Question

In the Ann Arbor staging of Hodgkin lymphoma, a mediastinal mass is designated “bulky” (the X modifier) when its maximum width exceeds what proportion of the intrathoracic diameter on chest radiograph?

• A. Greater than one-third (>1/3) of the maximum intrathoracic diameter
• B. Greater than one-half (>1/2) of the maximum intrathoracic diameter
• C. Greater than one-quarter (>1/4) of the maximum intrathoracic diameter
• D. Greater than two-thirds (>2/3) of the maximum intrathoracic diameter

Hint:

The X modifier for a mediastinal mass uses a one-third radiographic ratio.

Answer 1

The Correct Option is A

Step 1: Recall the staging modifier. In Hodgkin lymphoma, the suffix “X” appended to the Ann Arbor stage denotes bulky disease, which carries prognostic and treatment significance (often requires combined chemo-radiotherapy).

Step 2: Apply the definition for a mediastinal mass. A mediastinal mass is called bulky when its maximal width is >1/3 (greater than one-third) of the maximum intrathoracic transverse diameter on an erect PA chest radiograph (at the level of T5-T6).

Step 3: Choose the answer. The threshold is >1/3 of the intrathoracic diameter (some references also use a single nodal mass ≥10 cm as bulky).

Step 4: Why the others are wrong - one-half, one-quarter and two-thirds are not the accepted radiographic cut-offs; the conventional and most widely tested value for mediastinal bulk is one-third.

Key fact: Bulky (X) mediastinal mass in Hodgkin lymphoma = width >1/3 of the intrathoracic diameter on chest X-ray.