Nodular Fasciitis

Nodular Fasciitis

Elizabeth A. Montgomery, MD

Hematoxylin & eosin shows low magnification of nodular fasciitis. The lesion is nodular and reminiscent of granulation tissue. Note the moderate circumscription.

Hematoxylin & eosin shows a loose storiform pattern with cystic spaces image and background lymphocytes and extravasated erythrocytes.



  • Nodular fasciitis (NF)


  • Pseudosarcomatous fasciitis

  • Subcutaneous pseudosarcomatous fibromatosis


  • Rapidly growing myofibroblastic mass-forming proliferation that is often cellular and mitotically active but behaves in benign fashion

    • Typically displays loose storiform pattern, cystic spaces, and strands of keloid-like collagen

  • Intravascular fasciitis is rare variant of nodular fasciitis arising from small or medium-sized vessels

    • Presents as soft tissue mass with focal intravascular extension or multinodular predominantly intravascular mass

    • Despite intravascular location, lesion behaves in benign fashion with no tendency to recur or metastasize

  • Cranial fasciitis involves soft tissues of scalp and underlying skull of infants

    • Usually erodes bone but may penetrate through bone to involve meninges

    • Fragments of bone may be seen at periphery of lesion

    • Birth trauma presumed inciting stimulus



  • History of local trauma in subset



  • Incidence

    • Uncommon but comparatively common among soft tissue lesions

  • Age

    • 3rd-4th decades

  • Gender

    • M = F


  • Subcutaneous mass


  • Simple excision usually curative


  • Excellent prognosis

  • Seldom recurs, even if incompletely excised


General Features

  • Well-marginated but unencapsulated

  • Variable mucoid appearance

Sections to Be Submitted

  • Usually entire lesion is submitted


  • 2-3 cm mass


Histologic Features

  • Loose storiform, “feathery” pattern with tissue culture appearance, variable myxoid stroma, cystic spaces, strands of keloid-like collagen

  • Mitoses present but no atypical forms

  • Osteoclast-like giant cells found in most lesions if sought

    • Can be highlighted by CD68

  • Scattered lymphocytes but essentially no plasma cells

  • Extravasated erythrocytes

    • No associated hemosiderin

  • 3 forms reported: Myxoid, cellular, and fibrous

    • Loose correlation with duration of lesions

    • Myxoid lesion often resected within 10 days after coming to clinical attention

    • Cellular and fibrous forms resected after longer intervals

    • Some lesions show several patterns

  • Myofibroblastic differentiation results in expression of some smooth muscle immunohistochemical markers

    • Lesions can be mistaken for leiomyosarcomas when mitotically active

Predominant Pattern/Injury Type

  • Localized

Predominant Cell/Compartment Type

  • Mesenchymal, spindle

Variant Forms

  • Nodular myositis

    • Same as nodular fasciitis but intramuscular

    • Debate as to whether such cases are instead early myositis ossificans

  • Intravascular fasciitis

    • Typically affects head and neck and distal extremities

    • More solid than classic form

    • Typically displays abundant osteoclast-like giant cells

    • Easily mistaken for leiomyosarcoma based on mitoses

  • Cranial fasciitis

    • Lesion of infants sometimes attributed to birth trauma

    • Similar morphology to that of nodular fasciitis but more myxoid background

    • Some reported examples may be fibromatoses

    • Can involve skull itself

  • Subsets occur in specific locations

    • Spermatic cord (proliferative funiculitis)

    • Within nerves



  • Shows myofibroblastic cells

    • Lesions are cellular, which can lead to erroneous impression of sarcoma on aspiration cytology

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Nodular Fasciitis
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