Abstract
We report a rare case of desmoid tumor in the chest wall with invasion into the left breast. A 30-year-old woman noticed a mass in her left breast in February 2006. She had a medical examination in our hospital in July 2006, when her breast pain had gradually become worse. At first, mammography showed neither a mass lesion nor bilateral malignant calcification. Ultrasonography showed an irregular hypoechoic mass occupying most of the deep breast tissue, a finding highly suggestive of scirrhous carcinoma. Fine-needle aspiration revealed a classII lesion with no cellular atypia. Core needle biopsy revealed proliferation of collagenous fiber and invasion of benign inflammatory cells. However, MRI showed gradual enhancement without a choline peak on MRS, indicative of benign fibrous tissue. For a second look, ultrasonography, elastography, and the finger compression maneuver were added. Elastography showed the mass lesion to cover a wide area on the chest wall and to be relatively harder than the mammary gland. These MRI ultrasonography, and fine needle biopsy findings led us to consider the possibility of a desmoid tumor. Resection of the mass lesion and part of the pectoralis major muscle was then carried out. Pathologic evaluation of the lumpectomy tissue with immunostaining showed a desmoid tumor comprising fibroblast-like cells.
