Benign lymphocytic angiitis and granulomatosis: a case report with evidence of an autoimmune etiology.

Benign lymphocytic angiitis and granulomatosis (BLAG) is characterized by dense benign-appearing infiltrates of mature lymphocytes, plasma cells, and histiocytes within the pulmonary parenchyma and vasculature. The disorder typically is restricted to the lungs and has a good prognosis. The authors report a patient with BLAG and involvement of lung, kidney, and prostate. This is the first report of prominent systemic distribution in this disease. Another unique feature of this case was the presence of serum antinuclear antibodies and evidence of immune complex deposition in both lung and kidney, suggesting an underlying autoimmune disorder. An association of this entity with lymphomatoid granulomatosis (LG) has been suggested, and the prominent genitourinary disease in this patient may be indicative of a transitional stage leading to LG. An autoimmune state may be the underlying stimulus for the development of BLAG and LG.