Pulmonary artery involvement due to Behçet's syndrome and Hughes Stovin syndrome: a comparative study

Hughes-Stovin syndrome (HSS) is a rare inflammatory condition defined as pulmonary artery aneurysms (PAA) associated with deep vein thrombosis. It is similar to vascular involvement of Behçet's syndrome (BS), but differs in the absence of typical skin-mucosal findings. Whether HSS is a distinct entity or a form fruste of BS is debated. We formally compared HSS cases retrieved from the literature to BS patients with PAI followed by a tertiary centre.

A systemic literature search using 'Hughes Stovin syndrome' as the key word covering the period between 2000 and 2023 revealed 58 (43 M/15 F) case reports (PROSPERO: CRD42023413537). We identified 74 (62M/12 F) BS patients with PAI followed up in a tertiary centre in Turkey from 2000 until 2020. We evaluated two cohorts head-to-head in terms of demographic and clinical features.

BS and HSS patients were found to be comparable with regard to several demographic, clinical and histopathological features. However, PAA were significantly more frequent and isolated pulmonary artery thrombosis (PAT) less common in HSS than that found in BS. Moreover, patients with HSS were more likely to be treated with anti-coagulants and vascular or surgical interventions, whereas less likely to receive immunosuppressive treatment.

Our study indicates that HSS is indeed an 'incomplete form of BS'. It can be considered as evidence supporting the notion that the vascular phenotype develops independently from skin-mucosa lesions and uveitis in BS. However, HSS has been described mainly focusing on aneurysms, overlooking the aspect of in-situ thrombosis.