Orbital Cellular Epithelioid Hemangioma

Abstract

Purpose: To report a case of orbital cellular epithelioid hemangioma (EH) in which FOSB and CAMTA1 immunostains were used to detect a cytogenetic rearrangement as an adjunctive tool in diagnosis.

Methods: Case report.

Results: A patient with a history of prior ligation of a presumed orbital varix presented with recurrent proptosis. Imaging revealed a highly vascular right orbital mass. Microscopic examination revealed a circumscribed neoplasm composed of plump epithelioid endothelial cells with copious mildly eosinophilic cytoplasm and relatively uniform vesicular nuclei. To aid in diagnosis, immunostains for FOSB and CAMTA1 were performed to detect corresponding cytogenetic rearrangements. The presence of multifocal nuclear positivity for FOSB, indicating FOSB genetic rearrangement, and negativity for CAMTA1 were considered reassuring features against a diagnosis of a malignant epithelioid hemangioendothelioma (EHE), supporting a diagnosis of benign cellular EH.

Conclusions: This case report demonstrates that the use of immunohistochemical stains to detect cytogenetic rearrangements may aid in the distinction between benign EH and malignant EHE. It also reminds providers of the clinical and histopathologic features of this lesion, which occurs rarely in the orbit, and helps clarify the evolving nomenclature surrounding epithelioid hemangioma.

Keywords: Angiolymphoid hyperplasia with eosinophilia; Cytogenetics; Epithelioid hemangioma.

Fig. 1

a Clinical photograph demonstrating right-sided proptosis and hypoglobus. b Orbital CT with contrast revealing an ovoid, peripherally enhancing mass at the superomedial aspect of the right orbit (yellow arrow). c Orbital MRI with contrast demonstrating a homogeneous, intensely enhancing mass within the right superomedial orbit measuring 2.2 × 1.4 × 1.3 cm. d Arterial angiography demonstrating a hypervascular mass arising from the branches of the ophthalmic artery (blue arrow).

Fig. 2

a Low magnification image of the resected specimen, noted to be a circumscribed but unencapsulated neoplasm. b, c Higher magnification images reveal a neoplasm composed of plump epithelioid endothelial cells with copious palely eosinophilic cytoplasm and relatively uniform vesicular nuclei. In many areas, one can appreciate a well-developed vasoformative architecture. d In the seemingly more solid areas, staining for SMA helps to highlight the presence of well-formed, closely packed vessels. Hematoxylin and eosin: ×1.25 (a), ×20 (b), ×40 (c). d Smooth muscle actin: ×20.

Fig. 3

a In addition to the plump epithelioid endothelial cells (blue arrow), pericytes with round, dark nuclei and clear cytoplasm can be seen lining the vascular channels in close proximity to the endothelial cells (yellow arrow). b, c The cells lining the vascular channels stained positively with Factor VIII and CD34. d Multifocal nuclear positivity for FOSB was present, indicating an FOSB gene rearrangement, while an immunostain for CAMTA1 was negative (not pictured). a Hematoxylin and eosin: ×40. b Factor VIII: X40. c CD34: ×40. d FOSB: ×40.