Background: Behçet’s disease (BD) is a multisystemic vasculitis characterized by inflammation of vessels of all calibers, with vascular involvement representing one of its most severe manifestations. Among arterial complications, pulmonary artery aneurysm (PAA) is the most distinctive and life-threatening lesion. Despite its rarity, PAA contributes disproportionately to morbidity and mortality in BD.

Objectives: This systematic review aimed to determine the prevalence, clinical spectrum, and outcomes of PAA in BD, and to contextualize Hughes–Stovin syndrome (HSS) as a related entity within the same vasculitic continuum.

Methods: Following PRISMA 2020 guidelines, a comprehensive search was conducted in PubMed/MEDLINE up to October 2025 using terms related to Behçet’s disease, pulmonary artery aneurysm, and Hughes–Stovin syndrome. Denominator-defined cohorts, descriptive pulmonary BD series, and HSS compilations were included. Data on study design, sample size, imaging method, prevalence, and mortality were extracted and summarized descriptively.

Results: Sixty-two publications were identified, of which fourteen met the inclusion criteria. Two denominator-based studies provided prevalence estimates between 0.16% and 1.1%, while several radiologic and clinical series confirmed PAA as the predominant pulmonary vascular manifestation of BD. Mortality historically approached 50% in early series but has declined to approximately 25–30% with modern immunosuppressive and biologic therapies. PAA occurs mainly in young men and is most frequently reported in Turkey and the Middle East, paralleling the geographic distribution of BD. HSS remains exceedingly rare, with fewer than 60 cases documented worldwide, and is now regarded as an incomplete or monosymptomatic form of BD.

Conclusions: Pulmonary artery aneurysm is an uncommon but pathognomonic feature of Behçet’s disease, affecting roughly 1% of patients and associated with high but improving mortality. Advances in imaging and immunosuppressive therapy have enhanced detection and survival. The close overlap between HSS and BD supports their inclusion within a shared vasculitic spectrum. Multicenter registries and standardized imaging criteria are needed to clarify regional disparities and long-term outcomes.