The Transformation of Neck Unicentric Castleman's Disease to Follicular Dendritic Cell Sarcoma

A patient with a large neck mass underwent appropriate imaging, routine blood tests, and serological evaluations. The medical history revealed the patient had undergone a lymphadenectomy in the same region 8 years ago, and the pathological diagnosis was the hyaline-vascular subtype of unicentric Castleman's disease (UCD). The incisional biopsy and subsequent histopathological and immunohistochemical examination revealed the diagnosis of follicular dendritic cell sarcoma, consistent with the malignant transformation of UCD. UCD is uncommon and the malignant transformation of UCD is extremely rare in the head and neck region. Regional lymph node resection of one or more adjacent regions is the preferred treatment choice. Appropriate treatment procedures for UCD and regular follow-up are essential for a good prognosis. Laryngoscope, 134:4985-4987, 2024.