Hyperenhancing paravertebral mass in an adolescent: A rare presentation of unicentric Castleman disease.

Castleman disease (CD) is a rare lymphoproliferative disorder with two main subtypes: unicentric Castleman disease (UCD) and multicentric Castleman disease (MCD). UCD typically presents as a single mass, often in the mediastinum or retroperitoneum. We present a case of a 16-year-old male with an incidentally identified paravertebral mass on chest radiograph. Subsequent chest CT imaging revealed a hyperenhancing soft tissue mass adjacent to the T10 vertebral body, extending laterally along the ribs. Ultrasound-guided biopsy followed by video-assisted surgical resection confirmed the diagnosis of UCD. Paravertebral involvement in CD is rare, with only a limited number of cases reported in the literature. The differential diagnosis for paravertebral masses includes nerve sheath tumors and lymphomas, making pathological confirmation essential. Imaging features, such as hyperenhancement on arterial-phase CT may help distinguish CD from other potential diagnoses on imaging. Complete surgical resection remains the treatment of choice for UCD. This case underscores the importance of imaging in identifying and diagnosing CD, particularly in unusual locations like the paravertebral region, and highlights the necessity of accurate differential diagnosis to guide appropriate management.