Follicular bronchiolitis: clinical and pathologic findings in six patients

High-Resolution Computed Tomography of Nonfibrotic Interstitial Lung Disease

Nonfibrotic interstitial lung diseases include a heterogeneous group of conditions that can result in various patterns of lung involvement. When approaching the computed tomographic (CT) scan of a patient with a suspected or known interstitial lung disease, the use of the appropriate radiological terms and a systematic, structured approach to the interpretation of the imaging findings are essential to reach a confident diagnosis or to limit the list of differentials to few possibilities. The large number of conditions that cause nonfibrotic interstitial lung diseases prevents a thorough discussion of all these entities. Therefore, this article will focus on the most common chronic lung diseases that can cause these CT findings. A pattern-based approach is used, with a discussion of nodular pattern, consolidation, crazy paving, ground-glass opacities, septal thickening, and calcifications. The different clinical conditions will be described based on their predominant pattern, with particular attention to findings that can help in the differential diagnosis.

[Spontaneous remission of follicular bronchiolitis with nonspecific interstitial pneumonia: A case report and literature review]

A 41-year-old female patient was admitted in Department of Respiratory and Critical Care Medicine, Peking University Third Hospital because of having cough for a year. Multiple subpleural ground grass and solid nodules could be seen on her CT scan. Four months before admission, she began to experience dry mouth and eyes, blurred vision, finger joints pain, muscle pain and weakness in both lower limbs and weight loss. At the time of admission, the patient's vital signs were normal, no skin rash was seen, breath sounds in both lungs were clear, no rales or wheeze, no deformities in her hands, no redness, swelling, or tenderness in the joints. There was no edema in both lower limbs. Some lab examinations were performed. Tumor markers including squamous cell carcinoma (SCC) antigen, neuron-specific enolase (NSE), carcinoembryonic antigen (CEA), Cyfra21-1, pro-gastrin-releasing peptide (proGRP), carbohydrate antigen 125 (CA125) and carbohydrate antigen 199 (CA199) were all normal. The antinuclear antibody, rheumatoid factor, antineutrophil cytoplasmic antibody, anti-dsDNA antibody, anti-Sm antibody, anti-SSA/SSB antibody, anti-ribonucleoprotein (RNP) antibody, anti-Jo-1 antibody, anti-SCL-70 antibody and anti-ribosomal antibody were all negative. The blood IgG level was normal. The blood fungal β-1.3-D glucose, aspergillus galactomannan antigen, sputum bacterial and fungal culture, and sputum smear test for acid-fast staining were all negative. Lung function was normal. Bronchoscopy showed the airways and mucosa were normal. To clarify the diagnosis, she underwent thoracoscopic lung biopsy, the histopathology revealed follicular bronchiolitis (FB) with nonspecific interstitial pneumonia (NSIP). She did not receive any treatment and after 7 months, the lung opacities were spontaneously resolved. After 7 years of follow-up, the opacities in her lung did not relapse. To improve the understanding of FB, a literature research was performed with "follicular bronchiolitis" as the key word in Wanfang, PubMed and Ovid Database. The time interval was from January 2000 to December 2018. Relative articles were retrieved and clinical treatments and prognosis of FB were analyzed. Eighteen articles concerning FB with complete records were included in the literature review. A total of 51 adult patients with FB were reported, including 18 primary FB and 33 secondary FB, and autoimmune disease was the most common underlying cause. Forty-one (80.4%) patients were prescribed with corticosteroids and/or immunosuppressive agents, 6 (11.8%) patients were treated with anti-infective, 5 (9.8%) patients did not receive any treatment. The longest follow-up period was 107 months. Among the 5 patients without any treatment, 1 patients died of metastatic melanoma, the lung opacities were unchanged in 1 patient and getting severe in 3 patients. In conclusion, FB is a rare disease, the treatment and prognosis are controversial. Corticosteroid and immunosuppressive agents could be effective. This case report suggests the possibility of spontaneous remission of FB.

Follicular Bronchiolitis: Two Cases with Varying Clinical and Radiological Presentation

Follicular bronchiolitis (FB) is a rare bronchiolar disorder associated with hyperplasia of the bronchial-associated lymphoid tissue (BALT). It is characterized by the development of lymphoid follicles with germinal centers in the walls of small airways. It falls under the category of lymphoproliferative pulmonary diseases (LPDs) and commonly occurs in relation to connective tissue disease, immunodeficiency, infections, interstitial lung disease (ILD), and inflammatory airway diseases. Computerized tomography (CT) findings include centrilobular nodules with patchy ground glass infiltrate, tree-in-bud findings, and air trapping. It can very rarely present as diffuse cystic lung disease. We present two cases of FB. The first case is associated with Human Immunodeficiency Virus (HIV) infection and asthma with diffuse cystic changes on the CT. The second case is associated with reactive airway disease and gastroesophageal reflux disease (GERD) with the classic centrilobular nodules and ground glass opacities on the CT.

Small Airway Disease: A Step Closer to Etiology-Based Classification of Bronchiolitis

Three major histologic patterns of bronchiolitis: obliterative bronchiolitis, follicular bronchiolitis, and diffuse panbronchiolitis, are reviewed in detail. These distinct patterns of primary bronchiolar injury provide a useful starting point for formulating a differential diagnosis and considering possible causes. In support of the aim toward a cause-based classification system of small airway disease, a simple diagnostic algorithm is provided for further subclassification of the above 3 bronchiolitis patterns according to the major associated etiologic subgroups.

The Clinical Characteristics and Outcomes of Follicular Bronchiolitis in Chinese Adult Patients

Follicular bronchiolitis (FB) is a rare interstitial lung disease (ILD) and has been reported in diverse clinical contexts. Six FB patients demonstrated by surgical lung biopsy (SLB) were reviewed between 2009 and 2017 from Nanjing Drum Tower Hospital in China. The average age of subjects was 42 years old (range: 31-55 years). The clinical symptoms were very mild. The laboratory findings showed elevated Erythrocyte sedimentation rate (ESR) and serum globulin and anemia. Pulmonary function tests were normal in four cases. Five cases had underlying diseases, such as, Sjo¨gren's syndrome, multi-centric castlemans' disease, idiopathic pneumonia with autoimmune features and abscess. Five cases presented as interstitial lung disease (ILD) on chest imaging with centrilobular or peribronchiolar nodules, ground glass opacities, interlobular septal thickening, cysts and bronchiectasis. Isolated mass was in one patient. The histopathology suggested the changes of FB in all subjects. Prednisone and/or cyclophosphamide were used in four cases, one did the surgery and the other was clinically monitored. All cases were alive at the end of follow up. The adult patients of FB usually have mild symptoms, ILD and underlying diseases. The definite diagnosis needs SLB. The prognosis is depended on their underlying conditions.

Follicular bronchiolitis in an HIV-infected individual on combination antiretroviral therapy with low CD4+ cell count but sustained viral suppression

A 36-year-old Danish man, living in Asia, was diagnosed with Pneumocystis pneumonia (PCP) and HIV in 2013 (CD4+ count: 6 cells/µL; viral load: 518 000 copies/mL). He initiated combination antiretroviral therapy. Later that year, he was also diagnosed with granulomatosis with polyangiitis and was treated with prednisolone. Despite complete viral suppression and increasing CD4+ count (162 cells/µL), he was readmitted with PCP in April 2015. Subsequently, he returned to Denmark (CD4+ count: 80 cells/µL, viral suppression). Over the following months, he developed progressive dyspnoea. Lung function tests demonstrated severely reduced lung capacity with an obstructive pattern and a moderately reduced diffusion capacity. High resolution computer tomography revealed minor areas with tree-in-bud pattern and no signs of air trapping on expiratory views. Lung biopsy showed lymphocytic infiltration surrounding the bronchioles with sparing of the alveolar septa. He was diagnosed with follicular bronchiolitis. The patient spontaneously recovered along with an improvement of the immune system.

Follicular Bronchiolitis in a Nigerian Female Child: A Case Report and Review of the Literature

Small airways diseases are not uncommon in childhood. They account for about 28.4% of hospital admissions for lower respiratory tract infections in South West Nigeria, most of which are due to respiratory syncytial virus (RSV) infection. Noninfectious causes of small airways diseases, on the other hand, are poorly recognized and rarely feature in the differential diagnoses of chronic/recurrent lower respiratory tract disease in our environment. We present a case of follicular bronchiolitis in a 2.5-year-old Nigerian female who had left upper lobectomy on account of recurrent cough and progressive shortness of breath.

Follicular Bronchiolitis: A Literature Review

Follicular bronchiolitis (FB) also known as hyperplasia of the bronchial associated lymphoid tissue (BALT), or bronchiolar nodular lymphoid hyperplasia, is an entity characterized by the development of lymphoid follicles with germinal centers in the walls of small airways. FB is thought to be caused by antigenic stimulation of BALT, followed by a polyclonal lymphoid hyperplasia. It is currently classified as one of the reactive pulmonary lymphoid disorders in a group known as the lymphoproliferative pulmonary diseases (LPDs). FB is a pathological diagnosis that can be seen in several clinical settings, including connective tissue diseases, immunodeficiency states, autoimmune diseases, infections, obstructive airway diseases, as well as several types of interstitial lung diseases (ILDs). Its characteristics need to be carefully identified and differentiated from other closely related diseases in the group of LPDs due to significant differences in treatment and prognosis.

Lymphoproliferative lung disorders: a radiologic-pathologic overview. Part I: Reactive disorders

Lymphoid tissue is a normal component of the lung and manifests as intrapulmonary lymph nodes, bronchus-associated lymphoid tissue (BALT), peripheral lymphocytic aggregates, solitary lymphocytes, and phagocytic cells. Pulmonary lymphoid lesions are thought to develop as a consequence of anomalous stimulation and response of the bronchus-associated lymphoid tissue and manifests as a spectrum of lymphoproliferative disorders that may be reactive or neoplastic. Reactive disorders are polyclonal abnormalities and include nodular lymphoid hyperplasia, lymphocytic interstitial pneumonia, follicular bronchiolitis, angiofollicular hyperplasia, and enlarged intrapulmonary lymph nodes. Affected patients are often asymptomatic. Imaging findings include focal nodules, diffuse bilateral centrilobular nodules, and hilar or mediastinal masses.

A case of follicular bronchiolitis associated with asthma, eosinophilia, and increased immunoglobulin E

A 49-year-old woman, who had been diagnosed with asthma, showed a bilateral diffuse pattern of small centrilobular nodules on CT. Laboratory data revealed peripheral eosinophilia and a marked increase in total serum IgE levels. The nodules detected on CT were initially considered to be associated with bronchiolar infiltration of eosinophils. Pathological findings from thoracoscopy revealed infiltration of eosinophils into the airway lumen and walls, goblet cell hyperplasia, and thickening of the basement membrane in large bronchi, consistent with asthma. However, hyperplastic lymphoid follicles with reactive germinal centers were observed along the bronchioles. The follicles had no evidence of monoclonality suggested by immunohistological analysis, and no remarkable infiltrates of eosinophils, suggesting follicular bronchiolitis (FB). After treatment with prednisolone, the small diffuse nodules improved markedly, and peripheral eosinophilia and total serum IgE levels also decreased. To the best of our knowledge, this is the first documented case report of FB associated with asthma, eosinophilia, and elevated IgE with a definite pathophysiological diagnosis.

Pathology of small airways disease

CONTEXT

The term small airways disease encompasses a generally poorly understood group of lung diseases that may arise primarily within the small airways or secondarily from diseases primarily affecting the bronchi or lung parenchyma. Their histology may be confusing; however, because treatments and prognoses vary, correct pathologic diagnosis is important.

OBJECTIVE

To present a nonexhaustive review of the pathology of primary and secondary small airways diseases, including small airways disease related to tobacco; to various other exposures, including mineral dusts; to diseases involving other areas of the lung with secondary bronchiolar involvement; and to recently described bronchiolitic disorders.

DATA SOURCES

Current literature is reviewed.

CONCLUSIONS

Small airways diseases include a wide variety of diseases of which the pathologist must consider. Uncommon conditions such as diffuse idiopathic neuroendocrine cell hyperplasia and diffuse panbronchiolitis may show relatively specific diagnostic features histologically; however, most small airways diseases exhibit nonspecific histologic features. Conditions not considered primary pulmonary diseases, such as collagen vascular diseases, bone marrow transplantation, and inflammatory bowel disease, must also be considered in patients with small airways changes histologically. Clinical and radiologic correlation is important for obtaining the best possible diagnosis.

Update on nonneoplastic pulmonary lymphoproliferative disorders and related entities

CONTEXT

Recent discoveries have expanded the spectrum of nonneoplastic pulmonary lymphoproliferative disorders and have provided new insights into their pathogenesis and treatment.

OBJECTIVE

To review the thoracic manifestations of immunoglobulin (Ig) G4-related sclerosing disease and summarize current concepts and differential diagnosis of follicular bronchiolitis, lymphocytic interstitial pneumonitis, and nodular lymphoid hyperplasia.

DATA SOURCES

Data sources include recent and old articles, cases from the personal files of the author, and cases borrowed with permission from other authors.

CONCLUSIONS

Additional studies will be needed to further refine and add to observations in this evolving area of pulmonary pathology.

Follicular bronchiolitis: a rare cause of bronchiolitis obliterans syndrome after lung transplantation: a case report

This case report is the first confirmed case of follicular bronchiolitis (FB), a rare bronchiolar disorder characterized by peribronchiolar lymphoid follicles, in a series of over 400 lung transplantations performed in our center. It is to our knowledge, the first publication describing FB after lung transplantation (LTx), presenting as chronic allograft dysfunction or bronchiolitis obliterans syndrome (BOS).

Imaging of small airways disease and chronic obstructive pulmonary disease

CT is a useful tool for identification of small airways diseases, and it can be used to classify these entities into inflammatory and constrictive bronchiolitis. Inflammatory forms of bronchiolitis include cellular bronchiolitis (usually caused by infection or aspiration), respiratory bronchiolitis, panbronchiolitis, and follicular bronchiolitis. Constrictive bronchiolitis may be caused by previous infection, toxic inhalation, collagen vascular disease, or transplantation. CT also helps categorize chronic obstructive pulmonary disease into emphysema predominant and airway predominant forms.

Diffuse lymphoplasmacytic bronchiolitis in cartilage-hair hypoplasia

Three children with cartilage-hair hypoplasia presented with chronic obstructive symptoms and bronchiolar wall thickening on high-resolution computed tomography scanning. In all children, surgical lung biopsy demonstrated diffuse dilated lymphoplasmacytic bronchiolitis. The bronchiolar wall was infiltrated by a lymphocyte sheath with plasma cell differentiation and dispersed secondary follicles. Clarithromycin substantially improved respiratory symptoms and pulmonary function, allowing children to return home.

Follicular bronchiolitis in surgical lung biopsies: clinical implications in 12 patients

BACKGROUND

Follicular bronchiolitis is a histopathologic finding that occurs in diverse clinical contexts. The current study was conducted to characterize clinico-radiologic features, and assess outcomes associated with follicular bronchiolitis.

SUBJECTS AND METHODS

Twelve subjects with follicular bronchiolitis on lung biopsy were seen over a 9-year period, between 1996 and 2005. Medical records, biopsy and radiographic findings, and details of outcome at the time of last follow-up were recorded.

RESULTS

The study population included 4 men and 8 women; the median age at diagnosis was 54 years (range, 33-81 years). Four patients had underlying systemic diseases that included: 2 with common variable immunodeficiency, 1 Sjögren's syndrome and 1 undifferentiated connective tissue disease. The diagnosis was obtained by surgical lung biopsy in all cases. Follicular bronchiolitis was the major histologic pattern in 9 patients; organizing pneumonia, nonspecific interstitial pneumonia and usual interstitial pneumonia was seen in 1 patient each with follicular bronchiolitis being an associated secondary histopathologic component. Computed tomographic findings included reticular opacities, small nodules and ground-glass opacities. Clinical course was characterized by relative stability with partial response to immunosuppressive agents. During a median follow-up period of 47 months, only one death occurred--out of 9 patients where the outcome information was available--and was unrelated to lung disease.

CONCLUSIONS

The histologic lesion of follicular bronchiolitis may be seen as the predominant finding or a relatively minor feature in interstitial pneumonias. The clinical course and prognosis for most patients with follicular bronchiolitis is relatively good, and progressive lung disease is uncommon.

Follicular bronchiolitis, an unusual cause of haemoptysis in giant cell arteritis

The occurrence of follicular bronchiolitis (FB), lymphoid hyperplasia of the bronchus-associated lymphoid tissue, is reported in association with several systemic rheumatic diseases. However, the occurrence of FB in patients with giant cell arteritis (GCA) is not described. A 64-year-old man with long-standing GCA subsequently presented with haemoptysis. A mass in the lower lobe of the left lung was seen on chest x-ray and computed tomography. A wedge resection was performed, and histological examination revealed bronchiectasis, granulation tissue and hyperplasia of peribronchiolar lymphoid aggregates, consistent with FB. FB should be included in the differential diagnosis of haemoptysis in patients with systemic rheumatic diseases.