Lymphomatoid granulomatosis (LYG) is a rare angiodestructive, lymphoproliferative disease with significant pulmonary involvement in the form of pulmonary angiitis and granulomatosis. LYG mimics Wegner’s granulomatosis (see p. 345), both in clinical and radiographic presentation.

The frequency of LYG occurrence is not known. Males are affected more than females at a 2:1 rate.

The true cause of LYG is not known. Recent evidence strongly suggests it is a distinct type of malignant lymphoma associated with immunosuppression. LYG is distinguished from Wegner’s granulomatosis by the involvement of B-cells.

Definitive diagnosis of LYG is based on the histologic triad of (1) granulomatosis, (2) polymorphic lymphocytic infiltrate, and (3) angiitis.

Symptoms include: