Giant cell angiofibroma, GCA

Definition

A benign tumour containing multinucleate giant cells and angiectatic spaces. This entity is possibly closely related to solitary fibrous tumour, with one paper describing cases of intermediate appearance⁴.

Clinical features

Usually occurs in the middle-aged, most commonly in the orbit or eyelid of males and in extra-orbital sites in females. It may occur elsewhere in the head^5,7 and neck⁴, mediastinum³, retroperitoneum⁴, back⁴, axilla⁷, vulva⁴ and inguinal region^6,7.

Macroscopic appearances

The lesion is circumscribed and variably encapsulated⁴. The cut surface is yellowish-white and there may be haemorrhage and cystic change⁴.

Histopathology

Cellular areas consist of bland round to spindle cells, along with multinucleate giant cells; the nuclei are central or in a floret arrangement^1,4. The giant cells often line pseudovascular spaces. There are well-formed thick-walled small to medium size vessels. There may be staghorn pericytomatous vascular spaces, similar to those seen in solitary fibrous tumour⁴. The stroma varies from collagenous to myxoid. One cases contained islands of adipocytes, creating an overlap with lipomatous hemangiopericytoma⁴.

Immunohistochemistry

	CD34	positive0,1,2, 10/10 (diffuse positivity in all cases)4, 2/25, 1/15, 4/47
	CD99	positive0, 10/10 (most cases diffuse strong positivity)4
	bcl-2	variable0, 8/10 (variable extent and intensity)4, 1/15
	vimentin	positive1,2, 10/10 (diffuse positivity in all cases)4, 2/25, 4/47
	Factor VIIIRA	0/25
	Desmin	0/25, 0/104, 0/15
	SMA	0/25, 4/10 (variable extent)4, 0/15
	Muscle-specific actin	0/104, 0/15
	Myoglobin	0/25
	S-100	0/25, 3/10 (focal positivity)4, 0/15, 1/4 (focal positivity)7
	GFAP	1/4 (focal positivity)7
	CD15 (LeuM1)	0/25
	Lysozyme	0/25
	Alpha-1-antitrypsin	0/25
	AE1/3	0/25
	Cam5.2	0/25
	MNF116	1/10 (focal strong positivity)4
	EMA	2/10 (focal weak positivity)4
	CD31	0/104
	CD117	0/104
	inhibin	0/104

Ultrastructure

Cells show fibroblastic features. In one case, they showed Schwannian features⁷.

Differential diagnosis

• Solitary fibrous tumour

If extra-orbital:

• Giant cell fibroblastoma

• Synovial sarcoma

• Fibrosarcoma

• MFH

• Deep fibrous histiocytoma

• Haemangiopericytoma

• Schwannoma

• Various neoplasms containing osteoclast-like histiocytes: the giant cells in GCA resemble the mononuclear component and are positive for CD34, CD99, sometimes for bcl-2, but are negative for CD68.

Prognosis

This tumour is benign, with rare local recurrences.

References

⁰World Health Organization Classification of Tumours, Tumours of Soft Tissues and Bone, IARC Press 2002.

¹Dei Tos, A. P., S. Seregard, et al. (1995). "Giant cell angiofibroma. A distinctive orbital tumor in adults." Am J Surg Pathol 19(11): 1286-93.

²Hayashi, N., G. Borodic, et al. (1999). "Giant cell angiofibroma of the orbit and eyelid." Ophthalmology 106(6): 1223-9.

³Fukunaga, M. and S. Ushigome (1998). "Giant cell angiofibroma of the mediastinum." Histopathology 32(2): 187-9.

⁴Guillou, L., S. Gebhard, et al. (2000). "Orbital and extraorbital giant cell angiofibroma: a giant cell-rich variant of solitary fibrous tumor? Clinicopathologic and immunohistochemical analysis of a series in favor of a unifying concept." Am J Surg Pathol 24(7): 971-9.

⁵Mikami, Y., M. Shimizu, et al. (1997). "Extraorbital giant cell angiofibromas." Mod Pathol 10(11): 1082-7.

⁶Sigel, J. E., C. Fisher, et al. (2000). "Giant cell angiofibroma of the inguinal region." Ann Diagn Pathol 4(4): 240-4.

⁷Thomas, R., S. S. Banerjee, et al. (2001). "A study of four cases of extra-orbital giant cell angiofibroma with documentation of some unusual features." Histopathology 39(4): 390-6.

This page last revised 1.7.2004.

©SMUHT/PW Bishop