Ocular neovascularization in a patient with Fanconi anemia

CASE REPORT: An 11-year-old girl diagnosed with Fanconi anemia was referred to us for redness and pain in her right eye. Findings in the right eye included visual acuity of counting fingers, neovascular glaucoma, vitreous hemorrhage, optic disc neovascularization, and features of peripheral ischemic retinopathy. Findings in the left eye included peripheral retinal neovascularization and areas of retinal capillary nonperfusion. COMMENTS: Patients with Fanconi anemia may develop ocular neovascularization with subsequent severe visual loss due to vitreous hemorrhage or neovascular glaucoma. Regular ophthalmic examination, including ophthalmoscopy and fluorescein angiography in selected cases, is recommended in such patients.     

内皮抑素基因转移抑制视网膜新生血管的实验研究

目的评价脂质体介导的内皮抑素(ES)基因转移抑制缺氧诱导的小鼠视网膜新生血管的效果。探讨基因转移抑制视网膜新生血管的可行性。方法制备阳离子脂质体及PCDNA3ES复合物。选1周龄C57Bl/6N小鼠置于氧浓度为(75±2)%的氧箱中5d。回到正常环境中诱导视网膜新生血管模型。在小鼠离开氧箱的当日,向ES注射组鼠玻璃体腔注射2μl脂质体PCDNA3ES复合物;载体对照组注射等量脂质体空白载体复合物;空白对照组小鼠注射等量PBS。采用ES抗体免疫组化方法检测ES蛋白在视网膜的表达;回到正常环境中后5d,采用荧光标记的右旋糖酐血管灌注下视网膜铺片方法观察视网膜新生血管的分布;组织学切片观察比较突破视网膜内界膜的血管内皮细胞数量;透射电镜观察ES转移对视网膜超微结构的影响。结果免疫组化检查发现ES注射组小鼠玻璃体腔注射ES后24h开始有ES表达,主要位于视网膜神经纤维层细胞中,维持至少2周仍见表达;视网膜铺片观察可见空白对照组在无灌注区边缘均可见新生血管芽及荧光渗漏。ES注射组见新生血管芽明显减少;组织学检查ES注射组较其他两组突破视网膜内界膜的细胞数量减少,差异有统计学意义;ES转移后电镜下视网膜各层超微结构未见明显改变。结论采用玻璃体腔注射方法行脂质体介导的内皮抑素基因转移可以一定程度抑制缺氧诱导的小鼠视网膜新生血管生长,对视网膜无明显的毒副作用。应进一步优化转移条件以提高治疗效果。     

Retinitis pigmentosa and retinal neovascularization

Four patients with retinitis pigmentosa and either disc or peripheral retinal neovascularization with recurrent vitreous hemorrhage are described. One patient with peripheral retinal neovascularization also had rubeosis and neovascular glaucoma. The effects of relative hyperoxia on the retinal microcirculation in retinitis pigmentosa as well as intraocular inflammation may account for such changes. Laser photocoagulation appears effective in preventing vitreous hemorrhage in these patients, but systemic administration of corticosteroids did not cause the new vessels to regress.     

Management of proliferative diabetic retinopathy

Proliferative diabetic retinopathy is characterized by neovascularization originating from the retina and/or optic disk in patients with diabetes mellitus. The role of vascular endothelial growth factor appears to be central in the pathogenesis of proliferative diabetic retinopathy. Advanced glycation end products are important in the development of vitreous abnormalities in proliferative diabetic retinopathy. The majority of the neovascular membranes are adherent to the posterior vitreous cortex. When the posterior hyaloid exerts traction, the edges of the neovascular complex are pulled forward, resulting in vitreous hemorrhage. Tractional and/or rhegmatogenous retinal detachments can occur. The Diabetic Retinopathy Study demonstrated the ability of panretinal photocoagulation to reduce the rate of severe visual loss by 50% for eyes with high-risk characteristics, defined as neovascularization originating from the optic disk > 1/3 disk diameter, any neovascularization originating from the optic disk with hemorrhage, and neovascularization originating from the retina with vitreous hemorrhage. The Early Treatment Diabetic Retinopathy Study showed that patients with type II diabetes mellitus who were older than 40 with severe nonproliferative diabetic retinopathy (defined as hemorrhages in four quadrants, venous beading in two quadrants, or intraretinal microvascular abnormalities in one quadrant) also benefited from early panretinal photocoagulation. The Diabetic Retinopathy Vitrectomy Study showed that early vitrectomy (within 6 months of onset of vitreous hemorrhage) was associated with better results in type I diabetes mellitus patients only. The goals of vitreous surgery are to remove the vitreous, including the posterior hyaloid, and to relieve traction from fibrovascular tissue. Delamination and segmentation techniques have been used in the excision of fibrovascular growth on the internal limiting membrane and extending into the vitreous. Panretinal photocoagulation is an integral component of vitrectomy for proliferative diabetic retinopathy. Anti-vascular endothelial growth factor agents may be used in addition to laser as an adjunct to reduce the risk of neovascularization. Vitrectomy surgery may have intraoperative and postoperative complications, including cataract, anterior hyaloidal fibrovascular proliferation, fibrovascular ingrowth, retinal detachment, and recurrent vitreous hemorrhage. Visual potential depends on the preoperative and postoperative status of the macula, as well as on retinal perfusion and the health of the optic nerve. With the improvement in instruments, techniques, and drugs, the results of vitrectomy in proliferative diabetic retinopathy are improving.     

Spontaneous regression (autoinfarction) of proliferative sickle retinopathy.

Of 45 patients with proliferative sickle retinopathy in stages III, IV, and V, nine patients (eight with hemoglobin SC disease, one with sickle cell thalassemia) showed spontaneous regression (autoinfarction) of retinal sea fans. One mechanism involved in autoinfarction of neovascular tissue is progressive, centripetal retraction of the anterior vascular arcade of the peripheral retina. In addition, vitreous traction on feeder vessels may result in sluggish blood flow and occlusion of these vessels, or may tear the sea fan completely away from its feeder vessels. In view of the many incidences of vitreous hemorrhages that occur in patients with proliferative retinopathy, however, we recommend treatment of neovascularization rather than prolonged observation.     

血管内皮生长因子受体KDR基因胞外段1-3区基因转染抑制氧诱导小鼠视网膜新生血管的研究

目的 评价脂质体介导的血管内皮生长因子受体KDR基因胞外段1-3区(KDRn3)基因转染抑制氧诱导的视网膜新生血管的效果.方法 选1周龄C57Bl/6N小鼠置于氧浓度为75%±2%的氧箱中5 d.回到正常环境中诱导视网膜新生血管模型.在小鼠离开氧箱的当日,向转染组小鼠玻璃体腔注射脂质体pEGFP-N1/KDRn3复合物1 μl;脂质体对照组注射等量脂质体;空白对照组小鼠注射等量PBS.回到正常环境中后5 d,采用视网膜铺片及视网膜冰冻切片在激光共聚焦显微镜下观察绿色荧光蛋白在视网膜的表达;采用荧光标记的右旋糖酐血管灌注下视网膜铺片方法观察视网膜新生血管的分布并测量无灌注区面积;组织学切片观察比较突破视网膜内界膜的血管内皮细胞数量.多组比较采用方差分析,有统计意义后进行两两比较的q检验.结果 转染组视网膜铺片见视网膜局部散在点状绿色荧光信号,空白对照组与脂质体对照组未见绿色荧光信号;视网膜冰冻切片见转染组视网膜神经节细胞层、内核层部分细胞胞质内见绿色荧光表达,空白对照组与脂质体对照组视网膜各层未见绿色荧光表达;视网膜铺片观察可见空白对照组与脂质体对照组在无灌注区边缘均可见新生血管芽及荧光渗漏,转染组见新生血管芽明显减少,生后第17天A、B、C 3组新生血管模型小鼠各组视网膜无灌注区面积分别为(1.33±0.49)、(2.75±0.70)、(2.12±0.35)mm2,组间比较差异有统计学意义(F=17.61,P＜0.01＝.正常对照组及A、B、C组视网膜表面突破内界膜的血管内皮细胞核计数分别为0.20±0.51、13.58±2.48、23.05±3.40及21.70±2.89,组间比较差异有统计学意义(F=1085.25,P＜0.05＝.结论 pEGFP-N1/KDRn3基因转染可不同程度抑制氧诱导C57,Bl/6J小鼠视网膜新生血管的生长.

Abstract：

Objective To evaluate the effect of liposome mediated plasmids KDRn3 injected into the vitreous to inhibit experimental retinal neovascularization. Methods One-week-old C57BL/6N mice were exposed to 75% ± 2% oxygen for 5 days, then returned to the room air to induce retinal neovascularization. Cationic liposome mediated KDRn3 comp-lex (1 μl) was injected into the vitreous in the treatment group. PBS 1 μl or liposome were injected in the control group. The pEGFP-N1/ KDRn3 expression was observed by using fluorescence microscope. Retinal neovascularization was evaluated by counting the number of vascular endothelial cell nuclei on the vitreal side of the inner limiting membrane of the retina and measuring the areas of non-perfusionsin in central retina. Results KDRn3 protein was expressed both in the ganglion layer and in the inner layer. Retinal wholemount preparation of retinal neovascular animal model showed that prominent neovascular tuft and fluorescein leakage and large areas of non-perfusionsin in central retina. Fewer neovascular tufts and fewer areas of non-perfusionsin could be seen after pEGFP-N1/KDRn3 injection. There were statistic differences between control group and pEGFP-N1/ KDRn3 injecting group with the number of vascular endothelial cell nuclei on the vitreal side of the inner limiting membrane of the retina(0. 20 ±0. 51, 13. 58 ±2. 48,23. 05 ±3. 40,21. 70 ± 2. 89;F = 1085. 25, P ＜ 0. 05 ) and the areas of non-perfusionsin in central retina [(1. 33 ± 0. 49 ) , ( 2. 75 ± 0. 70 ) , ( 2. 12 ± 0. 35) mm2; F = 17. 61 , P ＜ 0. 01] . Conclusion pEGFP-N1/KDRn3 gene transfer can inhibit retinal neovascularisation in C57Bl/6J mice of ischaemia-induced retinal neovascularisation on some extent.     

Clinical picture of isolated retinal vasculitis

Clinical picture of isolated retinal vasculitis (IRV) in 43 patients (25 men and 18 women) aged 22-42 years is analyzed. IRV was bilateral in 88.4% cases and involved the veins. Two forms of disease were distinguished: peripheral (in 75%) and central-peripheral (25%). Both forms were characterized by a high hemorrhagic activity, occlusion of vessels, ischemic zones and neovascularization of the retina and optic disk, but these signs were more frequent in central peripheral form of IRV. IRV is a grave disease leading to poor vision or blindness in 18% cases. The onset is poorly manifest with floating spots and blurred vision; the main symptom is vitreous hemorrhage. Visual acuity was significantly decreased in patients with occlusive IRV in comparison with those without occlusions (0.32 +/- 0.37 vs. 0.77 +/- 0.28). The earliest changes can be detected mainly in the peripheral parts of the retina. This necessitates special attention of ophthalmologist to seemingly negligible complaints of patients and thorough examination of the fundus oculi, particularly of its peripheral sections, which can be performed only on condition of adequate mydriasis. Only timely diagnosis and early pathogenetic therapy can decrease the probability of such complications as hemophthalmos, retinal neovascularization, detachment of retina, and neovascular glaucoma, and prevent disability.     

Macular Hole following Intravitreal Bevacizumab Injection in Choroidal Neovascularization Caused by Age-Related Macular Degeneration

This report describes formation of a full-thickness macular hole subsequent to an injection of bevacizumab for the treatment of neovascular AMD. This complication may be caused by focal tractional forces on the retinal surface due to either vitreous incarceration at the injection site or contraction of the choroidal neovascularization membrane. Alternatively, it may be due to a toxic effect of bevacizumab on a previously compromised retina.     

Vitreous oxygen tension of proliferative diabetic retinopathy]

The authors investigated the vitreous oxygen tension in 30 eyes of 29 cases of proliferative diabetic retinopathy patients in order to determine the distribution of oxygen tension and the possible role of neovascular tissue in tissue oxygenation. Vitreous oxygen tension was measured using a polarographic oxygen electrode and a PO2 monitoring system (PO-2080). Prior to pars plana vitrectomy, the oxygen electrode was inserted into the vitreous cavity under microscopic observation with dim illumination transmitted fiberoptically. The respective oxygen tension at the mid-vitreous cavity, above the optic disc, above the macula, above the neovascular tissue, in the peripheral vitreous, above the photocoagulated retina and above the non-photocoagulated retina were 15.8 +/- 4.7 mmHg, 31.2 +/- 10.0 mmHg, 17.1 +/- 4.0 mmHg, 32.0 +/- 9.9 mmHg, 15.6 +/- 5.1 mmHg, 16.5 +/- 5.5 mmHg and 18.6 +/- 4.9 mmHg. The oxygen tension values above the neovascular tissue and above the optic disc showed statistically significantly higher values than that of midvitreous cavity. We assume this to be due to differences between the oxygen demand and supply on the neovascular tissue, because in these tissues there are large amounts of vessels and blood flow compared to oxygen consumption. Therefore residual oxygen causes oxygen flow from the neovascularization to the mid-vitreous. This outcome is one of the facts which supports the hypothesis that neovascular tissues develop in order to compensate for retinal ischemia by releasing oxygen.     

Histopathological findings of X-linked retinoschisis with neovascular glaucoma

· Background: X-linked retinoschisis (XLRS) is rarely complicated by neovascular glaucoma. Only a few reports of XLRS histopathological findings with neovascular glaucoma have been published. · Methods: A 41-year-old man with XLRS complicated by neovascular glaucoma in his left eye was examined with electroretinography, B-scan, ultrasound biomicroscopy and computed tomography. He was examined by ophthalmoscopy and fluorescein angiography in the other eye. An enucleation was performed in his left eye due to uncontrollable high intraocular pressure and persistent ocular pain. We examined the enucleated eye histopathologically. · Results: Examination of the enucleated eye showed nuclear sclerosis of the lens, pigmented retrolental membrane and retinoschisis which separated the inner layer of the retina and made a large space in the vitreous cavity without any apparent detachment of the outer layers of the retina. Sclerotic vessels were present histopathologically in both the inner and outer layers of the retina. There was a peripheral anterior synechia, ectropion uveae and a fibrovascular membrane, which contained many lumina of neovascularization, indicating marked rubeosis iridis. Small cystic spaces were observed in both the schitic retina in the peripheral region and the foveal schisis at the outer layer of the retina. The photoreceptor cells had become markedly atrophied and multiple regions of calcification were observed. The optic nerve showed severe atrophy with gliosis, but the central retinal artery and vein were still open within the nerve. · Conclusions: These histopathological findings suggest that rubeosis iridis may have developed secondarily to retinal ischemia due to occlusion of the retinal blood vessels. Received: 2 March 1999 Revised version received: 12 May 1999 Accepted: 26 May 1999     

骨髓间充质干细胞治疗视网膜新生血管性疾病的研究进展

视网膜新生血管性疾病并非独立的一种眼病,常见于许多眼病中,如早产儿视网膜病变、糖尿病视网膜病变、年龄相关性黄斑变性、视网膜中央静脉阻塞和视网膜静脉周围炎等都会形成新生血管,是严重损害视力的病变。此类疾病丧失正常血管的结构和功能,引起病理性出血、渗出、水肿和视网膜脱离等病理性改变,是视力丧失的主要原因,已经成为世界范围的致盲性疾病。目前主要的治疗方法为针对病因进行激光封闭,或行玻璃体切除术,或是反复、多次玻璃体腔注射抗血管内皮生长因子,虽然短期效果好,但不能防止复发,目前仍没有长期有效的治疗方法。干细胞治疗的出现为此提供了潜在的替代疗法。本文将对骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)在视网膜新生血管疾病中的最新应用进展作一综述,展示其移植优势和良好的临床应用前景。     

Presumed retinovitreal neovascularization in dystrophic retinas of spontaneously hypertensive rats

The authors have observed abnormal blood vessels, strongly suggestive of neovascular proliferation, arising from the retinal circulation and extending through the inner limiting membrane of the retina into the vitreous in five spontaneously hypertensive (SHR) rats with severe retinal dystrophy. The animals in whom these presumptive retinovitreal new vessels occurred were all 15 mo of age or older. The new vessels frequently demonstrated thinned and, rarely, fenestrated endothelium, abnormal intracellular junctions, increased numbers of endocytic vesicles, bizarre appearing pericytes, and highly abnormal basement membranes, features that have been observed in retinovitreal new vessels in proliferative retinopathies in humans. Unlike such new vessels arising from the human retinal circulation, however, those that we observed in dystrophic rat retinas were usually surrounded by proliferating retinal pigment epithelial cells within the retinal substance. Unlike the vessels, the pigment epithelial cells did not break through the inner limiting membrane of the retina to enter the vitreous. The pigment epithelial cells that made contact with the internal limiting membrane of the retina demonstrated apical and basal plasma membrane specializations that are typical of these cells in their normal anatomical location, while pigment epithelial cells migrating in cords through the neural retina lacked such specializations. This animal model may be of great value in understanding the mechanisms of retinal neovascularization.     

Talc emboli and retinal neovascularization in a drug abuser.

A 38-year-old male drug abuser had multiple emboli in the retinal circulation of the posterior pole of both eyes. He showed widespread peripheral retinal capillary nonperfusion and neovascular proliferation at the junction of perfused and nonperfused retina. The emboli were considered to be talc particles from the intravenous administration of suspensions of oral medications. The presumed mechanism of development of neovascularization in this case was the filtering out of the particles by the retinal vasculature with vaso-occlusion, ischemia and subsequent retinal neovascularization.     

氧诱导的血管增生性视网膜病变小鼠模型

目的 建立可量化的血管增生性视网膜病变小鼠模型。方法 将鼠龄为7d的C57BL/6J幼鼠17只暴露于75％氧浓度环境下饲养持续5d,然后回到正常空气中饲养;17只同龄幼鼠置于正常空气环境中饲养作为对照。ADP酶法视网膜铺片了解视网膜血管的改变;用组织切片观察并计数突破视网膜内界膜的内皮细胞核数目;视网膜组织切片用CD31进行免疫组织化学染色。结果 持续高浓度氧使幼鼠视网膜血管收缩、分支闭塞、中央部可见灌注降低,相对低氧使视网膜血管扩张、增生。组织切片可见正常对照组平均每张切片突破内界膜内皮细胞核数目<1个,给氧组平均24个/切片,两组比较差别有显著性意义(P<0.01)。给氧组视网膜组织切片经用CD31抗体处理后显示内界膜玻璃体面细胞染色阳性。结论 该模型具有可重复性强、可定量研究的优点,是进行视网膜新生血管发生机制及药物干预的合适模型。     

Peripheral choriovitreal neovascularization in proliferative diabetic retinopathy: histopathologic and ultrastructural study

We describe the histopathologic and ultrastructural evidence of choriovitreal neovascularization in the peripheral fundus of a non-vitrectomized eye with proliferative diabetic retinopathy (PDR). One eye with PDR was surgically enucleated because of neovascular glaucoma and studied with light and electron microscopy. The eye had neovascular membranes at the ora serrata of the peripheral fundus. The newly formed vessels originated from the choroid, passed through Bruch's membrane and the retina, and extended into the vitreous. These vessels had either developing or mature characteristics. The endothelial cells of the developing vessels contained a bulky cytoplasm with many intracytoplasmic filaments, ribosomes and rough endoplasmic reticulum. Budding endothelial cells were frequently found in the developing vessels. The endothelial cells of the mature vessels had attenuated cytoplasm and fenestrations with diaphragms. These observations suggest that choriovitreal neovascularization in the peripheral fundus is one of the features of PDR.     

Eales’ disease and juvenile glaucoma a case report

Eales’ disease is an idiopathic vasculopathy affecting the retina of young adults. The disease is characterized by sheathing of the retinal vessels and areas of nonperfusion in the peripheral retina. Recurrent vitreous and retinal hemorrhages can lead to various complications, including hemorrhagic glaucoma owing to neovascularization of the iris-corneal angle, retinal detachment, and visual loss. In this report we describe a case of assocation of Eales’ disease and open angle glaucoma discussing pathophysiological mechanins correlating ocular hydrodynamics and hemodynamics under normal and disease states. The authors state that they do not have any significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article. They also do not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.     

Vitreous hemorrhage and neovascular proliferation in multiple sclerosis

We report the case of a 40 year-old man with multiple sclerosis, who presented a bilateral proliferative retinopathy responsible for a vitreous hemorrhage. Examination of the periphery of the retina showed diffuse retinal periphlebitis; fluorescein angiograms showed a peripheral retinal ischemic syndrome with secondary neovascularization. Several recent studies have show that retinal periphlebitis is a frequent finding in multiple sclerosis; but to our knowledge a retinal ischemic syndrome with neovascularization has seldom been reported.     

增生型糖尿病视网膜病变玻璃体切除手术后再出血病因及治疗

目的 分析增生型糖尿病视网膜病变(PDR)玻璃体切割手术后再出血病因，观察再治疗效果。 方法 回顾分析302例PDR患者315只患眼接受玻璃体切割手术治疗后32只眼再出血并再次治疗后随访3~48个月（平均随访时间12个月）的临床资料。 结果 PDR玻璃体切割手术后再出血发生率为10%，再出血发生时间为手术后1～210 d，平均时间为51 d。再出血的主要原因中，28%为巩膜切口纤维血管向内生长，19%为视盘表面残存新生血管膜或血管残端处理不当，22%为视网膜激光光凝不足，9%为视网膜表面新生血管膜剥除不彻底，6%为视网膜静脉阻塞，16%为外力作用。通过冷凝巩膜切口处纤维血管、剥离视盘和视网膜表面残存新生血管膜并电凝视盘表面血管残端、补充视网膜激光光凝、 包扎双眼等治疗，再出血眼视力提高者占91%，视力下降者占9%。再次手术后并发症主要包括再次出血、虹膜后粘连、晶状体混浊加重、角膜上皮愈合延迟等。 结论 PDR玻璃体切割手术治疗后再出血的主要原因是巩膜切口纤维血管向内生长、视盘表面和（或）视网膜表面新生血管膜剥除不彻底、血管残端处理不当、视网膜激光光凝不足和外力作用。处理好巩膜切口、彻底剥离视盘和视网膜表面新生血管膜、电凝血管残端以及足够的视网膜激光光凝是预防和治疗PDR玻璃体切割手术后再出血的有效方法。(中华眼底病杂志,2007,23:238-240)      

Vitreous: an inhibitor of retinal extract-induced neovascularization

One of the major problems in assessing neovascularization in mammalian experimental animal models is the immunologic response of the host to stimuli from nonautologous species. Hence, crude bovine vitreous and retinal extracts may produce a complex immune reaction when tested in the rabbit. To circumvent this problem, the chicken chorioallantoic membrane (CAM) assay is most appropriate. In this study the CAM assay for angiogenesis has been modified to study antiangiogenic substances. The modified assay is described in detail and used to demonstrate for the first time the inhibition by adult bovine vitreous of neovascularization induced by extracts of adult bovine retina. In addition to vitreous, three common glycosaminoglycans (keratan sulfate, chondroitin sulfate C, and hyaluronic acid) were assayed for antiangiogenic activity. The results indicate that vitreous inhibition of retinal extract-induced neovascularization is dose dependent, while the sulfated glycosaminoglycans tested had no antiangiogenic activity. A commercial preparation of bovine vitreous hyaluronic acid exhibited a slight, but not statistically significant, inhibitory activity. When vitreous extracts were digested with hyaluronidase, no loss of antiangiogenic activity occurred. These results suggest that the inhibitor of angiogenesis from adult vitreous is probably not a common glycosaminoglycan. The results are consistent with the hypothesis that antiangiogenic substance(s) in vitreous and angiogenic components from retina may act as natural antagonists in controlling the process of retinal neovascularization.     

Presumed combined hamartoma of the retina and retinal pigment epithelium with preretinal neovascularization

PURPOSE: To describe a case of presumed combined hamartoma of the retina and retinal pigment epithelium associated with preretinal neovascularization. DESIGN: Observational case report. METHODS: We report clinical and angiographic findings of a 26-year-old woman. RESULTS: The patient presented with mild vitreous hemorrhage and slowly decreasing vision in the right eye. A combined hamartoma of the midperipheral retina and retinal pigment epithelium with an epiretinal membrane causing traction to the macula was found. Fluorescein angiography showed areas of capillary nonperfusion and a large preretinal neovascularization peripheral to the hamartoma. CONCLUSIONS: A combined hamartoma may be associated with retinal capillary nonperfusion and preretinal neovascularization, suggesting that significant retinal ischemia can occur with a combined hamartoma.