Soft tissue
Fibroblastic / myofibroblastic
Gardner fibroma
Editorial Board Member: Jose G. Mantilla, M.D.
Deputy Editor-in-Chief: Borislav A. Alexiev, M.D.
Last author update: 30 September 2024
Last staff update: 30 September 2024
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PubMed Search: Gardner fibroma
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross description | Frozen section description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Molecular / cytogenetics description | Molecular / cytogenetics images | Videos | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Abrahao Machado LF. Gardner fibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuegardnerfibroma.html. Accessed November 28th, 2024.
Definition / general
- Gardner fibroma is an uncommon benign lesion characterized by dense, haphazardly arranged collagen bundles with scattered intermixed bland fibroblasts (Am J Surg Pathol 2001;25:645)
- Majority are associated with familial adenomatous polyposis (FAP), APC gene mutation or familial desmoid fibromatosis (Am J Surg Pathol 2007;31:410)
Essential features
- Unusual benign lesion composed of thick, haphazardly arranged collagen fibers and sparse fibroblastic spindle cells (Am J Surg Pathol 2001;25:645)
- Plaque-like mass in the paraspinal region or trunk of young children, teenagers and young adults (Am J Surg Pathol 2007;31:410, Am J Surg Pathol 2001;25:645)
- 70% of cases linked to FAP / Gardner syndrome (Am J Surg Pathol 2007;31:410)
- High risk for development of desmoid fibromatosis (20% of cases) (Cancer Lett 2014;353:176)
- Expression of beta catenin (nuclear) and CD34 (Am J Surg Pathol 2007;31:410)
Terminology
- Gardner associated fibroma
- Gardner type fibroma
ICD coding
- ICD-O: 8810/0 - Gardner fibroma
- ICD-11: EE6Y & XH7GT0 - other specified fibromatous disorders of skin and soft tissue & Gardner fibroma
Epidemiology
- Most often in children < 10 years (Am J Surg Pathol 2007;31:410)
- May occur in teens and young adults (Am J Surg Pathol 2007;31:410)
- No sex predilection (Am J Surg Pathol 2007;31:410, Am J Surg Pathol 2001;25:645)
Sites
- Back and paraspinal region (60%) (Am J Surg Pathol 2007;31:410)
- Also head / neck region, extremities, abdomen and chest (Am J Surg Pathol 2007;31:410, Am J Surg Pathol 2001;25:645)
Pathophysiology
- Most cases arise in patients with germline mutations in the APC tumor suppressor gene at 5q21 (Eur J Hum Genet 2015;23:715)
Etiology
- Majority of cases (70%) are associated with FAP, APC mutation or familial desmoid fibromatosis (Am J Surg Pathol 2007;31:410)
Clinical features
- Typically patients present with a painless subcutaneous mass in the back and paraspinal region, ranging in size from < 1 cm to > 10 cm (J Pediatr Hematol Oncol 2016;38:e154, Am J Surg Pathol 2007;31:410)
- Usually solitary, although multiple lesions can occur (Am J Surg Pathol 2001;25:645, Am J Surg Pathol 2007;31:410)
- Patients may have a known history of FAP / Gardner syndrome or Gardner fibroma may be the sentinel event for the diagnosis (Pediatrics 2010;126:e1599, European J Pediatr Surg Rep 2016;4:17)
Diagnosis
- Tissue sampling is the gold standard for a definitive diagnosis
- Tumor location and patient age are important hints (Am J Surg Pathol 2001;25:645)
- Diagnostic essential criteria according to the WHO classification of tumors
- Plaque-like tumor in a paraspinal location or the trunk
- Haphazardly arranged coarse collagen fibers with cracks or clefts and few bland spindle cells
- Beta catenin (nuclear) and CD34 expression
Radiology description
- Ultrasound: usually hyperechoic compared to the surrounding tissues (Radiographics 2016;36:1195)
- Computed tomography (CT): appears as a nonspecific isoattenuating soft tissue mass (Radiographics 2016;36:1195)
- Magnetic resonance imaging (MRI): plaque-like low signal intensity tumors; otherwise nonspecific (Radiographics 2016;36:1195)
- T1: low signal intensity
- T2: low signal intensity
- T1 C+ (Gd): variable
Radiology images
Images hosted on other servers:
Chest wall tumor (MRI)
Paravertebral mass (MRI)
Well defined lobulated mass in retropharynx (MRI)
Huge mass occupying the right thoracic cavity
Prognostic factors
- Gardner fibroma is benign but associated with development of desmoid fibromatosis in 20% of cases (concurrent or subsequent) (Cancer Lett 2014;353:176)
- Usually cured by excision, although occasionally may recur when incompletely excised (European J Pediatr Surg Rep 2016;4:17)
- Higher recurrence rates for concurrent or subsequent desmoid type fibromatosis (Cancer Lett 2014;353:176)
- Gardner fibroma can be an early manifestation of FAP / Gardner syndrome and familial desmoid fibromatosis (Am J Surg Pathol 2001;25:645)
Case reports
- 2 neonate boys with tumors on the chest wall and paravertebral soft tissues (European J Pediatr Surg Rep 2016;4:17)
- 4 month old child with right scapular subcutaneous nodule and 5 month old child with 2 lumbar subcutaneous nodules (Eur J Hum Genet 2015;23:715)
- 16 month old girl with mass in the retropharyngeal space (BMJ Case Rep 2018;2018:bcr2018225079)
- 18 year old woman with right thoracic cavity mass (Int J Clin Exp Pathol 2020;13:2158)
Treatment
- Simple surgical excision (European J Pediatr Surg Rep 2016;4:17)
- Children with Gardner fibroma are recommended for clinical follow up with special attention to the development of fibromatosis and colorectal tumors; their families should be investigated for FAP as well (Cancer Lett 2014;353:176, Tumori 2021;107:NP73, Pediatrics 2010;126:e1599, Am J Surg Pathol 2001;25:645)
Gross description
- Most lesions are poorly circumscribed plaque-like subcutaneous masses (Am J Surg Pathol 2007;31:410)
- Cut surface is typically rubbery white to yellow
- Size ranges from < 1 cm to > 10 cm
Frozen section description
- Frozen section examination usually demonstrates a fibrous lesion without signs of malignancy, with sparse spindle cells without nuclear atypia within a dense collagen background (Eur Ann Otorhinolaryngol Head Neck Dis 2016;133:357)
Microscopic (histologic) description
- Haphazardly arranged sheets of coarse collagen bundles separated by clefts or cracks with intervening small bland spindle cells (fibroblasts)
- Variable amounts of entrapped adjacent tissues at periphery such as adipose tissue, nerves and blood vessels (Am J Surg Pathol 2001;25:645)
- There is no fascicular or bundling architectural pattern of neoplastic cells
Microscopic (histologic) images
Contributed by Lucas F. Abrahao Machado, M.D., Ph.D.
Abundant collagen and artifactual clefting
Sheets of coarse collagen bundles
Indistinct bland spindle cells
Entrapment of adjacent tissues
Gardner fibroma with adjacent fibromatosis
Beta catenin
CD34
Cytology description
- Cytological diagnosis of benign fibroblastic tumors is difficult due to nonspecific findings, paucity of cellular component and increased amount of extracellular matrix (Cytopathology 2020;31:115)
- Fine needle aspiration cytology (FNAC) smears are generally paucicellular, showing sparse benign spindle shaped cells in a collagenous stroma
- FNAC may be helpful if taken in the clinical context, patient age and site of presentation (Cytopathology 2020;31:115)
Positive stains
- CD34 diffuse positivity (78%) (Am J Surg Pathol 2001;25:645)
- Beta catenin (nuclear) expression (64%) (Am J Surg Pathol 2007;31:410)
- Cyclin D1 and MYC (100%) (Am J Surg Pathol 2007;31:410)
Negative stains
Molecular / cytogenetics description
- Most cases arise in patients with germline mutations in the APC tumor suppressor gene (5q21) (Eur J Hum Genet 2015;23:715)
- Mutations are mostly nonsense or frameshift, resulting in a truncated protein
- Generally there is biallelic APC inactivation, which leads to loss of protein function
- Gold standard for mutation detection is direct DNA sequencing of all 15 coding exons; the methods are generally PCR based (Genet Med 2014;16:101)
- Multiplex ligation dependent probe amplification (MLPA) can be used to detect large deletions (European J Pediatr Surg Rep 2016;4:17)
Molecular / cytogenetics images
Images hosted on other servers:
Genetic findings in an infant with Gardner fibroma
MLPA showing monoallelic deletion in APC coding region
Frameshift mutation (deletion) of APC at exon15
Videos
Gardner fibroma versus nuchal type fibroma
Sample pathology report
- Paraspinal subcutaneous mass, excision:
- Gardner fibroma (see comment)
- Comment: Sections show a paucicellular lesion with dense collagen bundles with intervening clefting artifacts, bland spindle cells and focal entrapment of adipose tissue. While it follows a benign course, patients can develop desmoid fibromatosis in 20% of cases. Gardner fibroma is strongly associated with FAP; therefore, close clinical investigation, screening of family members and genetic testing / counseling are recommended.
Differential diagnosis
- Nuchal type fibroma:
- Very similar morphology
- Often shows a localized proliferation of small nerves
- Negative for beta catenin
- Not associated with FAP / Gardner syndrome
- More common in adults
- Desmoplastic fibroblastoma:
- Also has dense collagen but more homogenous
- Prominent stellate fibroblasts with amphophilic cytoplasm
- Elastofibroma:
- Prominent abnormal eosinophilic elastic fibers
- Mostly arises in the deep soft tissue of the lower scapula region
- Often bilateral
- Almost exclusively in the elderly
- Fibromatosis:
- More cellular, with fascicular architecture
- Usually large deep lesion
- Often with infiltration of skeletal muscle fibers
- Hypocellular areas resembling Gardner fibroma may be present
Additional references
Board review style question #1
A 1 year old baby whose father is known to have familial adenomatous polyposis (FAP) presented with a painless, slow growing mass measuring 2 cm in the upper dorsal paravertebral region. What is the diagnosis?
- Elastofibroma
- Gardner fibroma
- Neurofibroma
- Nuchal type fibroma
Board review style answer #1
B. Gardner fibroma. The majority of patients (70%) with Gardner fibroma have a history of familial adenomatous polyposis (FAP) and it can be an early manifestation of the disorder. Answers A, C and D are incorrect because there is no known association of elastofibroma, neurofibroma or nuchal type fibroma with FAP.
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Board review style question #2
Patients with Gardner fibroma have an increased risk of developing which of the following soft tissue tumors?
- Dermatofibrosarcoma protuberans
- Desmoid fibromatosis
- Juvenile xanthogranuloma
- Malignant peripheral neural sheath tumor
Board review style answer #2
B. Desmoid fibromatosis. Gardner fibroma is associated with concurrent or subsequent development of desmoid fibromatosis in ~20% of cases. Answers A, C and D are incorrect because patients with Gardner fibroma do not have an increased risk of developing dermatofibrosarcoma protuberans, juvenile xanthogranuloma or malignant peripheral neural sheath tumor.
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