Bronchocentric injury in Wegener's granulomatosis: a report of five cases

Pulmonary pathology in vasculitis

Pulmonary involvement is frequent in vasculitis, particularly in ANCA-associated small vessel vasculitis. Laboratory and radiological data alone are often sufficient to confirm the clinical hypothesis, but sometimes the pathologist plays a crucial role in the differential diagnosis and the patient's management. In this review, the pathologic features of pulmonary vasculitis and the pathologist's role in this field are illustrated.

Granulomatous lung disease: an approach to the differential diagnosis

CONTEXT

Granulomas are among the most commonly encountered abnormalities in pulmonary pathology and often pose a diagnostic challenge. Although most pathologists are aware of the need to exclude an infection in this setting, there is less familiarity with the specific histologic features that aid in the differential diagnosis.

OBJECTIVE

To review the differential diagnosis, suggest a practical diagnostic approach, and emphasize major diagnostically useful histologic features. This review is aimed at surgical pathologists who encounter granulomas in lung specimens.

DATA SOURCES

Pertinent recent and classic peer-reviewed literature retrieved from PubMed (US National Library of Medicine) and primary material from the institutions of both authors.

CONCLUSIONS

Most granulomas in the lung are caused by mycobacterial or fungal infection. The diagnosis requires familiarity with the tissue reaction as well as with the morphologic features of the organisms, including appropriate interpretation of special stains. The major noninfectious causes of granulomatous lung disease are sarcoidosis, Wegener granulomatosis, hypersensitivity pneumonitis, hot tub lung, aspiration pneumonia, and talc granulomatosis.

Imaging of pulmonary vasculitis

The presence of pulmonary vasculitis can be suggested by a clinical presentation that includes diffuse pulmonary hemorrhage, acute glomerulonephritis, chronic refractory sinusitis or rhinorrhea, imaging findings of nodules or cavities, mononeuritis multiplex, multisystemic disease, and palpable purpura. Serologic tests, including the use of cytoplasmic antineutrophil cytoplasmic antibody (ANCA) and perinuclear ANCA, are performed for the differential diagnosis of the diseases. A positive cytoplasmic ANCA test result is specific enough to make a diagnosis of ANCA-associated granulomatous vasculitis if the clinical features are typical. Perinuclear ANCA positivity raises the possibility of Churg-Strauss syndrome or microscopic polyangiitis. Imaging findings of pulmonary vasculitis are diverse and often poorly specific. The use of a pattern-based approach to the imaging findings may help narrow the differential diagnosis of various pulmonary vasculitides. Integration of clinical, laboratory, and imaging findings is mandatory for making a reasonably specific diagnosis.

Vasculitis

Vasculitic syndromes involving the lung present a unique challenge for pathologists because of the histologic overlap with other disorders and the clinical implications of the diagnosis in regard to clinical management. This article reviews the more common vasculitic syndromes involving the lung, concentrating primarily on Wegener granulomatosis, Churg-Strauss syndrome, necrotizing sarcoid, microscopic polyangiitis, and diffuse alveolar hemorrhage syndromes. The article focuses on a review of the recent literature, diagnostic approach, and differential diagnosis.

Common diagnostic challenges in the pathology of nonneoplastic lung diseases: a case-based review

We use a case-based format to review 4 relatively common, diagnostic challenges in surgical pathology of nonneoplastic lung diseases. All cases are linked to virtual slides so that the reader can participate in a manner that simulates the breakout session held at the 2008 New Frontiers in Pathology course at the University of Michigan, from which, this material was excerpted. Brief clinical histories and a summary of radiologic findings are followed by a description of the pertinent histologic findings and a concise topic review, intended to focus on practical diagnostic considerations. Our goal is that readers gain a greater understanding of those features most helpful in recognizing usual interstitial pneumonia, Langerhans cell histiocytosis, aspiration pneumonia, and Wegener granulomatosis.

Pathological diagnosis of granulomatous lung disease: a review

Granulomas in the lung are common diagnostic problems encountered by pathologists. They occur in a wide range of pulmonary conditions, ranging from common entities to uncommon ones and including both infections and non-infectious diseases. This review summarizes the main histological features that help distinguish various granulomatous lung diseases. It concentrates on the most important and common entities that may be encountered and emphasizes helpful features in the differential diagnosis.

Bronchocentric granulomatosis associated with influenza-A virus infection

Bronchocentric granulomatosis is an unusual pathologic entity that is characterized by a necrotizing granulomatous inflammation surrounding the airways. The diagnosis is usually made retrospectively, after histopathologic examination of an open-lung biopsy or resection of a pulmonary lesion. Although the aetiology has not been fully elucidated, the current pathogenetic mechanism is considered to be an immunologic reaction against endobronchial antigens, since most patients exhibit signs of bronchial asthma, eosinophilia and allergic bronchopulmonary aspergillosis. However, non-asthmatic patients may develop bronchocentric granulomatosis without signs for endobronchial fungal infections, but probably as a consequence of other pulmonary infections. An 80-year-old female patient presented with high fever and bilateral pulmonary infiltrates and nodules. After extensive investigations and open-lung biopsy, the diagnosis bronchocentric granulomatosis was established that was possibly associated with an influenza-A virus infection. Treatment consisted of immunosuppressive drugs (prednisone and cyclophosphamide), which led to complete clinical and radiological recovery.

Antineutrophil cytoplasmic autoantibody in the absence of Wegener's granulomatosis or microscopic polyangiitis: implications for the surgical pathologist

Antineutrophil cytoplasmic antibodies (ANCA) are useful serologic markers for the diagnosis and management of patients with Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA). However, problems in diagnosis and classification may occur when patients with other disorders develop ANCA. A 7-year review (1993-1999) disclosed 247 patients whose sera tested positively for ANCA by an indirect immunofluorescence method: 166 patients for cytoplasmic-ANCA (C-ANCA) and 81 patients for perinuclear-ANCA (P-ANCA) Twenty-seven patients had active pulmonary disease and underwent open-lung biopsy or transbronchial biopsy. Eight patients (30%) had a disease other than WG or MPA, and their clinical, pathological, and serological findings were reviewed. The patients, all women, ranged in age from 28 to 77 years (median, 37 y). Dyspnea (n = 6), cough (n = 6), chest pain (n = 2), and/or hemoptysis (n = 2) were present. The duration of symptoms lasted from 3 weeks to 6 years (median, 6 mo). ANCA titers were C-ANCA (n = 4; range, 1:40-1280) or P-ANCA (n = 4; range, 1:40-640). The lung biopsies disclosed nonspecific interstitial pneumonia (n = 4), bronchiolitis obliterans organizing pneumonia (n = 1), diffuse alveolar damage (n = 1), organizing diffuse alveolar hemorrhage without capillaritis (n = 1), and necrotic granuloma (n = 1). No cases showed characteristic histology for WG or MPA. The final diagnoses were various connective tissue disorders (n = 5), chronic hypersensitivity pneumonia (n = 1), postinfectious bronchitis/bronchiectasis (n = 1), and ulcerative colitis-related lung disease (n = 1). Surgical pathologists should be aware that significantly elevated ANCA titers may be associated with diverse forms of pulmonary disease. ANCA positivity alone, in the absence of appropriate clinical or pathologic findings, should not be used to substantiate a diagnosis of WG or MPA.

Bronchocentric granulomatosis: computed tomographic findings in five patients

AIM

The aim of this study was to assess the CT manifestations of bronchocentric granulomatosis.

SUBJECTS AND METHODS

The CT results of five patients with bronchocentric granulomatosis were retrospectively analysed. The patients ranged from 20 to 72 years of age and included three men and two women. The diagnosis of bronchocentric granulomatosis was made at lobectomy (n = 2), open lung biopsy (n = 2), and transbronchial biopsy (n = 1). Only one of the five patients had asthma.

RESULTS

The main findings consisted of a spiculated mass lesion (n = 3) or lobar consolidation with associated mild volume loss (n = 2). One of the two patients with consolidation had extensive mucoid impaction. The abnormalities involved predominantly an upper lobe in four patients and a lower lobe in one patient. In the four resected specimens, the macroscopic pathological appearance was consolidation (n = 2) and mass lesion (n = 2). Microscopically, the typical histology of airway-centred necrotizing granulomata was present in all cases. Aspergillus hyphae were identified in two cases. Nocardia sp. was cultured from the biopsy specimen in one case.

CONCLUSION

The CT manifestations of bronchocentric granulomatosis consist of a focal mass or lobar consolidation with atelectasis. These reflect the presence of granuloma formation with or without associated bronchial obstruction.

Tracheal involvement in Wegener's granulomatosis: evaluation using spiral CT

OBJECTIVE

To describe the computed tomography (CT) appearances of tracheal stenosis in Wegener's granulomatosis (WG) and to assess the additional value of reformatted images.

PATIENTS AND METHODS

Ten patients with tracheal involvement by WG were assessed with spiral CT and both coronal and three-dimensional surface shaded images were generated. Fibreoptic bronchoscopy was also performed in all patients.

RESULTS

Ninety per cent of lesions were situated in the subglottic region. In all cases there was circumferential mucosal thickening, in nine cases extending over a relatively short distance (mean 2.4 cm). The degree of narrowing of the axial luminal diameter ranged from 23% to 100%. In three patients there was contiguous involvement of the vocal cords evident on CT, two further cases with mild vocal cord inflammation were identified bronchoscopically. Other CT findings included mucosal irregularity and ulceration (50%), and involvement of the tracheal cartilages (20%).

CONCLUSION

Wegener's granulomatosis may involve the trachea with resultant stenosis. Spiral CT is an easily performed, non-invasive technique which provides accurate assessment of tracheal lesions and is complementary to bronchoscopy. The main additional advantage of coronal reformatted images was our added confidence in defining the upper and lower limits of lesions and in the evaluation of vocal cord involvement.

Treated Wegener's granulomatosis: distinctive pathological findings in the lungs of 20 patients and what they tell us about the natural history of the disease

Patients with an established diagnosis of Wegener's granulomatosis (WG) sometimes undergo lung biopsy when the disease does not behave in the expected manner. Treatment affects the tissue reaction. The microscopic recognition of partially treated disease is important, as the absence of expected lesions may lead to nonspecific diagnoses and inappropriate management. The appearance of treated disease over time may offer insight into its histogenesis and natural history. We correlated clinical features and pulmonary histology in 20 patients with WG after they had been treated with corticosteroids or cyclophosphamide or both. All patients had inflammatory or fibrotic pulmonary disease resulting from WG, but only 4 (20%) had macronodular necrosis typical of WG. Serum antineutrophil cytoplasmic antibody (ANCA) was elevated in all patients in whom it was measured. We divided the pathological findings into (1) vasculitis, (2) extravascular necrosis, (3) bronchiolitis, and (4) other lesions, and further divided them into (a) diagnostic for active disease, (b) suspicious for active disease, (c) suspicious for healing disease, (d) suspicious for residual disease, and (e) possible disease. Diagnostic or suspicious vascular lesions occurred in 15 patients (75%) and included granulomatous vasculitis, capillaritis or suspicious capillaritis, and neutrophilic vasculitis. Diagnostic or suspicious extravascular lesions occurred in 12 patients (60%) and included palisading granuloma, microabscess, macronodular pathergic necrosis, giant cell nodules, and micronodular scars. The giant cell nodules and nodular scars were an unusual healing pattern of palisading granulomas. Diagnostic bronchiolar lesions occurred in 1 patient (6%) and suspicious lesions in 13 patients (65%), including three novel patterns of bronchiolitis fibrosa (BF): (1) BF with giant cells, (2) BF with hemosiderin, and (3) BF with micronodular scars. Other features related to WG included diffuse alveolar damage, peculiar alveolar fibrin, interstitial fibrosis, pneumonitis resembling usual interstitial pneumonitis, and lipoid pneumonia. Classic necrotic nodules and vasculitis of WG should not be anticipated after therapy, but the diagnosis of pulmonary WG after treatment may be made if the effects of treatment on histology are considered. Changes in anticipated histology are found after therapy as short as 6 days. The histology typically has muted features. BF develops in most patients and may reflect a salutary effect of therapy. Palisading granuloma may convert to giant cell nodule or micronodular scar. Interstitial fibrosis is common, and pneumonitis resembling usual interstitial pneumonitis can develop. If only healing or residual disease is encountered, one should search further clinically and pathologically for active disease. Dampened inflammatory lesions represent smoldering disease that presumably needs additional therapy. Scarring presumably represents successfully treated but permanent disease.

Bronchiolitis obliterans-organizing pneumonia (BOOP)-like variant of Wegener's granulomatosis. A clinicopathologic study of 16 cases

The classic histologic features of Wegener's granulomatosis (WG) in lung include necrotizing granulomatous inflammation and necrotizing vasculitis. Recently, several histologic variants have been recognized, including cases characterized by bronchocentric inflammation, a marked eosinophil infiltrate, alveolar hemorrhage, and capillaritis or interstitial fibrosis. We report 16 cases of another variant in which bronchiolitis obliterans-organizing pneumonia (BOOP)-like fibrosis represents the main histologic finding. The extensive geographic necrosis characteristic of Wegener's granulomatosis was absent in all cases, although small suppurative granulomas, minute foci of bland necrosis, and microabscesses were common. All cases showed the typical necrotizing vasculitis of Wegener's granulomatosis. Other frequent findings included darkly staining multinucleated giant cells, prominent acute inflammation, aggregates of epithelioid histiocytes, hemosiderin-filled macrophages, and areas of nonspecific parenchymal fibrosis. The clinical and radiographic features of this variant of Wegener's granulomatosis appear to be indistinguishable from the classic type. Pathologists need to be aware that Wegener's granulomatosis can occasionally manifest histologic changes suggestive of BOOP. The diagnosis will not be overlooked if additional features, especially vasculitis, suppurative granulomas, tiny necrotic zones, microabscesses, and multinucleated giant cells, are appreciated.

Computed tomography of the lung in Wegener's granulomatosis

Computed tomography of the thorax was performed in 30 patients with Wegener's granulomatosis to define the anatomical basis of pulmonary involvement. A wide variety of parenchymal and bronchial abnormalities was demonstrated in addition to the cavitary nodules commonly described. The high incidence (40%) of bronchial abnormalities in these patients may suggest that bronchocentric injury is more important in the pathogenesis of lung involvement in this disease than has previously been considered. Serial scans in individual patients showed broad correlation between the extent of the pulmonary abnormalities and the clinical and immunological markers of disease activity.