Soft tissue
Fibroblastic / myofibroblastic
fibrosarcoma
Myxoinflammatory fibroblastic sarcoma
Topic Completed: 1 April 2013
Minor changes: 10 December 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Myxoinflammatory fibroblastic sarcoma [title]
Table of Contents
Definition / general | Epidemiology | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosisCite this page: Morrison A. Myxoinflammatory fibroblastic sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuemyxoinflammatory.html. Accessed January 22nd, 2021.
Definition / general
- Rare low grade sarcoma of hands and feet with myxoid stroma, inflammation and virocyte-like cells (Am J Surg Pathol 2014;38:1)
- Also called inflammatory myxohyaline tumor of the distal extremities with virocyte or Reed-Sternberg-like cells, acral myxoinflammatory fibroblastic sarcoma
- First described in 1998 simultaneously by Montgomery et al (Mod Pathol 1998;11:384) and Meis-Kindblom and Kindblom (Am J Surg Pathol 1998;22:911)
Epidemiology
- Rare; men and women of all ages (mean age 48 years) with slow growing mass, 77% in hands or feet (J Cutan Pathol 2008;35:192) but can occur in other sites
Case reports
- 13 year old girl with back tumor (Int J Dermatol 2008;47:68)
- 28 year old woman with 2 cm mass on big toe (Case of the Week #296)
- 29 year old man with finger mass (Arch Pathol Lab Med 2005;129:1343)
- 30 year old man with elbow mass (Arch Pathol Lab Med 2006;130:e35)
- 48 year old woman with temporal mass (Am J Dermatopathol 2012;34:663)
- Groin mass (J Cutan Pathol 2007;34:276)
- Neck mass (J Cutan Pathol 2005;32:375)
Treatment
- Wide local excision with or without radiation therapy (Cancer 2010;116:5733) may recur locally, distant metastases are rare (J Cutan Pathol 2008;35:186, Virchows Arch 2003;442:25)
Clinical images
Contributed by Mark R. Wick, M.D.
Gross description
- Multinodular, poorly defined, usually small but may be up to 8 cm, often involves joints and tendons
- White and gelatinous with fibrous and myxoid zones
Microscopic (histologic) description
- Multinodular tumor of polymorphous cells with infiltrative margins in subcutis and often dermis, but only rarely skeletal muscle
- Three components:
- Acute or chronic inflammatory cells
- Areas of fibrosis or hyalinized stroma
- Areas of myxoid extracellular matrix with tumor cells with these features:
- Epithelioid or spindled, occasionally large with bizarre nuclei and prominent nucleoli resembling viral inclusions or Reed-Sternberg cells
- Multivacuolated cells resembling pleomorphic lipoblasts (pseudolipoblasts - tumor cells with cytoplasmic vacuoles containing myxoid material), or
- Giant cells with emperipolesis; 0 - 1 MF / 10 HPF, no atypical forms, no / rare necrosis
Microscopic (histologic) images
Contributed by Mark R. Wick, M.D.
Toe
AFIP images
Myxoid nodule, characteristic ganglion-type cells, prominent nucleoli
Case #296
Images hosted on other servers:
Alternating fibrous and myxoid regions
Modest infiltrate of inflammatory cells
Acute inflammatory cells
Nodules with tumor cells
Sheetlike proliferation of spindle cells
Spindle cells with prominent nucleoli
Cytology description
- Spindle, epithelioid, lipoblast-like and ganglion-like cells in myxoid background with prominent inflammatory infiltrate, cases may not display all features
- Must be cautious in diagnosis of soft tissue lesions by cytology alone (Acta Cytol 2007;51:231, Cytopathology 2003;14:73, Diagn Cytopathol 2012;40:E144)
Cytology images
Contributed by Mark R. Wick, M.D.
Toe, FNA
Images hosted on other servers:
Figure 1
Negative stains
- CD45, T and B cell markers
Electron microscopy description
- Fibroblastic features of abundant rough endoplasmic reticulum and mitochondria, intermediate filaments
- Lipoblast like cells have cytoplasmic pseudoinclusions with extracellular mucin
Molecular / cytogenetics description
- Complex and heterogeneous karyotypes, inconsistent between cases, including aneuploidy (Virchows Arch 2007;451:923), ring chromosomes (Cancer Genet Cytogenet 2004;152:61), t(2;6) (Cancer Genet Cytogenet 2007;177:139), t(1;10)(p22;q24) resulting in gene rearrangements of TGFBR3 and MGEA5 which can also be seen in hemosiderotic fibrolipomatous tumor (HFLT) (Am J Surg Pathol 2010;34:1723)
Differential diagnosis
- Epithelioid sarcoma: most cells are round with dense eosinophilic cytoplasm, strongly keratin+, loss of INI1 (SMARCB)
- Hodgkin lymphoma: lacks giant cells and lipoblast-like cells, tumor cells have different staining patterns
- Myxofibrosarcoma: rare in soft tissues of hands and feet, more frequent mitotic figures with atypical forms, no inflammatory infiltrate
- Pleomorphic liposarcoma: true pleomorphic lipoblasts, rare in soft tissues of hands and feet, more frequent mitotic figures with atypical forms, no inflammatory infiltrate
- Rosai-Dorfman disease: emperipolesis, but no intranuclear viral-like inclusions, S100+, usually not myxoid
- Tenosynovitis: no enlarged atypical cells
