SCHWANNOMA OF THE BREAST MIMICKING A FIBROEPITHELIAL TUMOR: A CASE REPORT

Darko Dimitrievski; Anastasija Demirovska; Magdalena Bogdanovska Todorovska; Slavica Kostadinova Kunovska

Darko Dimitrievski Institute of Pathology, Faculty of Medicine, University Ss. Cyril and Methodius, Skopje, Republic of North Macedonia
Anastasija Demirovska Institute of Pathology, Faculty of Medicine, University Ss. Cyril and Methodius, Skopje, Republic of North Macedonia
Magdalena Bogdanovska Todorovska Institute of Pathology, Faculty of Medicine, University Ss. Cyril and Methodius, Skopje, Republic of North Macedonia
Slavica Kostadinova Kunovska Institute of Pathology, Faculty of Medicine, University Ss. Cyril and Methodius, Skopje, Republic of North Macedonia

Abstract

Schwannomas are benign peripheral nerve sheath tumors that most often occur as solitary lesions in the extremities and head and neck region. Involvement of the breast is rare and can mimic more common breast neoplasms on imaging.

We report a 55-year-old woman with a one-year history of painful, palpable right breast lump. Ultrasound demonstrated a well-circumscribed, round, solid, hypoechoic nodule with diameter of 2 cm and regular margins, raising suspicion for a fibroepithelial tumor. The patient underwent tumorectomy without preoperative needle biopsy.

On gross inspection, the lesion was encapsulated and tan-white. Histologic examination revealed a benign spindle cell neoplasm with alternating hypercellular Antoni A and hypocellular Antoni B areas. Tumor cells showed strong, diffuse positive immunohistochemical signal for S-100 and Vimentin, supporting the diagnosis of schwannoma.

This case highlights breast schwannoma as an important, though uncommon, consideration in the differential diagnosis of well-defined breast masses. Because breast schwannomas show no specific mammographic or ultrasonographic features, definitive diagnosis relies on histopathologic evaluation and immunohistochemistry. Awareness of this entity may help prevent misclassification of lesions such as fibroadenoma, phyllodes tumor, or breast carcinoma.

Keywords: breast, schwannoma, peripheral nerve sheath tumor, S-100, spindle cell neoplasm

Author Biography

Darko Dimitrievski, Institute of Pathology, Faculty of Medicine, University Ss. Cyril and Methodius, Skopje, Republic of North Macedonia

Leading author, a senior resident at the Institute of Pathology

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