Follicular lymphoma grade IIIa, intrathoracic lymph nodes

This code signifies a specific type of non-Hodgkin lymphoma, follicular lymphoma, characterized by a grade IIIa cellular morphology. The disease is located within the intrathoracic lymph nodes, meaning lymph nodes found inside the chest cavity. This grade indicates a more aggressive form of follicular lymphoma compared to grades I and II.

Use this code when documentation confirms a diagnosis of follicular lymphoma, specifically graded as IIIa, and the primary site of involvement is identified as intrathoracic lymph nodes. Supporting documentation would include pathology reports detailing the follicular lymphoma grade and imaging or biopsy reports confirming the intrathoracic location.

• Ensure the pathology report explicitly states "grade IIIa" for follicular lymphoma; do not assume based on other clinical factors.
• Verify the anatomical site is specifically "intrathoracic lymph nodes" and not other extranodal or abdominal sites.
• This code requires confirmation of both the specific histological grade and the precise anatomical location.