Bone & joints

Other chondrogenic tumors

Chondromyxoid fibroma


Editorial Board Member: Borislav A. Alexiev, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Qurratulain Chundriger, M.B.B.S.
Nasir Ud Din, M.B.B.S.

Topic Completed: 17 December 2020

Minor changes: 21 December 2020

Copyright: 2003-2021, PathologyOutlines.com, Inc.

PubMed Search: Chondromyxoid fibroma [TIAB] pathology review [PT]

Qurratulain Chundriger, M.B.B.S.
Nasir Ud Din, M.B.B.S.
Page views in 2020: 9,187
Page views in 2021 to date: 10,907
Cite this page: Chundriger Q, Ud Din N. Chondromyxoid fibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bonechondromyxoidfibroma.html. Accessed October 25th, 2021.
Definition / general
  • Benign cartilaginous tumor of young adults, arising in proximal or distal parts of long bones, showing zonal architecture
  • Local recurrence is common; malignant transformation is extremely rare
Essential features
  • Characteristic radiologic appearance; i.e. eccentric lytic lesion with sharp, sclerosed and scalloped intramedullary edges
  • Histologically, zonal architecture comprised of lobules of myxoid to chondroid tissue with intervening spindle and multinucleated giant cells, showing variable coarse calcifications
  • Complete surgical resection is the treatment of choice, with chances of recurrence following simple curettage but no potential for distant metastasis
ICD coding
  • ICD-O: 9241/0 - chondromyxoid fibroma
  • ICD-11: 2E82.Z & XH89S0 - benign chondrogenic tumors, site unspecified and chondromyxoid fibroma
Epidemiology
Sites
Pathophysiology
  • Upregulation of glutamate receptor gene GRM1 coding region of chromosome 6 through recombination with several partner genes in up to 90% of cases (Nat Genet 2014;46:474)
Etiology
  • Unknown
Diagrams / tables

Contributed by Qurratulain Chundriger, M.B.B.S.
Schematic presentation

Drawing showing histology

Clinical features
Diagnosis
  • Requires integration of radiological and histopathological findings
  • Diagnosis can be challenging on a small biopsy specimen (e.g. cytology or needle core)
Radiology description
Radiology images

Contributed by Mark R. Wick, M.D. and Nasir Ud Din, M.B.B.S.
Metatarsal Xray

Metatarsal Xray

Femur Xray

Femur Xray

Tibia Xray Tibia Xray

Tibia Xray

Proximal femur

Proximal femur


Distal tibia

Distal tibia

Proximal tibia

Proximal tibia

Distal tibia

Distal tibia

Metatarsal

Metatarsal



Images hosted on other servers:
Nasal mass

Nasal mass

Sternum

Sternum

Sellar lesion

Sellar lesion

Radius Radius

Radius


Rib Rib Rib

Rib

Sacrum

Sacrum

Metatarsal

Metatarsal

Prognostic factors
  • Around 15% cases may recur, mostly following simple curettage rather than total resection (World J Surg Oncol 2014;12:283)
  • Malignant transformation can occur after radiation therapy
Case reports
Treatment
Clinical images

Images hosted on other servers:
Lesion in mandible Lesion in mandible

Lesion in mandible

Orbital tumor with globe displacement

Orbital tumor with globe displacement

Gross description
  • Lobulated tumor mass with intact periosteum
  • Cut surface is firm, glistening with variable myxoid areas (J Clin Diagn Res 2015;9:XD04)
  • Calcifications may not be seen grossly
Gross images

Images hosted on other servers:
Orbital tumor resection specimen

Orbital tumor resection specimen

Resection of rib tumor

Resection of rib tumor

Microscopic (histologic) description
  • Lobulated architecture; lobules separated by mononuclear spindle cells and admixed multinucleated giant cells
  • Lobules have hypocellular centers and hypercellular periphery
  • Variably myxoid to chondroid stroma, representing various stages of cartilaginous development (Hum Pathol 1998;29:438)
  • Lobules have stellate cells in a myxoid background and reside in lacunae in chondroid areas (Am J Clin Pathol 2001;116:271)
  • Cells have variable pink cytoplasm, bipolar to multipolar cytoplasmic extensions and oval to spindled nuclei
  • Marked nuclear pleomorphism with nucleoli may be seen in some cases
  • Periphery of lobules show spindle shaped fibroblast-like cells and scattered multinucleated osteoclast-like giant cells
  • Low mitotic rate
  • Coarse calcifications may be seen in the stroma, particularly in tumors arising in older age group and unusual sites (Skeletal Radiol 1998;27:559)
  • Hemosiderin deposition and lymphocytes may be seen
  • Necrosis, cystic change or degenerative changes are rare
  • 10% of cases may show associated areas of aneurysmal bone cyst-like appearance (Hum Pathol 1998;29:438)
Microscopic (histologic) images

Contributed by Nasir Ud Din, M.B.B.S.
Confluent nodules with giant cells

Confluent nodules with giant cells

Well defined nodular growth

Well defined nodular growth

Fibroblastic population

Fibroblastic population

Peripheral giant cell proliferation

Peripheral giant cell proliferation

Stellate mesenchymal cells in nodules

Stellate mesenchymal cells in nodules

Adjacent ABC-like areas

Adjacent ABC-like areas


Chondroid differentiation Chondroid differentiation

Chondroid differentiation

Well developed chondroid areas

Well developed chondroid areas

Calcifications

Calcifications

Cytology description
  • Smears are moderately cellular, having fragments of fibrillary myxochondroid tissue, which stains metachromatically (Diagn Cytopathol 2013;41:904)
  • Fragments of spindle cells and variable numbers of osteoclast-like giant cells are seen (Iran J Pathol 2016;11:272)
  • Nuclear atypia may be variable and result in malignant interpretation
  • Calcification may not be seen in cytology smears
Cytology images

Images hosted on other servers:
FNA of metatarsal lesion

FNA of metatarsal lesion

FNA of lytic lesion in femur

FNA of lytic lesion in femur

FNA of metatarsal head lesion

FNA of metatarsal head lesion

Positive stains
  • Chondromyxoid fibroma does not require immunohistochemistry for diagnosis
  • S100 and SOX9: positive in the cells within chondroid lobules (Hum Pathol 1989;20:952)
  • SMA: spindle cells at the periphery of lobules may show some degree of positivity
Negative stains
Electron microscopy description
  • Cells show cytoplasmic processes, intracytoplasmic glycogen and thickening of the nuclear membrane
Molecular / cytogenetics description
  • Not required for reaching diagnosis
  • GRM1 upregulation is highly specific for chondromyxoid fibroma
Videos

Cartilage forming tumors

Sample pathology report
  • Left knee and proximal tibia, curettage:
    • Benign cartilaginous tumor with features favoring chondromyxoid fibroma (see comment)
    • Comment: Correlation with radiological findings is essential.
Differential diagnosis
  • Central chondrosarcoma:
    • Radiographically destructive, osteolytic lesion with invasion into adjacent bone and soft tissue, moth eaten appearance and foci of calcifications
    • Histologically infiltrative lobules of cartilage with variable degree of cellularity and nuclear atypia
    • Characterized by IDH mutations
  • Chondroblastoma:
    • Arises mostly in young patients with immature skeleton
    • Epiphyseal location is characteristic
    • Islands of mononuclear cells with distinct cell borders, characteristic grooved nuclei; scattered cells may appear epithelioid
    • Chicken wire-like calcifications are characteristic
    • Harbors mutations of H3.3 (H3F3B gene) on chromosome 17
  • Osteochondromyxoma:
    • Extremely rare chondroid and osteoid matrix producing benign myxoid tumor, occurring in association with Carney complex
    • Tumor arises in the diaphysis of radius and tibia and nasal bone
    • Variably cellular tumor of polygonal bipolar to stellate cells arranged in sheets and lobules along with osteoid and chondroid matrix present in myxoid stroma
    • Lacks GRM1 upregulation and other chromosome 6 aberrations; instead harbors mutations of PRKAR1A at chromosome 17
  • Aneurysmal bone cyst:
    • Lytic expansile lesion on radiology with variable fluid levels on MRI
    • Composed of cystic blood filled spaces lined by osteoclast-like giant cells
    • Solid areas show spindle cell proliferation with blue bone formation
    • May be associated morphological finding in a number of benign and malignant bone and cartilaginous tumors
  • Giant cell tumor:
    • Arises in epiphyses of long bones in adults
    • Uniform distribution of osteoclast type giant cells among mononuclear cells
    • Shows positive staining for RUNX2, SATB2, H3.3 (G34W)
    • Excellent response to denosumab (RUNX ligand inhibitor)
Board review style question #1

A 25 year old woman presented with painful swelling of the right knee. Radiology shows a lytic lesion with sclerotic intramedullary margins in the metaphysis of proximal fibula. En bloc resection of tumor was done and microscopy showed the above picture. Which of the statements regarding this entity is true?

  1. Denosumab is a newly developed drug for nonsurgical treatment
  2. Diagnosis does not require correlation with radiology
  3. Most cases of this tumor present clinically as painless masses
  4. Presence of adjacent aneurysmal bone cyst-like areas is unlikely
  5. This tumor shows various stages of cartilaginous development
Board review style answer #1
E. This tumor shows various stages of cartilaginous development. The photomicrograph shows a tumor comprised of lobules of myxoid to chondroid appearance with adjacent mononuclear cell population and some osteoclast-like giant cells. These findings are characteristic of chondromyxoid fibroma, which is also suggested by clinical and radiological appearances. The myxochondroid lobules of chondromyxoid fibroma represent various stages of cartilaginous development, from myxoid mesenchyme to well developed hyaline cartilage. Diagnosis always requires radiological correlation, which shows characteristic eccentric lytic lesion in the metaphyseal region of long bones. Painful mass is a common clinical presentation. Adjacent aneurysmal bone cyst-like areas may be seen in up to 10% of cases. Denosumab is a RUNX ligand inhibitor, recently developed for the treatment of giant cell tumor of bone.

Comment Here

Reference: Chondromyxoid fibroma
Board review style question #2

Which of the following genetic alterations is characteristic of chondromyxoid fibroma?

  1. GRM1 upregulation
  2. H3F3B mutation
  3. IDH1 mutation
  4. PRKAR1A mutation
  5. USP6 rearrangements
Board review style answer #2
A. GRM1 upregulation. USP6 rearrangements are seen in aneurysmal bone cysts. IDH1 mutations are characteristic of chondrosarcoma. H3F3B is mutated in chondroblastoma and PRKAR1A mutations are seen in osteochondromyxoma in the setting of Carney complex.

Comment Here

Reference: Chondromyxoid fibroma
Back to top
Image 01 Image 02