarcinoma of the lung compared with other sybtypes of lung adenocarcinoma?

  1. Abundant mucin in air spaces
  2. Abundant intracytoplasmic mucin
  3. TTF1 positive
  4. Napsin A positive
  5. p40 positive
Board review style answer #2
B. Abundant intracytoplasmic mucin

Reference: Invasive mucinous adenocarcinoma

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