Langerhans cell histiocytosis (LCH) is a rare neoplastic disorder characterized by abnormal proliferation of Langerhans cells affecting predominantly pediatric populations [1]. LCH encompasses a spectrum of disease with a range of presentations spanning many organ systems [1]. Thymic involvement (TI) is rarely described; however, we report a case of an 8-month-old female with a dyad of cutaneous and thymic LCH. Following initial subtle findings of thymic calcifications on staging non-contrast computed tomography (CT) scan, TI was clearly characterized via superficial chest and neck ultrasound. In this case, discovery of TI impacted the treatment plan. The purpose of this report is to highlight a potentially underdiagnosed manifestation of LCH in an 8-month-old infant and consider thymic sonography in staging evaluation for infants with LCH.