[Clinical Picture] Primary thyroid diffuse large B-cell lymphoma in a teenager

A 17-year-old boy with no personal or family history presented at St Louis Hospital in Paris in October, 2024 with a thyroid goitre that progressed over several weeks, rapidly causing dysphonia. A CT showed invasion of the thyroid gland by a lobulated structure infiltrating both lobes and the isthmus, measured at 75 × 46 mm (figure A). Biological investigations showed no abnormalities (normal complete blood count, and normal thyroid-stimulating hormone, thyroglobulin, and calcitonin levels). Thyroid fine needle aspiration disclosed the presence of large cells with dispersed chromatin (figure B).