Follicular lymphoma grade IIIb, intrathoracic lymph nodes

This code signifies a specific type of non-Hodgkin lymphoma, follicular lymphoma, characterized by a higher grade (grade IIIb) indicating more aggressive cell proliferation. The disease is localized to the intrathoracic lymph nodes, meaning the lymph nodes within the chest cavity are affected.

Use this code when documentation confirms a diagnosis of follicular lymphoma, specifically identified as grade IIIb, and the primary site of involvement is the intrathoracic lymph nodes. This diagnosis is typically established through biopsy and histopathological examination, with the grade and location clearly specified in the pathology report or physician's notes.

• Ensure the grade of follicular lymphoma is explicitly documented as "IIIb" to differentiate from other grades.
• Verify the anatomical site of involvement is precisely "intrathoracic lymph nodes" and not other lymph node regions.
• Always sequence this code as the primary diagnosis when it represents the reason for the encounter or admission.