1 - DERMATOFIBROSARCOMA OF THE BREAST: A CASE REPORT

Abstract

Dermatofibrosarcoma (DFS) is a rare low-grade fibroblastic mesenchymal tumor derived from the dermis. The lesion
accounts for approximately 1% of all soft-tissue sarcomas and less than 0.1% of all malignancies, with an annual incidence
of 4.2–4.5 cases per million. It occurs most frequently between the second and fifth decades of life and usually appears
in the dermis and subcutaneous tissue. DFS occurs more commonly in the trunk (42%–72%), and breast involvement is
uncommon and occurs due to the infiltration of previous dermal involvement. We report a case of a 40-year-old female
patient with a history of a violaceous nodulation that was hardened and not adhered to deep planes measuring approximately 5 cm in the inferomedial quadrant of the left breast, whose biopsy was performed in an external unit revealing a
DFS. Magnetic resonance imaging of the breast showed a nodule with thickening of the adjacent skin in the aforementioned
topography, measuring 3.1×3×2.9 cm, in addition to another nodular image with similar characteristics, compatible with
multifocal involvement. She underwent quadrantectomy and immediate reconstruction with a myocutaneous flap of the
fat-grafted latissimus dorsi muscle. A surgical specimen containing two nodules, measuring 2.8 and 2.5 cm, respectively,
with a result compatible with a DFS with free surgical margins was analyzed. Immunohistochemistry revealed native
estrogen and progesterone receptors, positive CD34 in tumor cells, and positive Ki67 in less than 5% of cells. The patient
remains under clinical follow-up at our service, with no evidence of recurrence of the lesion, currently with annual consultations for physical examination and checking of breast ultrasound and bilateral mammography examinations.