(A911) Castleman Disease Presenting as a Parapharyngeal Mass: The First Pediatric Case in the United States

Introduction: Castleman Disease is a rare lymphoproliferative disorder that presents with benign slow-growing masses in a unicentric or multicentric pattern. Unicentric disease is typically asymptomatic unless compressing surrounding structures. Masses can rarely present in the head and neck, typically in cervical lymph nodes. Only a very small number have been reported in the parapharyngeal space in adults. We present the first case in the U.S. of unicentric parapharyngeal Castleman Disease in a pediatric patient.

Methods: Case report

Results: A 13-year-old female was referred after a large parapharyngeal mass was seen during outside adenotonsillectomy. Surgery was aborted and a biopsy was taken, showing lymphocytes and fibrous tissue. She had hyponasal voice, biopsy site pain, and snoring. MRI displayed a 7.6cm parapharyngeal mass extending from skull base to tongue base, intimately associated with the carotid artery. Repeat biopsy resulted in similar histologic findings with brisk intraoperative bleeding.

Given rapid growth with inconclusive biopsies, we elected for resection. Due to the high vascularity and association with the carotid artery, endovascular coiling of the ascending pharyngeal artery was performed. The following day, ~90% of the lesion was resected transorally with endoscopic assistance. Intraoperative frozen section showed only lymphocytes. With no evidence of malignancy, a small amount was left for safety along the carotid at the skull base.

Pathology showed Castleman Disease, hyaline vascular variant. Imaging confirmed unicentric disease. Once tolerating liquids, the patient was discharged home; she remains under surveillance without further medical intervention or progression of her residual lesion to date.

Conclusions: We present an extremely rare case of Castleman Disease of the parapharyngeal space in a pediatric patient. As with other unicentric cases the patient was appropriately treated with surgical resection. Debulking is an adequate option when masses lie in close proximity to critical structures. Pre-operative embolization was a useful adjunct to successful resection.