Breast schwannoma

Abstract

Schwannomas arise from Schwann cells of the peripheral nerve sheath. The most common locations include the head, neck, and extensor surfaces of the extremities. Intramammary schwannomas are very rare and account for only 2.6% of schwannomas. A review of the English literature reveals 27 such cases of breast schwannoma. In this paper we describe another such rare case.

Figure 1

(a) Mediolateral view of the left breast shows an 8 mm well-defined ovoid mass in the left upper outer quadrant (arrow). The mass (arrow) has increased in size when compared to previous mammogram. (b) The mass (arrow) as seen on the previous years mammogram. (c) There is a skin marker overlying the mass (arrow) on the craniocaudal view.

Figure 2

Ultrasound with a 17 MHZ linear probe. (a) demonstrates a 7 mm well-defined, complex hypoechoic mass within the breast superficially, abutting the skin (white arrows). (b) The mass shows significant central vascularity.

Figure 3

Histological examination. (a) shows an encapsulated mass consisting of monomorphic spindle cells with pointed basophilic nuclei (Antoni A tissue), set in a variable collagenous stroma (low power). Given limited excision of the encapsulated mass, adjacent normal breast parenchyma is not visualized. (b) shows areas of cells with parallel arrays of nuclear palisading known as Verocay bodies (high power).