[Castleman tumor as a rare differential diagnosis of cervical space-occupying lesion]

Based on the case report of a 35-year-old patient presenting a Castleman tumor of the neck, we describe the diagnostic challenge of identifying this tumor entity. It is important to consider this type of tumor. Diagnostic imaging methods such as ultrasound and CT/MRI cannot identify the Castleman tumor due to the lack of tumor-specific signs but yield important information concerning exact tumor localization. Only surgical resection and conventional histology give a correct characterization of this tumor and possibly allow further additive treatment modalities.