PMC8243102_01
(a) Coronal T1 and (b) sagittal T1. Increased soft tissue with
encasement (yellow arrows) is noted of the right brachial plexus
divisions and cords superior to the subclavian artery with
extension to the axilla.
10.1177_2050313X20985646-fig1.jpg
PMC8243102_01_10.1177_2050313X20985646-fig1.jpg
fig1-2050313X20985646
Magnetic resonance imaging (MRI) revealed a soft tissue mass encasing the right brachial plexus divisions and cords without axillary lymphadenopathy, as well as severe chronic rotator cuff arthropathy with a large shoulder effusion (Figure 1).
(a) Adipose tissue with invasive carcinoma inducing desmoplastic
response. Reactive changes including patchy lymphocytic
infiltrates and fat necrosis are present (H&E, x4). (b)
Carcinoma is present in "single file" cords. Cells are large,
have increased nuclear: cytoplasmic ratio, variably prominent
nucleoli, and low mitotic activity (H&E, x40). (c)-(f)
Neoplastic cells are strongly immunoreactive for CK7 (c), GATA3
(d), ER (E, Allred 8 of 8), and PR (F, Allred 8 of 8) (x20).
10.1177_2050313X20985646-fig2.jpg
PMC8243102_01_10.1177_2050313X20985646-fig2.jpg
fig2-2050313X20985646
Immunostaining was consistent with primary breast cancer that was estrogen receptor (ER) and progesterone receptor (PR) positive, and Her2/neu negative (Figure 2).