Granulomatosis with polyangiitis: Special focus on suggestive imaging findings in head and neck involvement

Abstract

Objective: Granulomatosis with polyangiitis (GPA) is a rare autoimmune disease with frequent upper respiratory tract involvement. Early diagnosis is crucial for early initiation of effective treatment, which improves outcome. Imaging plays an important role for confirming clinically suspected cases. The aim of our study is to reveal the frequencies of imaging findings previously defined as suggestive for GPA (i.e. osseous erosions or destructions, neoosteogenesis, subglottic stenosis) and to investigate frequency and characteristics of previously under-recognized nasopharyngeal involvement in GPA.
 Materials and Methods: We retrospectively examined paranasal, nasopharynx/neck, temporal CTs (n=51) and MRIs (n=14) of 48 patients with GPA. The evaluated imaging findings include mucosal ulcerations in nasal cavity, sinonasal and temporal opacifications/inflammatory signal changes, presence and locations of osseous erosions and neoosteogenesis, periantral soft tissue infiltration, septal perforation, presence and characteristics of nasopharyngeal involvement, and subglottic stenosis. Descriptive statistics were presented as mean ± SD; categorical variables were presented as count and percentage.
 Results: Forty patients (87%) had sinonasal and fourteen (29%) patients had tympanic cavity±mastoid opacifications. Three patients (23%) had signal and diffusion characteristics suggesting a sinonasal granulomatous inflammation. Mucosal ulcerations were detected in 32% of patients. Osseous erosions/destruction (40%) was common in disease onset and frequently affected mid-line sinonasal structures. Neoosteogenesis of paranasal sinuses (21%) was more common in follow-up studies and invariably affected maxillary sinuses. Septal perforation (6%), periantral infiltration (4%) and subglottic stenosis (10%) were relatively infrequent findings. Nasopharyngeal involvement (23%) was not infrequent; predominantly presented with wall thickening, ulcerations, low T2-weigted signal changes and restricted diffusion in MRI.
 Conclusion: Sinonasal osseous erosion/destruction is a relatively common and highly suggestive finding especially when co-existent with nasal mucosal ulcerations, neoosteogenesis and nasopharyngeal thickening in a suspected case. Nasopharyngeal involvement is not infrequent and imaging could overlap with other entities such as nasopharyngeal cancer, lymphoma or sarcoma.

Head and Neck Radiology in AAV

“…Neoosteogenesis is more frequently detected later in the course of the disease than in the disease onset. Accordingly, in the previous study enrolled in Hacettepe University Center of Vasculitis [5], neoosteogenesis were more frequent in the follow-up studies (66%) than in studies at onset (21%). In that study, osseous erosions were more common (40%) in CT scans at disease onset than neoosteogenesis.…”

“…The radiologic data comes generally from single cases and small series of nasopharyngeal involvement mimicking nasopharyngeal carcinoma [10][11][12]. In the study enrolled in Hacettepe University Center of Vasculitis [5], nasopharyngeal involvement is revealed as not an infrequent finding; detected in 23% of the patients, particularly at onset. Only one of these patients had nasopharyngeal disease during follow-up.…”

“…Temporal involvement typically presents as serous otitis media caused by obstruction of the eustachian tube due to direct extension of adjacent sinonasal disease [1]. Therefore, most of the patients with temporal involvement have coexistent sinonasal and/or nasopharyngeal disease [5]. CT manifestations are non-specific and includes opacifications of the middle ears and mastoid cells with thickening of bony septa [1,5].…”

“…Bony erosions/destructions result from avascular necrosis due to granulomatous inflammation and fibrinoid necrosis of small to medium arteries. It frequently initiates from the midline structures and proceeds laterally to involve turbinates and paranasal sinuses [4], although cases sparing midline osseous structures could also be detected [5].…”

“…Besides paranasal sinuses, mucosal thickening could also be detected in nasal cavity [3]. İrregular mucosal thickening with ulcerations and septa in nasal cavity is relatively suggestive for the diagnosis of GPA [5].…”