CLINICAL SCIENCES Technetium Tc 99m–Labeled Red Blood Cells in the Preoperative Diagnosis of Cavernous Hemangioma and Other Vascular Orbital Tumors Ennio Polito, MD; Luca Burroni, MD; Patrizia Pichierri, MD; Antonio Loffredo, MD; Angelo G. Vattimo, MD Objectives: To evaluate technetium Tc 99m (99mTc) red lacrimal gland, 1 astrocytoma, 1 ophthalmic vein throm- blood cell scintigraphy as a diagnostic tool for orbital cav- bosis, and 1 orbital varix. ernous hemangioma and to differentiate between or- bital masses on the basis of their vascularization. Conclusions: The confirmation of the preoperative di- agnosis by 99mTc red blood cell scintigraphy shows that Methods: We performed 99mTc red blood cell scintig- this technique is a reliable tool for differentiating cav- raphy on 23 patients (8 female and 15 male; mean age, ernous hemangiomas from other orbital masses (sensi- 47 years) affected by an orbital mass previously re- tivity,100%; specificity,86%) when ultrasound, CT, and vealed with computed tomography (CT) and magnetic MRI are not diagnostic. Unfortunately, 99mTc red blood resonance imaging (MRI) and suggesting cavernous he- cell scintigraphy results were positive in 1 patient with mangioma. In our diagnosis, we considered the orbital hemangiopericytoma and 1 patient with lymphan- increase delayed uptake with the typical scintigraphic pat- gioma, which showed increased uptake in the lesion on tern known as perfusion blood pool mismatch. The pa- tients underwent biopsy or surgical treatment with trans- SPET images because of the vascular nature of these tu- conjunctival cryosurgical extraction when possible. mors. Therefore, in these cases, the SPET images have to be integrated with data regarding clinical preopera- Results: Single-photon emission tomography (SPET) tive evaluation and CT scans or MRI studies. On the ba- showed intense focal uptake in the orbit corresponding sis of our study, a complete diagnostic picture, CT scans to radiologic findings in 11 patients who underwent sur- or MRI studies, and scintigraphic patterns can establish gical treatment and pathologic evaluation (9 cavernous the preoperative diagnosis of vascular orbital tumors such hemangiomas, 1 hemangiopericytoma, and 1 lymphan- as cavernous hemangioma, adult-type lymphangioma, and gioma). Clinical or histologic examination of the remain- hemangiopericytoma. ing 22 patients revealed the presence of 5 lymphoid pseu- dotumors, 2 lymphomas, 2 pleomorphic adenomas of the Arch Ophthalmol. 2005;123:1678-1683 HE CAVERNOUS HEMAN- papillary dysfunction can result from gioma is the most com- compression of the intraorbital contents mon benign orbital tumor by the hemangioma. The encapsulated na- in adults and accounts for ture of this tumor allows a progressive en- 3% to 7% of all orbital mass largement without invasion of nearby Tlesions.1 It takes the form of a clearly structures or distant metastasis. Unfortu- delineated vascular mass that contains nately, the exact diagnosis is often estab- large blood-filled spaces, which are lined lished by the pathologist after the surgi- with flattened endothelial cells and sur- cal removal of the mass. rounded by a fibrous capsule. These spaces are apparently due to dilation and thick- For editorial comment ening of the walls of the capillary loops.2,3 see page 1739 These tumors may occur anywhere in the orbital cavity, but the typical localization The differential diagnosis of a unilateral is within the muscle cone, often lateral to orbital mass that causes proptosis can be the optic nerve. Usually this neoplasm oc- difficult; possibilities may include lymphoid curs in the third to the fifth decade of life, pseudotumor, orbital varices, malignant tu- Author Affiliations: and women are affected more commonly mor, lymphoma, schwannoma, menin- Departments of Ophthalmology 4 and Neurosurgery (Drs Polito, than men. No predilection exists for race gioma, hemangiopericytoma, ossifying he- Pichierri, and Loffredo) and or ethnicity. Its common manifestation is mangioma, adult-type lymphangioma, and 5 Nuclear Medicine (Drs Burroni a slowly progressive, painless, unilateral cavernoushemangioma. Computedtomog- and Vattimo), University of proptosis. Visual acuity or field compro- raphy (CT) and magnetic resonance imag- Siena, Siena, Italy. mise, diplopia, and extraocular muscle or ing (MRI) accurately illustrate the shape, (REPRINTED) ARCH OPHTHALMOL / VOL 123, DEC 2005 WWW.ARCHOPHTHALMOL.COM 1678 ©2005 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/28/2021 A C Late Blood Pool SPET Perfusion Images B Early Blood Pool Images Figure 1. Technetium Tc 99m–labeled red blood cell scintigraphy showing a typical perfusion blood pool mismatch (A). Radionuclide angiography and early blood pool studies (B) demonstrate uptake in the normal anatomical structures. Characteristic delayed blood pool slices (C) demonstrate an intense uptake of the tracer in the left orbit. SPET indicates single-photon emission tomography. A B Figure 2. Two representative axial slices of orbit (A) and sagittal sinus (B) planes for the calculation of the asymmetry index. size, and anatomical relationship of orbital masses but are images, the signal is hyperintense to fat. With gadolin- poor indicators of their vascular nature. Nevertheless, all ium, total homogeneous enhancement occurs, but be- cavernous hemangiomas share some common character- cause blood flow through the lesion is stagnant and inde- istics on CT scans, appearing as well-defined, oval to round, pendent from the orbital vascular system, a cavernous homogeneous, and encapsulated with a density somewhat hemangioma does not fill with contrast within the first 1 greater than that of muscle.5 Furthermore, CT scans are to 2 minutes.6,7 abletoshowmicrocalcifications,sometimespresentinlong- Surgical excision with transconjunctival cryosurgical ex- standing lesions. traction is the optimal procedure for removing an orbital On MRI studies (T1-weighted images), a cavernous he- cavernous hemangioma when not located in the posterior mangioma gives off a homogeneous signal, which is isoin- third of the orbital space.8 When the tumor is located in tense to muscle and hypointense to fat. On T2-weighted the posterior and lateral third of the orbital space, a lateral (REPRINTED) ARCH OPHTHALMOL / VOL 123, DEC 2005 WWW.ARCHOPHTHALMOL.COM 1679 ©2005 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/28/2021 Table 1. Clinical Findings Patient No./ CT or MRI Histologic or Sex/Age, y (Diagnostic Hypothesis) Scintigraphic Pattern Clinical Diagnosis Size, cm 1/F/56 CT and MRI: cavernous hemangioma or meningioma Positive for angioma Cavernous hemangioma 1.6 ϫ 3 2/F/38 CT and MRI: cavernous hemangioma, hemangiopericytoma, Positive for angioma Cavernous hemangioma 1.1 ϫ 1.3 or meningioma 3/M/51 MRI: intraconal orbital mass Positive for angioma Cavernous hemangioma 2.5 ϫ 3.7 4/M/41 CT and MRI: cavernous hemangioma or angiofibroma Positive for angioma Cavernous hemangioma 1.6 ϫ 1.0 5/F/59 CT and MRI: pseudotumor or lymphoma Negative for angioma Lymphoma 6/M/32 CT and MRI: myositis Negative for angioma Lymphoid pseudotumor 7/M/35 MRI: pseudotumor Negative for angioma Lymphoid pseudotumor 8/M/45 CT and MRI: pleomorphic adenoma of lacrimal gland Negative for angioma Pleomorphic adenoma 9/M/86 CT: pseudotumor or lymphoma Negative for angioma Lymphoma 10/M/56 CT: orbital mass Positive for angioma Hemangiopericytoma 11/F/63 CT and MRI: ophthalmic vein thrombosis Negative for angioma Ophthalmic vein thrombosis 12/F/66 CT and MRI: orbital varix Negative for angioma Orbital varix 13/M/42 CT and MRI: cavernous hemangioma or angiofibroma Positive for angioma Cavernous hemangioma 2.0 ϫ 1.4 14/M/25 CT and MRI: glioma Negative for angioma Lymphoid pseudotumor 15/F/11 MRI: astrocytoma, meningioma, or hemangiopericytoma Negative for angioma Astrocytoma 16/M/46 MRI: orbital mass Positive for angioma Cavernous hemangioma 2.2 ϫ 1.2 17/F/44 CT: pseudotumor Negative for angioma Lymphoid pseudotumor 18/M/51 CT and MRI: pseudotumor Negative for angioma Lymphoid pseudotumor 19/M/43 CT and MRI: fibroangioma Positive for angioma Cavernous hemangioma 2.5 ϫ 3.0 20/M/26 MRI: cavernous hemangioma Negative for angioma Pleomorphic adenoma 21/F/76 CT: orbital mass Positive for angioma Cavernous hemangioma 2.2 ϫ 1.0 22/M/34 CT and MRI: cavernous hemangioma Positive for angioma Lymphangioma 3.0 ϫ 3.5 23/M/55 CT and MRI: orbital mass Positive for angioma Cavernous hemangioma 2.8 ϫ 2.4 Abbreviations: CT, computed tomography; MRI, magnetic resonance imaging. A B Transverse 66 67 68 Coronal 54 55 56 Sagittal 55 56 57 Figure 3. Comparison of a characteristic magnetic resonance imaging axial slice (A) and delayed single-photon emission tomogram (B) in a patient with a cavernous hemangioma of the left orbit (asymmetry index=10.71). Numbers in the lower right corners indicate the transverse, coronal, and sagittal planes. surgical approach is performed. When this surgical ap- accurate preoperative diagnosis of a cavernous heman- proach proves impossible, the patient is monitored via se- gioma or other vascular orbital tumor. rial radiographic studies approximately every 3 months.9 Tothisend,wehaveadoptedtechnetiumTc99m(99mTc)– Moreover, early and complete surgical excision of the labeled red blood cell scintigraphy as a diagnostic tool when mass is necessary in the management of a malignant vas- the diagnosis of an orbital vascular tumor (particularly a cular