Beguiled by the gallium. Thymic rebound in an adult after chemotherapy for Hodgkin's disease.

Abstract

An 18-year-old woman was diagnosed as having Hodgkin's disease involving the mediastinal lymph nodes and lung parenchyma. A pretreatment gallium 67 scan showed increased uptake in the mediastinum. Chest radiograph and chest computed tomographic (CT) scans after chemotherapy demonstrated resolution of disease, and a repeated gallium scan was normal. Four months later, a surveillance gallium scan showed increased activity in the mediastinal and hilar regions with corresponding chest CT and magnetic resonance imaging (MRI) showing a retrosternal mass. Prior to committing the patient to aggressive treatment for presumed disease relapse, a biopsy of the mass was performed and a specimen showed normal thymus tissue. The patient has continued in remission without further therapy 3 years after her initial treatment, with subsequent normal gallium scans and a stable mass on CT and MRI. Thymic enlargement following chemotherapy can occur with Hodgkin's disease in young adults, and interpretation of imaging studies, including gallium scanning, must be made with this consideration in mind.