Langerhans cell histiocytosis involving only the thymus in an adult: A case report

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology. LCH involving the thymus is mainly seen in pediatric patients and is extremely rare in adults. In this report, we describe a rare case of LCH originating from the thymus in an adult. CASE SUMMARY: A 56-year-old man was admitted in April 2022 with complaints of intermittent dizziness since 2020, which had worsened in the previous 10 d. The physical chest examination was negative, and there was a history of hypertension for > 2 years. Chest computed tomography showed a nodular soft tissue density shadow in the anterior mediastinum measuring approximately 13 mm × 9 mm × 8 mm. Postoperative pathological findings confirmed the diagnosis of LCH. CONCLUSION: It is challenging to differentiate LCH involving the thymus from thymoma in imaging features. Pathological biopsy remains the gold standard when an anterior mediastinal occupying lesion is found.