- Email: [email protected]
Supraciliary Hemangiopericytoma
Supraciliary H emangio pericyto ma HARRY H. BROWN, MD,t· 2 MICHAEL C. BRODSKY, MD, 1 KATHRYN HEMBREE, MD, 1 ROBERT E. MRAK, MD, PhD 2•3
Abstract: A 10-year-old black girl complaining of pain and decreased vision in the left eye was found to have a smoothly elevated ciliochoroidal mass in volving the superonasal quadrant of the left eye. The mass appeared circum scribed and uniformly dense by computed tomography. The tumor was hyper intense to vitreous and cerebral white matter on T1-weighted magnetic resonance imaging but was hypointense to vitreous and hyperintense to white matter on T2-weighted magnetic resonance imaging. Results of gross examination of the enucleated eye showed a sharply circumscribed, tan, intraocular mass arising equatorially. Results of histopathologic examination showed a well-vascularized spindle cell proliferation with a sinusoidal pattern characteristic of hemangiop ericytoma. This is the third reported case of intraocular hemangiopericytoma and the first in a pediatric patient. Ophthalmology 1991 ; 98:378-382
Hemangiopericytomas are soft tissue tumors of vascular origin that exhibit variable and unpredictable behavior. 1 Although they most often arise in the lower extremities and retroperitoneum, the orbit is a relatively common primary site. 2 In contrast, there are only two reported cases of intraocular hemangiopericytoma. 3•4 In both cases, the tumors developed within the uveal tract of adult women. We report the clinical, radiographic, and light and electron microscopic findings of an additional case of intraocular hemangiopericytoma, contained within the supraciliary and suprachoroidal spaces, in a 10-year-old girl.
CASE REPORT A 10-year-old black girl was referred to the Arkansas Children's Hospital for evaluation of a superiorly based ciliary body mass. She had experienced transient episodes of pain in the left eye for 3 months before presentation. In the I month preceding Originally received: October 1, 1990. Revision accepted: November 26, 1990. ' Department of Ophthalmology, University of Arkansas for Medical Sci ences, Little Rock. 2 Department of Pathology, University of Arkansas for Medical Sciences, Little Rock. 3 John R. McClellan Veterans Administration Hospital, Little Rock. Reprint requests to Harry H. Brown, MD, UAMS Department of Pathology Slot 517, 4301 W Markham, Little Rock, AR 72205.
378
presentation, the superior episcleral vessels had become markedly congested. She had no other health problems. On examination, visual acuity was 20/20 in the right eye and counting fingers at 6 feet in the left. The left pupil reacted slug gishly to direct light and there was a left afferent pupillary defect. Results of external examination showed marked dilatation of superonasal episcleral vessels in the left eye. On biomicroscopic examination, the peripheral iris was bowed anteriorly superona sally. Rubeosis was not present. The lens was clear and normally positioned. Intraocular pressure was 12 mmHg in the left eye. Results of ophthalmoscopic examination of the left eye through a dilated pupil showed a large, dome-shaped, smooth-surfaced mass involving the superior and superonasal ciliary body (Fig 1). The overlying ciliary epithelium and peripheral retina con tained multiple, transparent, cystic spaces. The vitreous was clear. A low-lying serous retinal detachment extended posteriorly and inferiorly from the mass, involving the macula. The tumor readily transilluminated using a transscleral transillumination technique. High-resolution axial computed tomography showed a solid, round, homogeneous ciliochoroidal mass (Fig 2, top left). B scan ultrasonography demonstrated a solid, circumscribed, dome-shaped mass (Fig 2, top right). Magnetic resonance im aging showed the mass to be of uniform signal intensity on both T 1- and Tr weighted images. On T 1-weighted imaging, the mass was markedly hyperintense to vitreous and mildly hyperintense to cerebral cortex and white matter (Fig 2, bottom left). On T2 weighted imaging, the mass was hypointense to vitreous, isoin tense to cerebral gray matter, and hyperintense to white matter (Fig 2, bottom right). Extraocular extension was not identified in any imaging study. Systemic examination including bone and liver/spleen scans failed to demonstrate metastatic disease. Because of the possi
BROWN et al
•
SUPRACILIARY HEMANGIOPERICYTOMA
bility of malignancy in an eye with severely decreased vision, the left eye was enucleated.
RESULTS
Fig 1. A dome-shaped ciliary body mass is seen through the dilated pupil.
The enucleated left eye measured 24.0 mm (antero posterior) X 23.0 mm (vertical) X 24.0 mm (horizontal). A slight bulge of the superior sclera at and anterior to the equator was noted, but no extrascleral tumor extension was detected, either directly or via the superior vortex veins. The intraocular mass was readily seen through the dilated pupil on transillumination ofthe globe. The unfixed eye was opened vertically in an antero posterior plane nasal to the optic nerve, revealing a well circumscribed, tan, dome-shaped mass at the equator of the globe (Fig 3). The 12.0 mm (anteroposterior) X 9.0 mm (height) mass compressed and displaced the contig uous ciliary body and choroid internally. Cystic degen eration of the ciliary epithelium and retina overlying the mass was evident. The cut surface of the tumor bulged slightly above the plane of section. No cystic degeneration, necrosis, or hemorrhage was present within the tumor.
Fig 2. Computed tomo graphic scan (top left) dem onstrates a circumscribed, uniformly homogeneous mass involving the ciliary body and choroid. B-scan ul trasonography (top right) also highlights the smooth cir cumscription of the tumor. T 1-weighted (TR = 800, TE = 20) MR image (bottom left) shows the mass to be hyper intense to vitreous and cere bral white matter. On T 2 weighted (MPGR/20, TR = 500, TE = 30) MR imag ing (bottom right) the tumor is hypointense to vitreous but hyperintense to cerebral white matter.
379
OPHTHALMOLOGY
•
MARCH 1991
Fig 3. A smooth-surfaced, sharply circumscribed mass is present at the equator of the globe, causing a serous retinal detachment.
Results of light microscopic examination of the eye showed a sharply demarcated, nonencapsulated tumor within the supraciliary and suprachoroidal spaces, dis placing the uveal tissue toward the center of the eye (Fig 4). Dilated vascular spaces were prominent in the sclera and episclera adjacent to the intraocular mass. The ma jority of the tumor demonstrated a sinusoidal pattern with tumor cells outlining irregular, endothelial-lined vascular spaces (Fig 5). Elsewhere, there was a more solid config uration, with only inconspicuous vascular clefts present. Tumor cells were arranged in syncytial cords and sheets, without distinct cytoplasmic borders. Nuclei were plump, vesicular, and mildly pleomorphic, containing small cen trally placed nucleoli and occasionally exhibiting intra nuclear cytoplasmic invaginations; two mitotic figures were identified in 40 high power fields (Fig 6). Occasional aggregates of chronic inflammatory cells were present within the tumor. The retina and ciliary epithelium over lying the tumor were cystically degenerated, and drusen formation was apparent along Bruch's membrane. Pos terior and inferior to the tumor there was a serous retinal detachment, with degeneration ofthe outer retinal layers. Immunohistochemical studies performed on formalin fixed, paraffin-embedded tissue showed positivity within 380
•
VOLUME 98
•
NUMBER 3
Fig 4. The circumscribed tumor (HP) occupies the supraciliary space, displacing the ciliary body (CB) anteriorly (arrows). Notice the dilated scleral and episcleral vessels (asterisks) (hematoxylin and eosin; original magnification, X 10).
tumor cells for vimentin, but no evidence ofS-100 protein or desmin could be demonstrated. Ultrastructurally, tumor cells contained variable num bers of mitochondria but were otherwise sparsely popu lated by rough endoplasmic reticulum, Golgi bodies, and rare small electron-dense granules. Rare cells contained few aggregates of intracytoplasmic filaments, lacking fu siform densities characteristic of smooth muscle cells. In complete segments of basal lamina occasionally outlined individual cells, and there also were irregular extracellular clumps of similar basal lamina-like material (Fig 7). Tu mor cells adjacent to endothelial cells were separated from them by a basal lamina, which in areas was reduplicated (Fig 8).
DISCUSSION Hemangiopericytomas were first described by Stout and Murray 1 in 1942 as tumors arising from pericytes, those mesenchymal cells that incompletely surround the en dothelium of the capillary. Hemangiopericytomas are
BROWN et al
•
SUPRACILIARY HEMANGIOPERICYTOMA
Fig 5. Variably sized, irregularly shaped vascular spaces are surrounded by plump spindle cells with indistinct cellular borders (hematoxylin and eosin; original magnification, X40).
Fig 7. Deposits of irregular, thickened basal lamina (asterisks) are present between tumor cells, which have a thin , discontinuous basal lamina (ar rows) (bar = 5 !Lm).
Fig 6. Tumor cell nuclei have a smooth chromatin pattern with small but distinct nucleoli. Notice the mitotic figure centrally (arrow) (hema toxylin and eosin; original magnification, X I00).
Fig 8. A vascular space containing an erythrocyte (E) and lined by an endothelial cell is separated from the tumor cell by reduplicated basal lamina (arrows) (bar = 5 !Lm).
uncommo n, and they most often occur in the retroperi toneum and lower extremities of adults as slowly growing 2 circumscribed masses. Due to their rich vascularity, tu mors may cause telangiectasias and/or varicosities of the overlying skin. The malignant potential of hemangiopericytomas is variable and unpredictable. Metastatic disease occurs in anywhere from 12 to 56% of patients and usually develops within 5 years of initial diagnosis, although late metastases are not rare. 2 Lungs and bone are the most common met astatic sites of involvement. Proposed histologic criteria portending a more aggressive course include the presence of 4 or more mitotic figures per 10 high-power fields, in creased cellularity, nuclear pleomorphism, and foci of 2 hemorrhage and necrosis. However, histologically "be nign" hemangiopericytoma has resulted in death due to metastatic spread. 5 Hemangiopericytoma-like patterns may be seen focally in other tumors, such as fibrous histiocytoma, synovial sarcoma, and mesenchymal chondrosarcoma, but in most
entities distin cases other characteristic features of these 2 guish them from hemangiopericytoma. Intraocular tu mors that may demonstrate a prominent vascular pattern include leiomyoma and schwannoma; imuunohisto chemical studies for the presence of smooth muscle and neural antigens, respectively, can aid in differentiating these neoplasms. 6 Electron microscopy may be necessary to confirm the diagnosis. Hemangiopericytoma tumor cells are charac terized by organelle-poor cytoplasm with elongate cyto plasmic processes, plasmalemma! pinocytotic vesicles, external basal lamina, usually incompletely encircling cells and forming extracellular clumps, and reduplicated basal lamina separating tumor cells from capillary endothelium. Orbital hemangiopericytomas have occurred with on enough frequency to elicit several series and reviews 10 57 9 optic a, conjunctiv the of the subject. • - Involvement 12 nerve, 11 and lacrimal sac also has been reported. Intra ocular hemangiopericytoma, however, has only been re ported twice. 3·4 In each case, the tumor was a well-cir 381
OPHTHALMOLOGY
•
MARCH 1991
cumscribed mass arising within uveal tissue of an adult female: one, a sessile, dome-shaped tumor of the mid peripheral choroid, 3 and the other a pedunculated tumor originating in the stroma of the pars plicata of the ciliary body. 4 In the current case, the hemangiopericytoma ex panded within the supraciliary and suprachoroidal spaces, displacing both the ciliary body and choroid toward the vitreous cavity. Telangiectasia of the overlying retinal vessels3 and prominent episcleral vessels4 were noted in association with the tumors in previous reports, and marked dilatation of episcleral vessels was a significant clinical and histopathologic finding in our case. Promi nence ofepiscleral vessels external to an intraocular tumor has been judged to be "a particularly important sign of ciliary body melanoma;" 13 hemangiopericytoma must now also be considered when prominent vessels are pres ent overlying an intraocular mass. Masses involving the ciliary body/choroid in children are distinctly uncommon. Reported diagnoses include leiomyoma, 13 melanoma, 14 hemangioma, 15 ·16 juvenile xanthogranuloma, 17 mesectodermal leiomyoma, 18 ade noma of the nonpigmented ciliary epithelium, 19 neuro fibroma, 20 neurilemoma, 21 and medulloepithelioma. 22
Since proper management for these conditions varies from corticosteroid therapy in cases of juvenile xanthogranu loma to enucleation or radiation therapy for melanoma, accurate clinical diagnosis is imperative. Magnetic resonance imaging has been judged superior to computed tomography in the detection and differential diagnosis of intraocular tumors. 23 ·24 Because of the small numbers oftumors evaluated other than melanoma, cor relation of signal characteristics with specific tumor types is not yet possible. However, due to the paramagnetic properties of melanin, melanotic melanomas have distinct signal characteristics on magnetic resonance imag ing. 23 - 25 Melanin contains stable free radicals that are paramagnetic, causing intraocular melanotic melanomas generally to appear hyperintense to vitreous on T 1 weighted MR images and hypointense to vitreous on T 2 weighted images. Amelanotic melanomas are only slightly hyperintense or isointense to vitreous on T 1-weighted im aging, and hypointense to vitreous on T 2-weighted im aging.24 Magnetic resonance imaging was helpful in distin guishing our patient's tumor from ciliary body melanoma. Although the MR signal characteristics of the tumor when compared with vitreous were not inconsistent with a di agnosis of melanoma, when compared with brain they were different from the usual pattern of signals described for intracerebral melanoma, where the tumor generally is hyperintense to white matter on T 1-weighted imaging and hypointense to white matter on Trweighted imaging. 25 In our case, the intraocular tumor was slightly hyperin tense to white matter on T 1-weighted images but signifi cantly hyperintense on T rweighted imaging. Comparison of tumor signals not only to vitreous but also to brain may prove beneficial in the clinical differential diagnosis of intraocular tumors. The pattern of MR images in our patient's tumor may provide an important clue to the clinical recognition of future cases of intraocular heman giopericytoma. 382
•
VOLUME 98
•
NUMBER 3
REFERENCES 1. Stout AP, Murray MR. Hemangiopericytoma: a vascular tumor featuring Zimmermann's pericytes. Ann Surg 1942; 116:26-33. 2. Enzinger FM, Weiss SW. Soft Tissue Tumors, 2nd ed. St. Louis: CV Mosby, 1988; 596-613. 3. Papale JJ, Frederick AR, Albert OM. Intraocular hemangiopericytoma. Arch Ophthalmol 1983; 101:1409-11. 4. Gieser SC, Hufnagel TJ, Jaros PA, et al. Hemangiopericytoma of the ciliary body. Arch Ophthalmol1988; 106:1269-72. 5. Henderson JW, Farrow GM. Primary orbital hemangiopericytoma: an aggressive and potentially malignant neoplasm. Arch Ophthalmol1978; 96:666-73. 6. Enzinger FM, Weiss SW. Soft Tissue Tumors, 2nd ed. St. Louis: CV Mosby, 1988; 83-101. 7. Brown ON, MacCarty CS, Soule EH. Orbital hemangiopericytoma: review of the literature and report of four cases. J Neurosurg 1965; 22:354-61. 8. Jakobiec FA, Howard GM, Jones IS, Wolff M. Hemangiopericytoma of the orbit. Am J Ophthalmol1974; 78:816-34. 9. Croxatto JO, Font RL. Hemangiopericytoma of the orbit: a clinico pathologic study of 30 cases. Hum Pathol1982; 13:210-8. 10. Grossniklaus HE, Green WR, Wolff SM, Iliff NT. Hemangiopericytoma of the conjunctiva: two cases. Ophthalmology 1986; 93:265-7. 11. Boniuk M, Messmer EP, Font RL. Hemangiopericytoma of the menin ges of the optic nerve. A clinicopathologic report including electron microscopic observations. Ophthalmology 1985; 92:1780-7. 12. Carnevali L, Trimarchi F, Rosso R, Stringa M. Haemangiopericytorna of the lacrimal sac: a case report. Br J Ophthalrnol1988; 72:782-5. 13. Green WR. The uveal tract. In: Spencer WH, ed. Ophthalmic Pathology: An Atlas and Textbook, 3rd ed., Vol. 3. Philadelphia: WB Saunders, 1986; 1352-2072. 14. Leonard BC, Shields JA, McDonald PR. Malignant melanomas of the uveal tract in children and young adults. Can J Ophthalmol 1975; 10: 441-9. 15. Jones IS, Cleasby GW. Hemangioma of the choroid: a clinicopathologic analysis. Am J Ophthalmol1959; 48:612-28. 16. Witschel H, Font RL. Hemangioma of the choroid: a clinicopathologic study of 71 cases and a review of the literature. Surv Ophthalmol 1976; 20:415-31. 17. Zimmerman LE. Ocular lesions of juvenile xanthogranuloma: nevo xanthoendothelioma. Trans Am Acad Ophthalmol Otolaryngol1965; 69:412-42. 18. Shields JA, Shields CL, Eagle RC Jr. Mesectodermal leiomyoma of the ciliary body managed by partial lamellar iridocyclochoroidectomy. Ophthalmology 1989; 96:1369-76. 19. Patrinely JR, Font RL, Campbell RJ, Robertson OM. Hamartomatous adenoma of the nonpigmented ciliary epithelium arising in iris-ciliary body coloboma. Light and electron microscopic observations. Oph thalmology 1983; 90:1540-7. 20. Nicholson DH, Green WR. Pediatric Ocular Tumors. New York: Masson USA, 1981; 87-95. 21. Vannas S, Raitta C, Tarkkanen A. Neurilemmoma of the choroid in Recklinghausen's disease. Acta Ophthalmol Suppl 1974; 123:126 33. 22. Broughton WL, Zimmerman LE. A clinicopathologic study of 56 cases of intraocular medulloepitheliomas. Am J Ophthalmol 1978; 85:407 18. 23. Mafee MF, Peyman GA, Peace JH, et al. Magnetic resonance imaging in the evaluation and differentiation of uveal melanoma. Ophthalmology 1987; 94:341-8. 24. Peyster RG, Augsburger JJ, Shields JA, et al. Intraocular tumors: evaluation with MR imaging. Radiology 1988; 168:773-9. 25. Woodruff WW Jr, Djang WT, Mclendon RE, et al. Intracerebral ma lignant melanoma: high-field-strength MR imaging. Radiology 1987; 165:209-13.
Abstract: A 10-year-old black girl complaining of pain and decreased vision in the left eye was found to have a smoothly elevated ciliochoroidal mass in volving the superonasal quadrant of the left eye. The mass appeared circum scribed and uniformly dense by computed tomography. The tumor was hyper intense to vitreous and cerebral white matter on T1-weighted magnetic resonance imaging but was hypointense to vitreous and hyperintense to white matter on T2-weighted magnetic resonance imaging. Results of gross examination of the enucleated eye showed a sharply circumscribed, tan, intraocular mass arising equatorially. Results of histopathologic examination showed a well-vascularized spindle cell proliferation with a sinusoidal pattern characteristic of hemangiop ericytoma. This is the third reported case of intraocular hemangiopericytoma and the first in a pediatric patient. Ophthalmology 1991 ; 98:378-382
Hemangiopericytomas are soft tissue tumors of vascular origin that exhibit variable and unpredictable behavior. 1 Although they most often arise in the lower extremities and retroperitoneum, the orbit is a relatively common primary site. 2 In contrast, there are only two reported cases of intraocular hemangiopericytoma. 3•4 In both cases, the tumors developed within the uveal tract of adult women. We report the clinical, radiographic, and light and electron microscopic findings of an additional case of intraocular hemangiopericytoma, contained within the supraciliary and suprachoroidal spaces, in a 10-year-old girl.
CASE REPORT A 10-year-old black girl was referred to the Arkansas Children's Hospital for evaluation of a superiorly based ciliary body mass. She had experienced transient episodes of pain in the left eye for 3 months before presentation. In the I month preceding Originally received: October 1, 1990. Revision accepted: November 26, 1990. ' Department of Ophthalmology, University of Arkansas for Medical Sci ences, Little Rock. 2 Department of Pathology, University of Arkansas for Medical Sciences, Little Rock. 3 John R. McClellan Veterans Administration Hospital, Little Rock. Reprint requests to Harry H. Brown, MD, UAMS Department of Pathology Slot 517, 4301 W Markham, Little Rock, AR 72205.
378
presentation, the superior episcleral vessels had become markedly congested. She had no other health problems. On examination, visual acuity was 20/20 in the right eye and counting fingers at 6 feet in the left. The left pupil reacted slug gishly to direct light and there was a left afferent pupillary defect. Results of external examination showed marked dilatation of superonasal episcleral vessels in the left eye. On biomicroscopic examination, the peripheral iris was bowed anteriorly superona sally. Rubeosis was not present. The lens was clear and normally positioned. Intraocular pressure was 12 mmHg in the left eye. Results of ophthalmoscopic examination of the left eye through a dilated pupil showed a large, dome-shaped, smooth-surfaced mass involving the superior and superonasal ciliary body (Fig 1). The overlying ciliary epithelium and peripheral retina con tained multiple, transparent, cystic spaces. The vitreous was clear. A low-lying serous retinal detachment extended posteriorly and inferiorly from the mass, involving the macula. The tumor readily transilluminated using a transscleral transillumination technique. High-resolution axial computed tomography showed a solid, round, homogeneous ciliochoroidal mass (Fig 2, top left). B scan ultrasonography demonstrated a solid, circumscribed, dome-shaped mass (Fig 2, top right). Magnetic resonance im aging showed the mass to be of uniform signal intensity on both T 1- and Tr weighted images. On T 1-weighted imaging, the mass was markedly hyperintense to vitreous and mildly hyperintense to cerebral cortex and white matter (Fig 2, bottom left). On T2 weighted imaging, the mass was hypointense to vitreous, isoin tense to cerebral gray matter, and hyperintense to white matter (Fig 2, bottom right). Extraocular extension was not identified in any imaging study. Systemic examination including bone and liver/spleen scans failed to demonstrate metastatic disease. Because of the possi
BROWN et al
•
SUPRACILIARY HEMANGIOPERICYTOMA
bility of malignancy in an eye with severely decreased vision, the left eye was enucleated.
RESULTS
Fig 1. A dome-shaped ciliary body mass is seen through the dilated pupil.
The enucleated left eye measured 24.0 mm (antero posterior) X 23.0 mm (vertical) X 24.0 mm (horizontal). A slight bulge of the superior sclera at and anterior to the equator was noted, but no extrascleral tumor extension was detected, either directly or via the superior vortex veins. The intraocular mass was readily seen through the dilated pupil on transillumination ofthe globe. The unfixed eye was opened vertically in an antero posterior plane nasal to the optic nerve, revealing a well circumscribed, tan, dome-shaped mass at the equator of the globe (Fig 3). The 12.0 mm (anteroposterior) X 9.0 mm (height) mass compressed and displaced the contig uous ciliary body and choroid internally. Cystic degen eration of the ciliary epithelium and retina overlying the mass was evident. The cut surface of the tumor bulged slightly above the plane of section. No cystic degeneration, necrosis, or hemorrhage was present within the tumor.
Fig 2. Computed tomo graphic scan (top left) dem onstrates a circumscribed, uniformly homogeneous mass involving the ciliary body and choroid. B-scan ul trasonography (top right) also highlights the smooth cir cumscription of the tumor. T 1-weighted (TR = 800, TE = 20) MR image (bottom left) shows the mass to be hyper intense to vitreous and cere bral white matter. On T 2 weighted (MPGR/20, TR = 500, TE = 30) MR imag ing (bottom right) the tumor is hypointense to vitreous but hyperintense to cerebral white matter.
379
OPHTHALMOLOGY
•
MARCH 1991
Fig 3. A smooth-surfaced, sharply circumscribed mass is present at the equator of the globe, causing a serous retinal detachment.
Results of light microscopic examination of the eye showed a sharply demarcated, nonencapsulated tumor within the supraciliary and suprachoroidal spaces, dis placing the uveal tissue toward the center of the eye (Fig 4). Dilated vascular spaces were prominent in the sclera and episclera adjacent to the intraocular mass. The ma jority of the tumor demonstrated a sinusoidal pattern with tumor cells outlining irregular, endothelial-lined vascular spaces (Fig 5). Elsewhere, there was a more solid config uration, with only inconspicuous vascular clefts present. Tumor cells were arranged in syncytial cords and sheets, without distinct cytoplasmic borders. Nuclei were plump, vesicular, and mildly pleomorphic, containing small cen trally placed nucleoli and occasionally exhibiting intra nuclear cytoplasmic invaginations; two mitotic figures were identified in 40 high power fields (Fig 6). Occasional aggregates of chronic inflammatory cells were present within the tumor. The retina and ciliary epithelium over lying the tumor were cystically degenerated, and drusen formation was apparent along Bruch's membrane. Pos terior and inferior to the tumor there was a serous retinal detachment, with degeneration ofthe outer retinal layers. Immunohistochemical studies performed on formalin fixed, paraffin-embedded tissue showed positivity within 380
•
VOLUME 98
•
NUMBER 3
Fig 4. The circumscribed tumor (HP) occupies the supraciliary space, displacing the ciliary body (CB) anteriorly (arrows). Notice the dilated scleral and episcleral vessels (asterisks) (hematoxylin and eosin; original magnification, X 10).
tumor cells for vimentin, but no evidence ofS-100 protein or desmin could be demonstrated. Ultrastructurally, tumor cells contained variable num bers of mitochondria but were otherwise sparsely popu lated by rough endoplasmic reticulum, Golgi bodies, and rare small electron-dense granules. Rare cells contained few aggregates of intracytoplasmic filaments, lacking fu siform densities characteristic of smooth muscle cells. In complete segments of basal lamina occasionally outlined individual cells, and there also were irregular extracellular clumps of similar basal lamina-like material (Fig 7). Tu mor cells adjacent to endothelial cells were separated from them by a basal lamina, which in areas was reduplicated (Fig 8).
DISCUSSION Hemangiopericytomas were first described by Stout and Murray 1 in 1942 as tumors arising from pericytes, those mesenchymal cells that incompletely surround the en dothelium of the capillary. Hemangiopericytomas are
BROWN et al
•
SUPRACILIARY HEMANGIOPERICYTOMA
Fig 5. Variably sized, irregularly shaped vascular spaces are surrounded by plump spindle cells with indistinct cellular borders (hematoxylin and eosin; original magnification, X40).
Fig 7. Deposits of irregular, thickened basal lamina (asterisks) are present between tumor cells, which have a thin , discontinuous basal lamina (ar rows) (bar = 5 !Lm).
Fig 6. Tumor cell nuclei have a smooth chromatin pattern with small but distinct nucleoli. Notice the mitotic figure centrally (arrow) (hema toxylin and eosin; original magnification, X I00).
Fig 8. A vascular space containing an erythrocyte (E) and lined by an endothelial cell is separated from the tumor cell by reduplicated basal lamina (arrows) (bar = 5 !Lm).
uncommo n, and they most often occur in the retroperi toneum and lower extremities of adults as slowly growing 2 circumscribed masses. Due to their rich vascularity, tu mors may cause telangiectasias and/or varicosities of the overlying skin. The malignant potential of hemangiopericytomas is variable and unpredictable. Metastatic disease occurs in anywhere from 12 to 56% of patients and usually develops within 5 years of initial diagnosis, although late metastases are not rare. 2 Lungs and bone are the most common met astatic sites of involvement. Proposed histologic criteria portending a more aggressive course include the presence of 4 or more mitotic figures per 10 high-power fields, in creased cellularity, nuclear pleomorphism, and foci of 2 hemorrhage and necrosis. However, histologically "be nign" hemangiopericytoma has resulted in death due to metastatic spread. 5 Hemangiopericytoma-like patterns may be seen focally in other tumors, such as fibrous histiocytoma, synovial sarcoma, and mesenchymal chondrosarcoma, but in most
entities distin cases other characteristic features of these 2 guish them from hemangiopericytoma. Intraocular tu mors that may demonstrate a prominent vascular pattern include leiomyoma and schwannoma; imuunohisto chemical studies for the presence of smooth muscle and neural antigens, respectively, can aid in differentiating these neoplasms. 6 Electron microscopy may be necessary to confirm the diagnosis. Hemangiopericytoma tumor cells are charac terized by organelle-poor cytoplasm with elongate cyto plasmic processes, plasmalemma! pinocytotic vesicles, external basal lamina, usually incompletely encircling cells and forming extracellular clumps, and reduplicated basal lamina separating tumor cells from capillary endothelium. Orbital hemangiopericytomas have occurred with on enough frequency to elicit several series and reviews 10 57 9 optic a, conjunctiv the of the subject. • - Involvement 12 nerve, 11 and lacrimal sac also has been reported. Intra ocular hemangiopericytoma, however, has only been re ported twice. 3·4 In each case, the tumor was a well-cir 381
OPHTHALMOLOGY
•
MARCH 1991
cumscribed mass arising within uveal tissue of an adult female: one, a sessile, dome-shaped tumor of the mid peripheral choroid, 3 and the other a pedunculated tumor originating in the stroma of the pars plicata of the ciliary body. 4 In the current case, the hemangiopericytoma ex panded within the supraciliary and suprachoroidal spaces, displacing both the ciliary body and choroid toward the vitreous cavity. Telangiectasia of the overlying retinal vessels3 and prominent episcleral vessels4 were noted in association with the tumors in previous reports, and marked dilatation of episcleral vessels was a significant clinical and histopathologic finding in our case. Promi nence ofepiscleral vessels external to an intraocular tumor has been judged to be "a particularly important sign of ciliary body melanoma;" 13 hemangiopericytoma must now also be considered when prominent vessels are pres ent overlying an intraocular mass. Masses involving the ciliary body/choroid in children are distinctly uncommon. Reported diagnoses include leiomyoma, 13 melanoma, 14 hemangioma, 15 ·16 juvenile xanthogranuloma, 17 mesectodermal leiomyoma, 18 ade noma of the nonpigmented ciliary epithelium, 19 neuro fibroma, 20 neurilemoma, 21 and medulloepithelioma. 22
Since proper management for these conditions varies from corticosteroid therapy in cases of juvenile xanthogranu loma to enucleation or radiation therapy for melanoma, accurate clinical diagnosis is imperative. Magnetic resonance imaging has been judged superior to computed tomography in the detection and differential diagnosis of intraocular tumors. 23 ·24 Because of the small numbers oftumors evaluated other than melanoma, cor relation of signal characteristics with specific tumor types is not yet possible. However, due to the paramagnetic properties of melanin, melanotic melanomas have distinct signal characteristics on magnetic resonance imag ing. 23 - 25 Melanin contains stable free radicals that are paramagnetic, causing intraocular melanotic melanomas generally to appear hyperintense to vitreous on T 1 weighted MR images and hypointense to vitreous on T 2 weighted images. Amelanotic melanomas are only slightly hyperintense or isointense to vitreous on T 1-weighted im aging, and hypointense to vitreous on T 2-weighted im aging.24 Magnetic resonance imaging was helpful in distin guishing our patient's tumor from ciliary body melanoma. Although the MR signal characteristics of the tumor when compared with vitreous were not inconsistent with a di agnosis of melanoma, when compared with brain they were different from the usual pattern of signals described for intracerebral melanoma, where the tumor generally is hyperintense to white matter on T 1-weighted imaging and hypointense to white matter on Trweighted imaging. 25 In our case, the intraocular tumor was slightly hyperin tense to white matter on T 1-weighted images but signifi cantly hyperintense on T rweighted imaging. Comparison of tumor signals not only to vitreous but also to brain may prove beneficial in the clinical differential diagnosis of intraocular tumors. The pattern of MR images in our patient's tumor may provide an important clue to the clinical recognition of future cases of intraocular heman giopericytoma. 382
•
VOLUME 98
•
NUMBER 3
REFERENCES 1. Stout AP, Murray MR. Hemangiopericytoma: a vascular tumor featuring Zimmermann's pericytes. Ann Surg 1942; 116:26-33. 2. Enzinger FM, Weiss SW. Soft Tissue Tumors, 2nd ed. St. Louis: CV Mosby, 1988; 596-613. 3. Papale JJ, Frederick AR, Albert OM. Intraocular hemangiopericytoma. Arch Ophthalmol 1983; 101:1409-11. 4. Gieser SC, Hufnagel TJ, Jaros PA, et al. Hemangiopericytoma of the ciliary body. Arch Ophthalmol1988; 106:1269-72. 5. Henderson JW, Farrow GM. Primary orbital hemangiopericytoma: an aggressive and potentially malignant neoplasm. Arch Ophthalmol1978; 96:666-73. 6. Enzinger FM, Weiss SW. Soft Tissue Tumors, 2nd ed. St. Louis: CV Mosby, 1988; 83-101. 7. Brown ON, MacCarty CS, Soule EH. Orbital hemangiopericytoma: review of the literature and report of four cases. J Neurosurg 1965; 22:354-61. 8. Jakobiec FA, Howard GM, Jones IS, Wolff M. Hemangiopericytoma of the orbit. Am J Ophthalmol1974; 78:816-34. 9. Croxatto JO, Font RL. Hemangiopericytoma of the orbit: a clinico pathologic study of 30 cases. Hum Pathol1982; 13:210-8. 10. Grossniklaus HE, Green WR, Wolff SM, Iliff NT. Hemangiopericytoma of the conjunctiva: two cases. Ophthalmology 1986; 93:265-7. 11. Boniuk M, Messmer EP, Font RL. Hemangiopericytoma of the menin ges of the optic nerve. A clinicopathologic report including electron microscopic observations. Ophthalmology 1985; 92:1780-7. 12. Carnevali L, Trimarchi F, Rosso R, Stringa M. Haemangiopericytorna of the lacrimal sac: a case report. Br J Ophthalrnol1988; 72:782-5. 13. Green WR. The uveal tract. In: Spencer WH, ed. Ophthalmic Pathology: An Atlas and Textbook, 3rd ed., Vol. 3. Philadelphia: WB Saunders, 1986; 1352-2072. 14. Leonard BC, Shields JA, McDonald PR. Malignant melanomas of the uveal tract in children and young adults. Can J Ophthalmol 1975; 10: 441-9. 15. Jones IS, Cleasby GW. Hemangioma of the choroid: a clinicopathologic analysis. Am J Ophthalmol1959; 48:612-28. 16. Witschel H, Font RL. Hemangioma of the choroid: a clinicopathologic study of 71 cases and a review of the literature. Surv Ophthalmol 1976; 20:415-31. 17. Zimmerman LE. Ocular lesions of juvenile xanthogranuloma: nevo xanthoendothelioma. Trans Am Acad Ophthalmol Otolaryngol1965; 69:412-42. 18. Shields JA, Shields CL, Eagle RC Jr. Mesectodermal leiomyoma of the ciliary body managed by partial lamellar iridocyclochoroidectomy. Ophthalmology 1989; 96:1369-76. 19. Patrinely JR, Font RL, Campbell RJ, Robertson OM. Hamartomatous adenoma of the nonpigmented ciliary epithelium arising in iris-ciliary body coloboma. Light and electron microscopic observations. Oph thalmology 1983; 90:1540-7. 20. Nicholson DH, Green WR. Pediatric Ocular Tumors. New York: Masson USA, 1981; 87-95. 21. Vannas S, Raitta C, Tarkkanen A. Neurilemmoma of the choroid in Recklinghausen's disease. Acta Ophthalmol Suppl 1974; 123:126 33. 22. Broughton WL, Zimmerman LE. A clinicopathologic study of 56 cases of intraocular medulloepitheliomas. Am J Ophthalmol 1978; 85:407 18. 23. Mafee MF, Peyman GA, Peace JH, et al. Magnetic resonance imaging in the evaluation and differentiation of uveal melanoma. Ophthalmology 1987; 94:341-8. 24. Peyster RG, Augsburger JJ, Shields JA, et al. Intraocular tumors: evaluation with MR imaging. Radiology 1988; 168:773-9. 25. Woodruff WW Jr, Djang WT, Mclendon RE, et al. Intracerebral ma lignant melanoma: high-field-strength MR imaging. Radiology 1987; 165:209-13.