Gardner fibroma, GAF

Definition

Gardner fibroma and desmoid are benign fibrous tumours occurring both sporadically and in individuals with adenomatous polyposis coli (APC). GAF may be a precursor to desmoid tumour. It is uncertain whether GAF is reactive or neoplastic.

Epidemiology

Gardner fibroma is found predominantly in children and to a lesser extent in young adults.

Clinical features

The most common sites are back/paraspinal, followed by head and neck, extremities, chest and abdomen. Patients may have one or multiple lesions.

Macroscopic appearances

GAF forms a poorly circumscribed soft tissue plaque-like mass with a rubbery cut surface. Desmoids are more spherical.

Histopathology

GAF consists of sheets of densely collagenous tissue with sparse bland spindled cells. The collagen is course and eosinophilic. The tumour margins are infiltrative. There is no cytological atypia, necrosis, nodularity or fascicle formation.

Immunohistochemistry

	b-catenin	16/251
	Cyclin-D1	25/251
	c-myc	25/251
	Vimentin	1/72
	SMA	0/72
	Muscle specific actin	0/72
	Desmin	0/72
	CD34	7/72

Differential diagnosis

Scar tissue
Fibrolipoma
Lipomatosis
Fibromatosis
Elastofibroma
Nuchal-type fibroma
Desmoid tumour

References

1 Coffin CM, Hornick JL, Zhou H, et al. Gardner fibroma: a clinicopathologic and immunohistochemical analysis of 45 patients with 57 fibromas. Am J Surg Pathol 2007; 31:410-6

2 Wehrli BM, Weiss SW, Yandow S, et al. Gardner-associated fibromas (GAF) in young patients: a distinct fibrous lesion that identifies unsuspected Gardner syndrome and risk for fibromatosis. Am J Surg Pathol 2001; 25:645-51

This page last revised 16.6.2007.