Intramammary schwannoma: a palpable breast mass

Abstract

Schwannomas are benign tumors arising from the peripheral nerve sheath, commonly occurring in the head, neck, and extensor surfaces of the extremities. They can be associated with neurofibromatosis type II. Our case describes a 48-year-old woman with a 2-week history of a left-sided palpable breast mass. She was referred to radiology, where additional imaging revealed a 1.1-cm mass. A biopsy was performed; histology revealed an intramammary schwannoma. Mammography findings include a well-defined mass without calcification. Ultrasound images have shown hypoechoic, encapsulated, and well-defined lesions without calcification. Histologically, schwannomas reveal alternating Antoni A and Antoni B cellular areas. Schwannomas are also S100-positive on immunohistochemistry. This case is best categorized as a BI-RADS 4A lesions. This case report highlights the importance of both imaging and pathology in the diagnosis of breast neoplasms. Although breast schwannomas are not a common entity, they are an important consideration when evaluating a breast mass.

Two case reports: Breast schwannoma and a rare case of an axillary schwannoma imitating an axillary lymph node metastasis

“…Only 2.6% of all Schwannomas are located intramammary and 5% in the axillary region [2 , 3 , [7] , [8] – 9] . Histologically they demonstrate spindle cells which are arranged in so called Antoni A and B tissue, areas with nuclear palisading (Verocay bodies) and strong expression of S100 [10 , 11] .…”

“…An intramammary subcutaneous location of Schwannomas is common among the reported cases in literature and can lead to the suspicion of a mesenchymal tumor [2 , 4 , 10] . However, we followed the external recommendation of an ultrasound-guided core needle biopsy and in spite of a typical histology with lack of atypia a surgical excision was recommended, following the patients wish.…”

Bilateral Neurofibromas of the Nipple-Areolar Complex: A Case Report and Approach to Diagnosis

“…Neurofibromas are one of the two types of benign breast peripheral nerve sheath tumours (PNST), the other being breast schwannomas [ 1 , 4 , 8 , 9 ]. Schwannomas are the most common of the PNST with a low malignant potential and can occur sporadically or in association with neurofibromatosis II (NFII) in 3% of cases [ 9 ]. Microscopically neurofibromas and schwannomas are typically composed of spindle shaped cells with elongated wavy nuclei with no features of atypia or areas of high mitotic activity.…”

“…On IHC they display positivity for S100 protein. More diffuse and uniform S100 staining patterns are seen in schwannomas [ 6 , 7 , 9 ].…”

Cellular schwannoma of the breast: A case report and review of literature

“…As a whole, there have been a few of reports about benign schwannoma of breast. [8][9][10][11] Malignant schwannoma of the breast is unusual. [12][13][14] However, the cellular schwannoma of breast have not been reported to date.…”