Dermatofibrosarcoma protuberans of the breast: A case report

Abstract

Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumor of subcutaneous tissue characterized by slow infiltrative growth. The tumor occurs in patients of all ages, with the highest frequency occurring between the second and the fifth decades of age. Genetically, DFSP is characterized by a reciprocal translocation t(17;22)(q22;q13), or more often, as a supernumerary ring chromosome involving chromosomes 17 and 22. Standard treatment of a localized tumor is surgical excision with wide margins. In the present study, a case report of a 43-year-old woman with a growing tumor in the left breast is discussed. The patient underwent breast-conserving surgery. Histological and cytogenetic examinations of the tumor resulted in a diagnosis of DFSP. The clinical and morphological characteristics of the tumor, in addition to the treatment options, were also evaluated.

Keywords: breast tumor; dermatofibrosarcoma protuberans.

Figure 1.

Dematofibrosarcoma protuberans of the breast. (A) A circumscribed round, partially lobulated radiopaque lesion with sharp contour was revealed following an X-ray digital mammography of the left breast. (B) A round tumor protruded above the surface of the skin in the medial quadrants of the left breast. (C) Gross examination revealed a 12.0×9.0×8.0-cm segment of breast tissue with a circumscribed 6.2×6.2×5.0-cm tumor, which was tan-grey colored on the cut surface.

Figure 2.

Hematoxylin-eosin staining of tissue from a patient with dermatofibrosarcoma protuberans of the breast. (A) Tumor growth into the skin demonstrated a zone of uninvolved dermis with chronic inflammatory infiltrate and spindle cell proliferation adjacent to the overlying epidermis (magnification, ×100). (B) Tentacles of tumor surround the residual structures of the mammary glands (magnification, ×200). (C) Highly cellular and tight storiform patterning of cells that are monomorphic, thin, and spindly with hyperchromatic nuclei (magnification, ×200). (D) Mitotic figure without atypical mitoses (magnification, ×400).

Figure 3.

Immunohistochemical examination of tissue from a patient with dermatofibrosarcoma protuberans of the breast (200x). (A) Strong and diffuse staining for CD34 indicating spindle cell proliferation. (B) The index of Ki-67 proliferative activity was 10% positive. (C) Focal weak staining for smooth muscle actin and (D) irregular weak/middle staining for CD10. CD, cluster of differentiation.

Figure 4.

Detection of chromosomal translocation t(17;22)(q22;q13) in paraffin-embedded tissue from a patient with dermatofibrosarcoma protuberans of the breast using gene-specific probes by FISH. (A) COL1A1 and (B) PDGFB break-apart probes: Interphase nuclei with yellow signals indicate an intact COL1A1 (PDGFB) locus. Orange signals denote additional copies of an unbalanced rearranged COL1A1 (PDGFB) locus. (C) COL1A1/PDGFB dual fusion probe: FISH detects separate orange and green normal signals, and multiple yellow (orange/green) fusion signals indicate COL1A1/PDGFB translocation. PDGFB, platelet derived growth factor subunit B; COL1A1, collagen type I α 1 chain; FISH, fluorescence in situ hybridization.