Diagnosis of the vasculitic syndromes is usually based on characteristic histologic or arteriographic findings in a patient who has clinically compatible features. The images provided in this atlas highlight some of the characteristic histologic and radiographic findings that may be seen in the vasculitic diseases. These images demonstrate the importance that tissue histology may have in securing the diagnosis of vasculitis, the utility of diagnostic imaging in the vasculitic diseases, and the improvements in the care of vasculitis patients that have resulted from radiologic innovations.
Tissue biopsies represent vital information in many patients with a suspected vasculitic syndrome, not only in confirming the presence of vasculitis and other characteristic histologic features, but also in ruling out other diseases that can have similar clinical presentations. The determination of where biopsies should be performed is based on the presence of clinical disease in an affected organ, the likelihood of a positive diagnostic yield from data contained in the published literature, and the risk of performing a biopsy in an affected site. Common sites where biopsies may be performed include the lung, kidney, and skin. Other sites such as sural nerve, brain, testicle, and gastrointestinal tissues may also demonstrate features of vasculitis and be appropriate locations for biopsy when clinically affected.
Surgical biopsies of radiographically abnormal pulmonary parenchyma have a diagnostic yield of 90% in patients with granulomatosis with polyangiitis (Wegener’s) and play an important role in ruling out infection or malignancy. The yield of lung biopsies is highly associated with amount of tissue that can be obtained, and transbronchial biopsies, while less invasive, have a yield of only 7%. Lung biopsies also play an important role in microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (Churg-Strauss), and any vasculitic disease where an immunosuppressed patient has pulmonary disease that is suspected to be an infection.
Kidney biopsy findings of a focal, segmental, crescentic, necrotizing glomerulonephritis with few to no immune complexes (pauci-immune glomerulonephritis) are characteristic in patients with granulomatosis with polyangiitis (Wegener’s), microscopic polyangiitis, or eosinophilic granulomatosis with polyangiitis (Churg-Strauss), who have active renal disease. These findings not only distinguish these entities from other causes of glomerulonephritis, but can also confirm the presence of active glomerulonephritis that requires treatment. As a result, renal biopsies can also be helpful to guide management decisions in these diseases when an established patient has worsening renal function and an inactive or equivocal urine sediment. Cryoglobulinemic vasculitis and IgA vasculitis (Henoch-Schönlein) are other vasculitides where renal involvement may occur and where biopsy may be important in diagnosis or prognosis.
Biopsies of the skin are commonly performed and are well tolerated. Because not all purpuric or ulcerative lesions are due to vasculitis, skin biopsy plays an important role to confirm the presence of vasculitis as the cause of the manifestation. Cutaneous vasculitis represents the most common vasculitic feature that affects people and can be seen in a broad spectrum of settings including infections, medications, malignancies, and connective tissue diseases. As a result, for systemic vasculitides that will require aggressive immunosuppressive treatment, a skin biopsy may not represent sufficient evidence to secure the diagnosis.
Diagnostic imaging represents a critical assessment tool in patients who are known or suspected to have a systemic vasculitic disease. Imaging contributes unique information about the patient that, when taken together with the history, physical examination, and laboratory determinations, can guide the differential diagnosis and the subsequent assessment or treatment plan. A diverse range of imaging techniques is used in the assessment of vasculitis including plain radiography, ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography, and catheter-directed dye arteriography. These procedures have specific utilities that can allow differing perspectives on the spectrum and severity of vasculitis.
For vasculitic diseases that involve the large- or medium-sized blood vessels, arteriography provides information regarding blood vessel stenoses or aneurysms that can support the diagnosis. Catheter-directed dye arteriography provides information on central blood pressure and offers the most precise detail regarding vessel lumen dimensions but carries risks related to dye exposure and the invasive nature of the procedure. Advancements in magnetic resonance (MR) and CT arteriography have brought about noninvasive options to view the lumen and vessel wall, thus enhancing the ability to perform serial studies for patient monitoring in large-vessel vasculitis. However, in patients suspected to have a medium-vessel vasculitis such as polyarteritis nodosa, catheter-directed dye arteriography should still be performed because MR and CT arteriograms do not currently have sufficient resolution to visualize arteries of this size.
Although vasculitis involving the small blood vessels cannot be directly visualized, diagnostic imaging plays an essential role in detecting tissue injury that occurs as result of blood vessel and tissue inflammation. In granulomatosis with polyangiitis (Wegener’s), 80% of patients may have pulmonary involvement during their disease course. Chest imaging should be obtained whenever active disease is suspected, because up to one-third of patients with radiographic abnormalities are asymptomatic. Pulmonary imaging is also important to detect complications of vasculitis therapy such as opportunistic pneumonias and medication-related pneumonitis.
Bilateral nodular infiltrates seen on computed tomography of the chest in a 40-year-old woman with granulomatosis with polyangiitis (Wegener’s).
Computed tomography of the chest in two patients with granulomatosis with polyangiitis (Wegener’s) demonstrating (A) single and (B) multiple cavitary lung lesions.
Bilateral ground-glass infiltrates due to alveolar hemorrhage from pulmonary capillaritis as seen in the same patient by (A) chest radiograph and (B) computed tomography. This manifestation can occur in granulomatosis with polyangiitis (Wegener’s) or microscopic polyangiitis.
Computed tomography of the chest demonstrating a dense infiltrate with air bronchograms involving a segment of the right upper lobe due to bacterial pneumonia in an immunosuppressed patient with granulomatosis with polyangiitis (Wegener’s). Collapse of the left upper lobe secondary to endobronchial stenosis from granulomatosis with polyangiitis (Wegener’s) also is seen on this image.
Computed tomography of the orbits in a patient with granulomatosis with polyangiitis (Wegener’s) who presented with right-eye proptosis. The image demonstrates inflammatory tissue extending from the ethmoid sinus through the lamina papyracea and filling the orbital space.
Computed tomography of the sinuses in two patients with granulomatosis with polyangiitis (Wegener’s). (A) Mucosal thickening of the bilateral maxillary sinuses and a perforation of the nasal septum. (B) Osteitis with obliteration of the left maxillary sinus in a patient with long-standing sinus disease.
Computed tomography of the chest demonstrating a large pericardial effusion in a patient with eosinophilic granulomatosis with polyangiitis (Churg-Strauss). Cardiac involvement is an important cause of morbidity and mortality in eosinophilic granulomatosis with polyangiitis and can include myocarditis, endocarditis, and pericarditis.
Arteriogram of a 40-year-old man with polyarteritis nodosa demonstrating microaneurysms in the hepatic circulation.
Arteriogram of a 19-year-old man with polyarteritis nodosa demonstrating multiple microaneurysms in the renal circulation. The patient presented with headache and severe hypertension that was due to medium-vessel vasculitis affecting the kidney.
Cerebral arteriogram demonstrating beading along branches of the internal carotid artery in a patient with primary central nervous system vasculitis.
Upper-extremity arteriogram demonstrating a long stenotic lesion of the axillary artery in a 75-year-old female with giant cell arteritis.
Magnetic resonance imaging demonstrating extensive aneurysmal disease of the thoracic aorta in an 80-year-old female. The patient had been diagnosed with biopsy-proven giant cell arteritis 10 years prior to presenting with this aneurysm.
Arteriogram of the aortic arch demonstrating complete occlusion of the left common carotid artery just after its origin from the aorta. This 20-year-old female presented with syncope and was subsequently diagnosed with Takayasu arteritis.
Arteriogram demonstrating stenosis of the abdominal aorta in a 25-year-old female with Takayasu arteritis.
Arteriogram of the hand demonstrating arterial skip lesions and vessel cutoffs in a patient with cryoglobulinemic vasculitis due to multiple myeloma.
Lung histology in granulomatosis with polyangiitis (Wegener’s). This lung biopsy shows areas of geographic necrosis with a border of histiocytes and giant cells. There is also vasculitis with neutrophils, lymphocytes, and giant cells infiltrating the wall of an artery.
Lung histology in microscopic polyangiitis. This lung biopsy demonstrates hemorrhage in the alveolar spaces due to capillaritis in a patient with microscopic polyangiitis. Similar findings can also be seen in granulomatosis with polyangiitis (Wegener’s) and less commonly in eosinophilic granulomatosis with polyangiitis (Churg-Strauss).
Kidney biopsy in granulomatosis with polyangiitis (Wegener’s). This renal biopsy shows a crescentic and necrotizing glomerulonephritis. These findings were focal and segmental with normal and scarred glomeruli also being found in the biopsy. By immunofluorescence and electron microscopy, no immune deposits were present, indicative of a pauci-immune glomerulonephritis. Similar findings can also be seen in microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis (Churg-Strauss).
Sural nerve biopsy in polyarteritis nodosa. This sural nerve biopsy was performed in a patient with polyarteritis nodosa, who had presented with a mononeuritis multiplex. Neutrophils are seen infiltrating all layers of this medium-sized vessel, which resulted in vessel occlusion and nerve infraction.
Temporal artery biopsy in giant cell arteritis. This temporal artery biopsy demonstrates a panmural infiltration of mononuclear cells and lymphocytes that are particularly seen in the media and adventitia. Scattered giant cells are also present.
Cutaneous vasculitis. This skin biopsy reveals two arterioles beneath the dermis with a neutrophilic inflammatory infiltrate in and around the vessel wall with leukocytoclasis (nuclear debris). While such features are diagnostic of vasculitis, they can be seen in a variety of settings and are not specific for any single disease.
Granulomatous primary central nervous system vasculitis. This brain biopsy demonstrates a medium-sized artery with granulomatous inflammation present within the vessel wall indicative of a granulomatous vasculitis. This patient presented with progressive headache, clinical and radiographic features of a stroke, and had arteriographic features consistent with vasculitis. Because no evidence of vasculitis could be found outside of the brain, this was consistent with granulomatous primary central nervous system vasculitis.