Case Study: March 2007

A 25 year old presents with proptosis and a well defined orbital mass.

The figures show the distinctive diagnostic features.

Lesional tissue is positive for CD34, BCL-2 and CD99. It is negative for everything else.


1. Describe the features seen in figures 2-3 and 4-5.

2. What is the diagnosis?

3. What is the prognosis?

4. With which tumour is there histopathological and immunophenotypic overlap?

Click to show answers

1. Pseudo-vascular spaces lined by giant cells.

2. Giant cell angiofibroma

3. Usually good prognosis. Can rarely recur locally.

4. Solitary fibrous tumour.

Dei Tos AP, Seregard S, Calonje E, Chan JK, Fletcher CD. Giant cell angiofibroma. A distinctive orbital tumor in adults.
Am J Surg Pathol. 1995 Nov;19(11):1286-93.

Guillou L, Gebhard S, Coindre JM. 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. 2000 Jul;24(7):971-9.