Disease Response to Pazopanib in Follicular Dendritic Cell Sarcoma.

Follicular dendritic cell sarcoma (FDCS) is a rare sarcoma, which commonly presents as a slow-growing, painless mass. There are only a few hundred reported FDCS cases, and the role for adjuvant chemo- or radiation therapy has not been established. Choosing an appropriate therapy in disseminated disease can therefore be challenging. A 26-year-old patient with FDCS was admitted with dyspnea, fever, and night sweats. He was found to have a large right hemothorax with compressive atelectasis on initial imaging. CT of the chest revealed multiple bilateral lung and pleural nodules with associated bilateral hilar adenopathy, a hypodense mass within the right hemithorax, and necrotic right external iliac and inguinal nodes. Inguinal node biopsy diagnosed FDCS. The patient was initially treated with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. Gemcitabine/Taxotere was given as second-line therapy and pembrolizumab as third-line therapy, with continued disease progression after 2 cycles of both regimens. The patient was switched to fourth-line therapy with pazopanib and had a partial response for 9 months. This case illustrates a successful FDCS treatment with pazopanib. Due to the rarity of FDCS, where large studies comparing treatment approaches are not available, recommendations for optimal treatment are not well defined. This case is in support of growing evidence suggesting that FDCS responds to systemic therapies that are used for soft tissue sarcoma, such as pazopanib.