Lung Cancer - Guidelines for Processing Specimens and Reporting Tumor Stage

Examination for T (tumor) stage

Description of the size and location of the primary tumor and the extent of invasion can be guided by the following examination process:

a) Describe the location (central, midzone, peripheral) and maximum dimension of the primary tumor.

b) If the tumor is centrally located, define grossly and microscopically its most proximal extent in relation to the bronchial margin of the specimen, and note whether the bronchus is a lobar or main bronchus. In a resected specimen, it is usually impossible to know where the mediastinal boundary is, and therefore the surgeon should be consulted in the assessment of suspected mediastinal, mediastinal pleura or pericardial involvement (any one of which would be defined as T3 disease). Similarly, the pathologist will not usually be able to determine the distance between the most proximal extent of tumor involvement and the carina in pneumonectomy specimens. Here again, the surgeon should be consulted if main stem bronchial involvement is present.

c) If the tumor is peripherally located, define grossly and microscopically its relation to visceral pleura and to parietal pleura/chest wall (when the latter is a part of the resection specimen). An elastic tissue stain is often helpful in defining the microscopic extent of tumor invasion when visceral pleura and/or parietal pleura/chest wall involvement is suspected.

Cancer Stage Established Through Identification of Size, Location, and Extent of Chest Wall Invasion by Primary Tumour

d) Note whether the primary tumor extends across a fissure into an adjacent lobe, as such tumors are considered to be T2 lesions.

e) Comment on the presence and extent of postobstructive pneumonia and/or atelectasis.

f) Examine the resection specimen carefully for additional tumor foci; note their presence and location in relation to the main tumor. Additional tumor foci of a different cell type should be independently assessed concerning T and N status. The presence of satellite tumor(s) within the primary tumor lobe of the lung should be classified as T4. Intrapulmonary ipsilateral metastasis in a lobe other than the one with the primary tumor should be classified as M1⁽⁴⁾. Bronchioloalveolar carcinoma, in contrast to other types of primary lung cancer, is known to have a tendency for multicentric growth¹⁰. In this instance, when multicentric growth is found within a resection specimen, the T status cannot be defined with certainty and therefore the designation Tx is appropriate.

g) Comment on the presence or absence of tumor involvement of the bronchial margin and other margins of resection, as appropriate, when the tumor directly extends beyond the lung.