From Head to Toe: Granulomatosis with Polyangiitis

Abstract

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody-associated vasculitis. It is an uncommon multisystem disease involving predominantly small vessels and is characterized by granulomatous inflammation, pauci-immune necrotizing glomerulonephritis, and vasculitis. GPA can involve virtually any organ. Clinical manifestations are heterogeneous and can be classified as granulomatous (eg, ear, nose, and throat disease; lung nodules or masses; retro-orbital tumors; pachymeningitis) or vasculitic (eg, glomerulonephritis, alveolar hemorrhage, mononeuritis multiplex, scleritis). The diagnosis of GPA relies on a combination of clinical findings, imaging study results, laboratory test results, serologic markers, and histopathologic results. Radiology has a crucial role in the diagnosis and follow-up of patients with GPA. CT and MRI are the primary imaging modalities used to evaluate GPA manifestations, allowing the differentiation of GPA from other diseases that could simulate GPA. The authors review the main clinical, histopathologic, and imaging features of GPA to address the differential diagnosis in the affected organs and provide a panoramic picture of the protean manifestations of this infrequent disease. The heterogeneous manifestations of GPA pose a significant challenge in the diagnosis of this rare condition. By recognizing the common and unusual imaging findings, radiologists play an important role in the diagnosis and follow-up of patients with GPA and aid clinicians in the differentiation of disease activity versus disease-induced damage, which ultimately affects therapeutic decisions.

Orbital Muscle Enlargement: What if It’s Not Graves’ Disease?

“…CT can show diffuse inflammation with bone destruction. MR shows T1-and T2-weighted hypointense enhancing lesions [50]. Most importantly, imaging is not always specific for GPA.…”

Mucormycosis an added burden to Covid-19 Patients: An in-depth systematic review

“…The infection commonly develops from the paranasal sinuses, which lead to bone loss and eventually spreads to the orbit, eye, and brain. There may be unilateral facial oedema, proptosis, and a palatal or palpebral fistula that develops into necrosis [54] . Pulmonary mucormycosis is the second most widespread infections among different clinical presentations of mucormycosis.…”

Granulomatosis with polyangiitis: Common and uncommon presentations

“…These may be formed from the coalescence of smaller areas of diffuse haemorrhage into denser areas of haemorrhagic consolidation, which can be life threatening if not treated. A ‘tree‐in‐bud’ pattern or mosaic attenuation can be another manifestation when there is pulmonary arteriolar involvement 12 …”

“…10,11 Pulmonary nodules are often multiple and bilateral with variable sizes ranging from a few millimetres up to 10 cm, with a broncho-vascular or subpleural distribution. 12 They often have irregular and ill-defined margins (Fig. 1).…”

“…A 'tree-in-bud' pattern or mosaic attenuation can be another manifestation when there is pulmonary arteriolar involvement. 12 The halo sign, appearing as a rim of ground-glass opacity surrounding a consolidated nodule, is often due to haemorrhage around a nodule affected by GPA and is present in around 15% of patients (Fig. 5).…”