Peroneus brevis tenosynovitis associated with hypertrophied peroneal tubercle: Comparative analysis of 2 cases and their etiologies.

Tenosynovitis of the peroneal brevis tendon is a relatively uncommon condition that can present with lateral foot pain, difficulty ambulating, and, in certain cases, the presence of a hypertrophied tubercle near the insertion site. Although many factors can predispose patients to peroneal tendon pathology-such as biomechanical abnormalities, inflammatory disorders, and connective tissue diseases-presentation can differ widely among individuals. This paper reports 2 distinct cases of peroneal brevis tenosynovitis with hypertrophied tubercles, illustrating how tubercle size, patient demographics, and underlying comorbidities can influence clinical decision-making and outcomes. The first case involves a middle-aged man with a notably large (10 mm) hypertrophied tubercle and minimal comorbidity. In contrast, the second case details an older woman with a smaller (5 mm) tubercle but significant comorbidities, including rheumatoid arthritis and a likely connective tissue disorder, whose weight-bearing pattern contributed more to her condition than the tubercle size itself. Advanced imaging, particularly MRI, played a pivotal role in delineating the underlying mechanisms of tendon pathology by characterizing tubercle size, tendon impingement, peritendinous inflammation, and associated joint or soft-tissue changes. These imaging findings directly influenced management decisions, guiding conservative vs surgical treatment strategies. These cases highlight the importance of individualized treatment approaches that account for both anatomical and systemic factors.