Contributed by Andrew Walls, MD
Published on line in June 2006
The patient was a 74-year-old woman with no family history of breast cancer who presented for a screening mammogram. An asymmetric density was seen in the right breast, and she was recalled for diagnostic mammogram and ultrasound 2 weeks later. The mammogram confirmed the presence of an ill-defined density in the posterior right upper outer quadrant, with some evidence of spiculation. No suspicious calcifications were seen. Ultrasound showed 2 immediately adjacent, ill-defined, hypoechoic masses in the right upper outer quadrant, 8 x 11 mm and 5 x 4 mm, with irregular margins. No axillary lymphadenopathy was noted (Fig. 1).
She underwent an ultrasound guided core biopsy of the suspicious area. The histology showed a diffuse, scattered infiltrate of small to medium sized spindle cells in a somewhat myxoid stroma. There was an increased amount of dense fibrous tissue and focal collections of adipose tissue (Figs. 2, 3, 4 and 5). There were rare benign ducts (Fig. 6). Necrosis was absent. On high-powered view, the spindle cells showed mild pleomorphism with dark chromatin, but no prominent nucleoli. Mitoses were not apparent (Fig. 7).
A panel of immunohistochemical stains was performed on the tissue, with the following results (See labeled figures):
|Cytokeratin 5/6||diffusely positive in the spindle cells|
|Cytokeratin AE1/3||diffusely positive in the spindle cells|
|Cytokeratin 903||diffusely positive in the spindle cells|
|P63||diffusely positive in the spindle cells|
|Smooth muscle actin||highlights stromal vascular structures|
Finally, immunohistochemical staining was performed for estrogen receptor, progesterone receptor and Her-2/Neu, which were all completely negative.