Pulmonary lymphoid hyperplasia

As noted above, LIP is part of a spectrum of pulmonary lymphoid proliferations, ranging from follicular bronchitis-bronchiolitis to low-grade malignant lymphoma, patterns which may be difficult to distinguish from each other (5). When reactive lymphoid nodules are centered in a lymphatic distribution about airways, vessels, and interlobular septa, the disease is termed follicular bronchitis/ bronchiolitis [or pulmonary lymphoid hyperplasia (PLH)] in the pediatric AIDS literature) (60). As the disease becomes more florid and the reactive lymphoid infiltrate extends into the lung interstitium, then the process is termed LIP (3). 

Kradin RL, Young RH, Kradin LA, et al. Immimohlastic lymphoma arising in chronic lymphoid hyperplasia of the pulmonary interstitium. Cancer 1982 50(7) 1339 1343. 

---