PMC4772937_01
a Marked nipple enlargement with multiple bluish areas and myxoid appearance. b Alcian blue stain highlighting the myxoid nature of the proliferation.
dpa-0001-0047-g01.jpg
PMC4772937_01_dpa-0001-0047-g01.jpg
F1
Histopathologically, the specimen contained a myxoid lesion centered in the nipple area, which was noticeably enlarged (fig. 1). The proliferation presented a conspicuous multilobular pattern (fig. 1, 2) with thick fibrocollagenous bands interspersed among the myxoid lobules. Alcian blue at a pH of 2.5 and colloidal iron stains highlighted the myxoid stroma (fig. 1b).
Multifocal areas of myxoid proliferation with ill-defined boundaries intermixed with sclerotic tissue.
dpa-0001-0047-g02.jpg
PMC4772937_01_dpa-0001-0047-g02.jpg
F2
The proliferation presented a conspicuous multilobular pattern (fig. 1, 2) with thick fibrocollagenous bands interspersed among the myxoid lobules.
Fibrocollagenous septa containing preexisting ducts between two foci of myxoid proliferation with stellate cells surrounded by clear halos.
dpa-0001-0047-g03.jpg
PMC4772937_01_dpa-0001-0047-g03.jpg
F3
Occasional breast ducts were observed in the fibrocollagenous septa (fig. 3), but they were completely absent from the myxoid nodules. In addition, some stellate cells surrounded by clear halos of a chondroid appearance were observed focally (fig. 3, 5).
Loosely arranged fascicle of spindle cells with slender cytoplasms in a myxoid background.
dpa-0001-0047-g04.jpg
PMC4772937_01_dpa-0001-0047-g04.jpg
F4
There were also microscopic foci with higher cellular density, usually having a myofibroblastic appearance (fig. 4).
At the base, the lesion boundaries tended to be well demarcated.
dpa-0001-0047-g05.jpg
PMC4772937_01_dpa-0001-0047-g05.jpg
F5
In addition, some stellate cells surrounded by clear halos of a chondroid appearance were observed focally (fig. 3, 5). The peripheral outline was irregular at the base of the lesion, with foci of the myxoid tissue merging imperceptibly with the breast fat tissue, whereas in other areas, the lesion was quite well circumscribed (fig. 5).
The immunoprofile was characterized by a diffuse expression of CD34 (a), weak-to-moderate expression of actin (b) and weak but noticeable expression of S100 protein (c).
dpa-0001-0047-g06.jpg
PMC4772937_01_dpa-0001-0047-g06.jpg
F6
Immunohistochemical studies demonstrated a diffuse and intense expression of CD34 (fig. 6a); alpha-smooth muscle actin (fig. 6b), calponin and S100 (fig. 6c) were also expressed diffusely, albeit with faint-to-moderate intensity, whereas desmin was negative.