Breast Schwannoma: a rare case report of a benign neoplasm in the upper outer quadrant of the right breast

Abstract

Mammary schwannoma is a rare benign neoplasm that originates from the Schwann cells of peripheral nerves, representing a small fraction of breast masses. This case report describes a patient with a painless nodule in the upper lateral quadrant of the right breast. She underwent surgical excision of the lesion, which was sent for histopathological analysis. The examination revealed a fusocellular mesenchymal neoplasm with areas of metaplastic bone tissue, suggesting the need for further diagnostic workup with immunohistochemistry. The result confirmed a mammary schwannoma through the expression of S100 protein, characteristic of this type of tumor. This case highlights the rarity of mammary schwannomas, a benign neoplasm underreported in medical literature, and emphasizes the importance of careful differential diagnosis, as clinical and imaging findings can mimic more common conditions.