Angiosarcoma Developing in a Vagal Schwannoma: A Rare Case Report

Abstract

Angiosarcoma arising in a schwannoma is extremely rare with only fourteen cases having been reported in the literature to the best of our knowledge. Amongst these fourteen, only five cases developed from vagal schwannoma. We describe a case of epithelioid angiosarcoma arising in a long standing vagal schwannoma in a 41 years male patient. Grossly the tumor was well encapsulated with variegated cut surface. On microscopy the tumor had two distinct components composed of benign schwannoma and malignant angiosarcoma which were further confirmed by immunohistochemistry. On further work up, he was found to have multiple distant metastases. This is the sixth reported case of angiosarcoma arising in a vagal schwannoma. The proposed histogenesis of this rare transformation, its prognostic factors and a review of literature regarding this entity is discussed.

Fig. 1

MRI with contrast: image showing a well defined heterogeneously enhancing soft tissue mass in left parapharyngeal space with hemorrhage

Fig. 2

Gross photographs showing a well encapsulated mass (a), cut surface showing grey white gelatinous areas at the periphery, and rest of the mass showing hemorrhage, necrosis and cystic change (b)

Fig. 3

Well encapsulated spindle cell tumor with hypercellular Antoni A areas (inset Verocay bodies) (a), and hypocellular Antoni B areas (b) (H&E ×10)

Fig. 4

Anastomosing vascular spaces lined with atypical endothelial cells (a ×10), epithelioid morphology and increased mitotic activity with some atypical mitoses (b ×40) (H&E)

Fig. 5

IHC (a–f) S100—schwann cells show positivity (a) while atypical endothelial cells are negative for S100 (b). CD 31—atypical endothelial cells show positivity (c) while schwann cells are negative for CD 31 (d). Ki 67—atypical endothelial cells show high proliferative activity—40–50 % (e) while schwann cells show low proliferative activity—1–2 % (f)

Fig. 6

PET CT scan showing residual disease in left lateral neck (a), FDG avid lesion in the liver (b), metastatic angiosarcoma in the liver (c H&E ×10), and tumor cells showing positive staining for CD 31 (d)