Case of the Week: March 4-March 11, 2011

CT image from the initial clinical staging of a woman with biopsy-proven 4.0 cm lung adenocarcinoma

Assume no enlarged lymph nodes, no distant metastases, apply recently revised 7th ed. of TNM classification for non-small cell lung cancer, what is clinical designation, stage of tumor?

(Click for a larger image.)



Case Details

Radiologic Findings Single unenhanced chest CT image (Fig. 1) (lung windows) through the upper lung zones shows a 4.0 cm polylobulated mass in the peripheral anterior segment of the left upper lobe. The mass is surrounded by aerated lung but does demonstrate irregular borders and a pleural tail.

Answer

Diagnosis: T2a N0 M0 Stage IB Adenocarcinoma of the Lung

Differential Diagnosis

Not Applicable

Discussion

In 2009, based on proposals from the International Association for the Study of Lung Cancer and the Lung Cancer Staging Project, the International Union Against Cancer (IASLC) and the American Joint Committee on Cancer (AJCC) released the revised 7th edition of the TNM classification for Non-Small Cell Lung Cancer. The revisions were based on a large database derived from 45 institutions and 20 nations under the auspices of the IASLC. Most of the revisions were directed towards the T (tumor) and M (metastases) descriptors and did not affect the N (nodal) descriptors.

T (tumor)-reflects the greatest dimension or size of the lesion as well as its location in the thorax relative to the airways and its degree of invasiveness with respect the pleura, chest wall, and mediastinum. Under the revised system, the T of the lesion is question is designated based on the following size criterion:

T1a
T1b
T2a
T2b
T3
≤2.0 cm
> 2.0 ≤ 3.0 cm
>3.0 ≤ 5.0 cm
>5 cm ≤ 7 cm 
>7 cm

The mere presence of a pleural tail does not indicate visceral pleural invasion. As a radiologist staging a patient, we are always obligated to down stage a patient not upstage the patient.

There are additional “T” criterion applied with respect to a given tumor’s location relative to the airway and its degree of invasiveness with respect to the chest wall, pleura, and mediastinal structures. These latter criteria are beyond the scope of today’s discussion. The reader is referred to the Selected Readings at the end of today’s case discussion to learn more.

As the lesion in our test case is >3 cm but ≤ 5 cm and surrounded by aerated lung, its clinical designation is T2a.

In the absence of nodal or metastatic disease, (i.e., N0; M0) under the revised system, this lesion’s clinical stage would be Stage IB

 

 
N0
N1
N2
N3
 
 
 
 
 
T1a
IA
IIA
IIIA
IIIB
T1b
IA
IIA
IIIA
IIIB
T2a
IB
IIA
IIIA
IIIB
T2b
IIA
IIB
IIIA
IIIB
T3
IIB
IIIA
IIIA
IIIB
T4
IIIA
IIIA
IIIB
IIIB
M1a
IV
IV
IV
IV
M1b
IV
IV
IV
IV

 

Selected Readings

  1. Diederich S. Lung Cancer Staging Update: The Revised TNM Classification. Cancer Imaging 2010; 10: Spec no A: S134-135.
  2. Klingerman S, Abbott G. A Radiologic Review of the New Classification for Lung Cancer. AJR 2010; 194(3): 562-573.
  3. Rami-Porta R, Crowley JJ, Goldstraw P. The Revised TNM Staging System for Lung Cancer. Ann Thorac Cardiovasc Surg 2009; 15(1): 4-9.
  4. www.iaslc.org

 

Correct answers by users

Radiology Medicine/Pulmonary
VCU Resident
  • Brian Deuell
  • Jonathan Ha
  • Laveena Chhatwani
    Others
  • Ali Asghar Aghajani AhmadiIran
  • Rashmi BalasubramanyaUnited States of America
  • Amol JagdaleIndia
  • Imran JindaniIndia
  • Robert PalmerUnited States of America
  • S RajeshIndia
  • S VelaUnited States of America
    VCU Department of Thoracic Imaging Virginia Commonwealth University VCU Medical Center