Recurrent Malignant Schwannoma of the Parapharyngeal Space in Neurofibromatosis Type 1

Abstract

Malignant schwannoma is an aggressive tumor that carries a poor prognosis despite wide excision, chemotherapy, and radiotherapy. Malignant schwannoma of the parapharyngeal space is an uncommon finding; to our knowledge, only four cases have been described in the literature during the past 30 years, and only one of them involved a patient who had clinical evidence of neurofibromatosis type 1. In this article, we describe a new case of malignant schwannoma of the parapharyngeal space in a patient who had clinical evidence of neurofibromatosis type 1. Following resection of the tumor and a total parotidectomy, the diagnosis was made on the basis of histology and immunohistochemistry. The patient underwent postoperative chemotherapy with carboplatin and UP16. However, 5 months following surgery, the tumor recurred and metastasized. The patient was then placed on a different polychemotherapeutic regimen, which was made up of 3 g/m2 of ifosfamide, 1.5 mg/m2 of vincristine, and 1.5 mg/m2 of doxorubicin (IVA2 protocol). The IVA2 regimen slowed tumor growth, but 13 months after the initiation of therapy, the patient died of neoplastic cachexia. Although chemotherapy is generally ineffective in most cases of malignant schwannoma, we did experience some positive results with the IVA2 protocol. Therefore, we recommend that this combination be considered as a first-line adjuvant therapy following surgery or as a first-line therapy for patients with inoperable tumors.