Malignant peripheral nerve sheath tumors arising from schwannomas: case series and literature review

Abstract

A malignant peripheral nerve sheath tumor (MPNST) arising from a schwannoma is extremely rare, with limited literature on its clinicopathologic features. Here, we present a case series and literature review on patients with MPNSTs arising from schwannomas. We performed a retrospective review of patients from our institution's records to identify those with MPNSTs arising from schwannomas. We conducted a search for additional cases from the literature utilizing PubMed. 20 patients (including 2 at our institution and 18 from 16 prior publications) were identified. The patients aged 22-93 (mean 52) years, and 63% were females. Histologically, while most MPNSTs arising from schwannomas were of epithelioid-type, 7 tumors (including 2 at our institution) were of conventional spindle-cell type. All 20 patients underwent surgical excision, while a subset received additional radiotherapy and/or chemotherapy. In 17 patients with available follow-up, the overall survival was 2-72 (median 12) months. MPNSTs rarely arise from schwannomas and should be considered in patients with a clinical diagnosis of schwannoma, however, with atypical radiologic or clinical features. MPNSTs arising from schwannomas can show epithelioid or spindle-cell histology and harbor an aggressive course, even with surgical excision and adjuvant treatment.

An unexpected case of lower lip benign Schwannoma: diagnosis, management and review of literature

“…Furthermore, since only a few cases of malignant transformation of a benign Schwanommas have been reported, wide local excision is not preferred as primary surgery. 11 However, presence of malignancy warrants removal of surrounding neovascular, subcutaneous, and bony tissue along with the tumor mass. Adjuvant radiotherapy or chemotherapy are recommended for higher stages malignant schwanommas.…”

Endobronchial ultrasound-guided transbronchial needle aspiration as a diagnostic modality for schwannoma: A case report

“…A malignant peripheral nerve sheath tumor arising from a schwannoma is extremely rare. [ 3 ] Patients are usually asymptomatic when the tumor is small. However, as the tumor increases in size, it may cause compression with adjacent vital organs, nerves, and blood vessels, which may manifest as chest and back pain, Horner syndrome, dysphagia, cough, shortness of breath, hoarseness, wheezing, superior vena cava syndrome, or muscle weakness.…”

“…Most schwannomas, however, are benign and usually grow slowly; as such, for a malignant peripheral nerve sheath tumor to arise from a schwannoma is extremely rare. [3] Surgical excision is the preferred treatment for schwannomas [2,4] and the prognosis is favorable, with a typical 5-year survival rate of 97% after surgery. [5] The use of computed tomography (CT), magnetic resonance imaging (MRI), and/or positron emission tomography-CT (PET-CT) enables a precise preoperative diagnosis and the design of an appropriate surgical treatment strategy.…”

“…Most schwannomas, however, are benign and usually grow slowly; as such, for a malignant peripheral nerve sheath tumor to arise from a schwannoma is extremely rare. [ 3 ] Surgical excision is the preferred treatment for schwannomas [ 2 , 4 ] and the prognosis is favorable, with a typical 5-year survival rate of 97% after surgery. [ 5 ]…”

Mesenchymal tumours of the pleura: review and update

“…The diagnosis of malignant peripheral nerve sheath tumour requires the fulfilment of at least one of the following conditions: (1) sarcoma arising from a nerve or preexisting benign peripheral nerve sheath tumour (frequently neurofibroma, rarely schwannoma); (2) sarcoma arising in the setting of neurofibromatosis type 1; and (3) sarcoma with immunohistochemical evidence of Schwannian differentiation. 113,[118][119][120] Most malignant peripheral nerve sheath tumours are sporadic/de novo; a minor subset is associated with neurofibromatosis type 1, preexisting nerve/benign nerve sheath tumour, or prior radiotherapy. Like schwannoma, intrathoracic malignant peripheral nerve sheath tumour usually originates from the posterior mediastinum, rarely from the pleura or lung.…”