Breast schwannoma in a patient with prior breast cancer: a rare case report
Kem-Maria McCook, Nisseau-Bey Zhuri, Chevar South, Zarrin Hosseinzadeh, Theodora Abah, Joel OkoliIntroduction:
Breast schwannoma is a very rare benign peripheral nerve sheath tumor, accounting for approximately 0.2% of all breast tumors. With fewer than 70 cases reported in the literature, the diagnosis is usually challenging and is often not considered.
Case presentation:
We present a case of a 62-year-old Black female with a history of right breast cancer, status post right modified radical mastectomy, and chemoradiation 30 years ago, without prior evidence of recurrence. She presented with a mass in the left breast. Initial diagnostic mammogram and ultrasound reported the mass as a benign lymph node. A repeat mammogram showed interval growth, prompting an ultrasound-guided core-needle biopsy. Histological results were consistent with schwannoma. The patient underwent a left I-125 radioactive seed-localized partial mastectomy for definitive diagnosis and treatment, due to her high risk of breast cancer and preference.
Discussion:
This report highlights the importance of continued clinical and radiographic surveillance in patients with a history of breast cancer, as new breast lesions may warrant further evaluation despite benign-appearing imaging characteristics. Although rare, breast schwannoma should be included in the differential diagnosis of benign breast masses. While breast schwannomas may be managed with observation, in select cases, surgical excision provides a definitive histopathologic diagnosis and is curative when intervention is clinically indicated.
Conclusion:
A low threshold for tissue diagnosis is warranted in breast cancer survivors who present with new breast lesions, even when imaging characteristics appear benign. Management of benign-appearing breast masses should be individualized, and surgical excision for definitive diagnosis and treatment should remain a consideration in cases of interval growth, persistent concern for occult malignancy, or when ongoing imaging surveillance poses a significant burden or inconvenience to the patient.