Orbital cavernous haemangiomas: immunohistochemical study of proliferative capacity, vascular differentiation and
Aanchal Gupta1, Venkatesh C Prabhakaran, Tom Dodd
1South Australian Institute of Ophthalmology and Visual Sciences, University of Adelaide, Adelaide, South Australia. aanchal09@gmail.com
Background/Aims:
Immunohistochemical characterisation of orbital cavernous haemangiomas (CHs) with respect to proliferative capacity, hormone receptor status and vascular differentiation.
Methods:
Eleven cases of orbital CHs were reviewed. Immunohistochemical stains for Mib-1, proliferating cell nuclear antigen (PCNA), Bcl-2, estrogen and progesterone receptors (ER & PR), CD31, D2-40, and VEGF were investigated in 11 specimens.
Results:
Immunohistochemical staining revealed positivity for PCNA in ten of the 11 cases (91%). Bcl-2 was positive in 8 cases (73%). VEGF and PR were each weakly positive in 3 cases. All cases were negative for Mib-1, ER and D2-40. The staining was localized around the endothelium.
Conclusion:
This is the first study to characterise in detail the immunohistochemical features of orbital CHs. The proliferative markers PCNA and Mib-1 show discordant expression in these lesions and the expression of PCNA and Bcl-2 in the absence of Mib-1 is indicative of low proliferative potential. Small subsets of these tumors express PR and VEGF, which may partly explain the proliferative capacity of some orbital CHs.
