Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma Protuberans

Thomas Mentzel, MD

Cyril Fisher, MD, DSc, FRCPath

Dermatofibrosarcoma protuberans is characterized clinically by an exophytic, multinodular growth in most cases.

Low-power view of a dermatofibrosarcoma protuberans shows the characteristic diffuse infiltration of subcutaneous fat by neoplastic cells that grow along fibrous septa image.



  • Dermatofibrosarcoma protuberans (DFSP)


  • Superficially located low-grade fibroblastic sarcoma

  • Can progress to fibrosarcomatous dermatofibrosarcoma protuberans



  • Incidence

    • Rare neoplasm

    • One of most frequent superficially located sarcomas

  • Age

    • Young adults

    • Rare in childhood or older age

  • Gender

    • Slight male predominance


  • Trunk (chest, back, shoulder, abdominal wall)

  • Proximal extremities > distal extremities

  • Head and neck region

  • Rare in genital areas


  • Slowly growing nodular dermal neoplasm

  • Often history of slow but persistent growth

  • Can show rapid enlargement due to tumor progression

  • Can show rapid enlargement in pregnancy

  • Rarely plaque-like growth


  • Surgical approaches

    • Wide excision (2-3 cm)

  • Adjuvant therapy

    • Imatinib treatment in advanced and metastatic cases


  • Locally aggressive growth

  • Increased number of often repeated local recurrences

  • Metastases extremely rare (< 0.5%)

  • May progress to fibrosarcomatous DFSP


General Features

  • Indurated dermal plaques

  • 1 or more tumor nodules

    • Multiple protuberant tumors are often seen in recurrent cases

  • Firm gray-white cut surface

  • Usually no tumor necrosis

  • Rarely subcutaneous

Sections to Be Submitted

  • Numerous sections have to be submitted

  • Resection margins have to be carefully assessed


  • May reach considerable size


Histologic Features

  • Diffuse infiltration of dermis and subcutis

  • Infiltration along fibrous septa of subcutaneous fat

    • Characteristic honeycomb pattern

    • Tumor cells encase skin appendages

  • Storiform growth pattern

  • Uniform spindled tumor cells

    • Plump spindled or elongated wavy nuclei

    • Only mild cytologic atypia, < 5 mitoses per 10 high-power fields

  • Collagenous stroma with small vessels

  • May contain pigmented melanocytic cells (pigmented DFSP, so-called Bednar tumor)

  • May show prominent myxoid changes (myxoid DFSP)

  • May contain bundles and nests of myofibroblastic cells (DFSP with myoid differentiation)

  • May rarely show flat, plaque-like growth (plaque-like DFSP, atrophic DFSP)

  • May rarely show granular cell changes (granular DFSP)


  • Ill defined, infiltrative

Predominant Pattern/Injury Type

  • Diffuse

Predominant Cell/Compartment Type

  • Spindle

  • Fibroblast

Giant Cell Fibroblastoma

  • Primarily affects children in 1st decade of life, rarely adults

  • Strong male predilection

  • Locally aggressive neoplasm, frequent local recurrence

  • Metastases have not been reported yet

  • Hypocellular, with myxoid to collagenous stroma

  • Spindled tumor cells and scattered mono- &/or multinucleated giant cells

  • Irregular branching angiectoid spaces

Fibrosarcomatous DFSP

  • Represents morphologic form of progression (grade 2 malignancy)

    • 10-15% metastasize, and sometimes cause death

  • Occurs de novo or more rarely in local recurrence

  • Abrupt or gradual fibrosarcomatous transformation

  • Often nodular, rather well-circumscribed growth

  • Cells arranged in cellular “herringbone” fascicles

  • Increased atypia and mitotic index

  • Increased p53 expression

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Dermatofibrosarcoma Protuberans

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