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

Abstract

A 79-year-old woman with a newly detected oval circumscribed lump in subcutaneous location on mammography and ultrasound turned out to be a Schwannoma after ultrasound-guided core needle biopsy. A 72-year-old woman with breast cancer in medical history demonstrated a new axillary mass in follow up, initially regarded as a lymph node metastasis. Core needle biopsy did not lead to a sufficient diagnosis. Pathologic examination after intraoperative sampling revealed a Schwannoma. These 2 case reports illustrate the importance of diagnostic imaging and remind to include Schwannomas in the differential diagnosis of breast and axillary masses.

Axillary schwannoma mimicking lymph node metastasis-associated breast cancer: a case report

“…In particular, there are several problems when distinguishing schwannomas from lymph node metastasis. First, the two tumors resemble each other in imaging findings [ 4 – 8 ]. Schwannoma in the axillary region is very similar to swollen lymph nodes on CT [ 4 ] and has a low T1 signal and high T2 signal on MRI, as does lymph node metastasis [ 8 ].…”

“…First, the two tumors resemble each other in imaging findings [ 4 – 8 ]. Schwannoma in the axillary region is very similar to swollen lymph nodes on CT [ 4 ] and has a low T1 signal and high T2 signal on MRI, as does lymph node metastasis [ 8 ]. In the present case, lymph node metastasis was initially suspected based on imaging findings.…”

“…There is a risk of iatrogenic vascular or nerve injury at the time of puncture. Therefore, some patients require an excisional biopsy to obtain an accurate diagnosis [ 5 , 7 , 8 ].…”

“…In addition, only 5% of sporadic peripheral nerve schwannomas occur in the upper extremities [ 2 ]. To the best of our knowledge, patients with an axillary schwannoma associated with breast cancer are extremely rare, and the previous reports are also limited [ 3 – 8 ]. In the clinical setting, there is great concern about whether such a tumor in the axillary region is a lymph node metastasis.…”

Right breast schwannoma in a male: A rare case report

“…Schwannomas are rare in breast and usually mistaken for other kinds of benign to malignant masses like fibroadenomas, phyllodes tumor, mesenchymal tumors or even breast carcinomas. Though schwannomas are benign, risk of malignancy within the schwannomas are higher in patients with neurofibromatosis [2] , [8] .…”