Low Grade Fibromyxoid Sarcoma

OVERVIEW

Low grade fibromyxoid sarcomas (LGFMS) are a rare malignant tumour that can occur at any age but predominantly affect young adults.  The tumours present as a painless mass and occur commonly in the extremities or trunk, particularly the thigh. This tumour classification accounts for 15-20% of liposarcomas and represents 5% of all soft tissue sarcomas in adults.

About 95% of cases harbour a t(7;16)(q33;p11) that fuses the 5’FUS to the 3’CREB3L2.  Another 5% of cases can have a t(11;16)(q11;p11) resulting in a fusion of FUS and CREB3L1. There are also rare reports of an EWSR1-CREB3L1 rearrangement (t(11;22)(q11;q12)).

TEST REQUIREMENTS

  • Completed CGL Cytogenetics Solid Tumour Testing requisition form
  • FFPE Tumour specimen (see Specimen Guidelines, Cytogenetics FISH FFPE test type)
    • An H&E stained slide with the tumour region circled, and the estimated % tumour content written in the Tumour Content field of the requisition.  NOTE: A minimum of 10% tumour and at least 200 nuclei is required.
    • Specimen block and/or at least one unstained slide for each probe requested.

TURN-AROUND TIME

Results are reported within fourteen days from receipt of specimen and completed requisition form.  

RESULTS REPORTING

  • Results of this assay are reported as Positive for a FUS and/or CREB3L2 rearrangement or Negative for a FUS and/or CREB3L2 rearrangement.
  • FUS and CREB3L2 rearrangements have also been identified in sclerosing epithelioid fibrosarcomas.

METHOD

FISH analysis is performed on the provided paraffin embedded tissue using the FUS (16p11) dual-colour, break-apart probe (Vysis) and an “in-house” dual colour, break-apart probe (RP11-115N3, RP11-691P5) to CREB3L2 (7q33).

REFERENCES

  1. Prieto-Granada et al.  Genes Chromosomes Cancer (2015)  PMID: 25231134  
  2. Lau et al.  Am J Dermatopathol  (2011)  PMID: 23588368
  3. Bartuma  et al. Cancer Genet Cytogenet (2010)  PMID: 20471519
  4. Guillou et al. Am J Surg Pathol (2007) PMID: 17721195
  5. Matsuyama et al.  Am J Surg Pathol  (2006)  PMID: 16931951