Mediastinal (thymic) large B-cell lymphoma, unspecified site

This code identifies a specific type of aggressive non-Hodgkin lymphoma originating in the mediastinum, characterized by large B-cells and often associated with the thymus. It represents a primary mediastinal large B-cell lymphoma (PMBCL) where the precise anatomical site within the mediastinum is not specified in the medical record.

Use this code when documentation confirms a diagnosis of mediastinal large B-cell lymphoma, and the specific subsite (e.g., anterior mediastinum) is not detailed. This diagnosis is typically established through biopsy and immunohistochemical staining. It is appropriate when the physician explicitly states "mediastinal (thymic) large B-cell lymphoma, unspecified site."

• Ensure the pathology report confirms "large B-cell lymphoma" and specifies its mediastinal origin.
• Do not use this code if a more specific mediastinal site (e.g., anterior mediastinum) is documented; instead, use the appropriate subsite code.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter or hospitalization.