Lymphomatoid granulomatosis was designated as a distinct subgroup of pulmonary lymphproliferative disorders by the well known pulmonary pathologist Liebow. This category was based in large part on the histological features which are midway between Wegener granulomatosis and pulmonary lymphoma.
Etiology is unknown.
The angiocentric location of the granulomatous infiltration is critical to the diagnosis. The angiodestructive feature of the lesions frequently results in vascular compromise and focal infarction. The cellular infiltrates are composed of lymphocytes, histiocytes, plasma cells, and atypical lymphoid cells. These nodules and mass are usually ill-defined, shaggy and predominantly distributed in lower lungs. Half of cases demonstrate pleural based lesions probably due to infarction.