Follicular bronchiolitis

Cellular bronchiolitis Follicular bronchiolitis Diffuse panbronchiolitis Respiratory bronchiolitis... 

Sjogren syndrome (SS) is characterized by infiltration of CD4-positive lymphocytes into different organs, most notably the lacrimal and salivary glands. In the lung, the disease manifests as a prominent lymphoreticular infiltration in the tracheobronchial tree with follicular bronchiolitis, atrophy of glands, and fibrosis... 

Yousem SA, Colby TV, Carrington CB. Follicular bronchitis/bronchiolitis. Hum Pathol 1985 16 700-706. 

BALT in normal man is sparse, but a striking reactive lymphoid proliferation can occur in disease. These hyperplastic changes can differ in extent and location within the lung. This is the case in reactive lesions such as follicular bronchiolitis, lymphocytic interstitial pneumonia (LIP), and nodular lymphoid hyperplasia (NLH). 

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). 

Table 2 Differential Diagnosis of Nodular Lymphoid Hyperplasia (NLH), Lymphocytic Interstitial Pneumonia (LIP), Follicular Bronchiolitis (FB), and Extranodal Marginal Zone Lymphoma (Maltoma)... 

Follicular bronchiolitis is usually seen in adults, although it may also be seen in children (6,81). Patients typically have progressive dyspnea, cough and fever some may even present with recurrent pneumonia or weight loss (81). In cases where rheumatoid arthritis is the underlying cause, rheumatoid factor is often seen at very high titers (1 640 to 1 2560). 

The absence of a mass by chest X-ray helps distinguish follicular hyperplasia from NLH (Table 2). The separation between follicular bronchitis/bronchiolitis. 

Figure 5 See color insert.) Follicular bronchitis/bronchiolitis. The low magnification view, left panel, shows the peribronchiolar location of lymphoid aggregates in this condition. The right panel shows a reactive follicle center in one of the lymphoid aggregates.

Romero S, Barroso E, Gil J, et al. Follicular bronchiolitis clinical and pathologic findings in six patients. Lung 2003 181 309-319. 

Masuda T, Ishikawa Y, Akasaka Y, et al. Follicular bronchiolitis (FBB) associated with Legionella pneumophiha infection. Pediatr Pathol Mol Med 2002 21 517-524. 

Howling SJ, Hansell DM, Wells AU, et al. Follicular bronchiolitis thin-section CT and histologic findings. Radiology 1999 212(3) 637-642. 

Reittner P, Fotter R, Lindbichler F, et al. HRCT features in a 5-year-old child with follicular bronchiolitis. Pediatr Radiol 1997 27(ll) 877-879. 

Glandular and extra-glandular lymphocytic infiltration of the lung finds expression in a continuum from benign to malignant disease (from follicular bronchiolitis to LIP to lymphoma) (1,2). Airway involvement and ILD are the most frequent respiratory manifestations (Table 1). Lung involvement tends to be more frequent and severe in secondary than in primary SjS (193,194), with many of the lung abnormalities in secondary SjS ascribable to the associated CTD. 

OP (6,205,208) and, rarely DAD (208). Follicular bronchiolitis (Fig. 6) is frequently associated with NSIP as a major or minor lesion (6,181). Amyloid can be associated with LIP or lymphoma. Well-formed granulomas are also described (6,204). 

Figure 6 Follicular bronchiolitis observed as an associated lesion in a patient with primary Sjogren s syndrome and a pattern of nonspecific interstitial pneumonia. The lumen is narrowed by an extensive peribronchiolar lymphocytic infiltrate. HES lOOx.

SLE showed a major pattern of UIP for one and follicular bronchiolitis with minor NSIP areas for the other (6). In contrast to the other CTDs, the place of NSIP in SLE has not been yet definitely settled (4,6). LIP has been documented in SLE, but whether or not it was simply due to associated SjS is unknown (303-305). Isolated observations of OP have also been published (306-308). 

Vasculitis of recurrent laryngeal nerve Bronchiectasis Bronchiolitis obliterans Follicular bronchiolitis Diffuse panbronchiolitis Pleural disease... 

Other forms of airways disorders have also been described. Follicular bronchiolitis is a form of airways inflammation in which airways are obstructed by external compression of the bronchioles, rather than by direct luminal occlusion. A lymphocytic and plasma cell infiltrate surround the airway with germinal centers present within lymphoid follicles. Follicular bronchiohtis also has been described in Sjogren s syndrome, immunodeficiency syndromes, hypersensitivity-type reactions, and some chronic infections (14,15). 

Familial forms of follicular bronchiolitis Immunodeficiency Lysinuric protein intolerance Ataxia-T elangiectasia IgA nephropathy... 

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