Combined Retinal Hamartomas Leading to the Diagnosis of Neurofibromatosis Type 2

Changing trends in pseudoretinoblastoma diagnoses: A 10 year review from the United Kingdom

AIM

To study the different types and frequency of pseudoretinoblastoma (pseudoRB) lesions who present to a retinoblastoma centre due to concern that the condition may be retinoblastoma.

METHODS

A retrospective chart review of 341 patients presenting sporadically to the Royal London Hospital from January 2009 to December 2018.

RESULTS

220 patients (65%) were confirmed to have retinoblastoma, while 121 (35%) had pseudoRB. There were 23 differential diagnoses in total. The top 3 differential diagnoses were Coats' disease (34%), Persistent Foetal Vasculature (PFV) (17%) and Combined Hamartoma of Retina and Retinal Pigment Epithelium (CHR-RPE) (13%). PseudoRBs differed with age at presentation. Under the age of 1 (n = 42), the most likely pseudoRB conditions were PFV (36%), Coats' disease (17%) and CHR-RPE (12%). These conditions were also the most common simulating conditions between the ages of 1 and 2 (n = 21), but Coats' disease was the most common in this age group (52%), followed by CHR-RPE (19%) and PFV (14%). Between the ages of 2 and 5 (n = 32), Coats' disease remained the most common (44%) pseudoRB lesion followed by CHR-RPE (13%), or PFV, Retinal Astrocytic Hamartoma (RAH), familial exudative vitreoretinopathy (FEVR) (all 6.3%). Over the age of 5 (n = 26), pseudoRBs were most likely to be Coats' disease (35%), RAH (12%), Uveitis, CHR-RPE, FEVR (all 7.7%).

CONCLUSION

35% of suspected retinoblastoma cases are pseudoRB conditions. Overall, Coats' disease is the most common pseudoRB condition, followed by PFV. Hamartomas (CHR-RPE & RAH) are more prevalent in this cohort, reflecting improvements in diagnostic accuracy from referring ophthalmologists.

Structural Abnormalities of the Central Retina in Neurofibromatosis Type 2

INTRODUCTION

This case-control study seeks to systematically characterize the central retinal findings in a large cohort of patients with neurofibromatosis type 2 (NF2) using spectral domain optical coherence tomography (SD-OCT) as well as the examination of the potential use of this technique as a diagnostic tool in NF2.

METHODS

Fifty-four patients with an NF2 diagnosis seen in a quaternary national service were age- and gender-matched to 55 controls from the normal population. Two masked assessors categorized SD-OCT images using predefined abnormalities: retinal tufts, epiretinal membrane (ERM) appearance, retinal hamartoma, and foveal contour. Specificity, sensitivity, and positive and negative predictive values were calculated for each retinal abnormality. Trends of retinal abnormalities with NF2 genetic severity groups (1. tissue mosaic; 2A. mild classic; 2B. moderate classic; and 3. severe) were investigated.

RESULTS

We found retinal abnormalities in 26 patients with NF2 (48%) and 2 control patients (4%); retinal tufts were the most common abnormality therein (43%) and were not seen in controls. The specificity and sensitivity of the graded abnormalities on OCT scans in NF2 were 96% and 48%, respectively, with a positive predictive value of 93%. In our cohort, retinal tufts had a specificity of 100%, a sensitivity of 43%, and a positive predictive value of 100%. Retinal hamartomas were seen only in NF2 patients (35% sensitivity and 100% specificity). ERMs had 96% specificity and 13% sensitivity. The proportion of patients with retinal abnormalities increased statistically significantly with NF2 genetic severity; all patients within the 3. severe genetic severity had an abnormal SD-OCT.

DISCUSSION/CONCLUSION

We present a systematic study of central retinal abnormalities in an NF2 population as seen on SD-OCT imaging. Our results show a high frequency of retinal abnormalities that are readily detected by SD-OCT imaging. The presence of retinal tufts may be a novel marker of NF2 with both high specificity and a positive predictive value for NF2, compared to other well-known ocular features of NF2, and may have a place in the NF2 diagnostic criteria.

[Tumors and Pseudotumors of the Retina and the Ciliary Epithelium]

The variety of retinal tumors ranges from harmless lesions to benign, locally destructive tumors and life-threatening diseases, and they are not always easy to distinguish from each other. The differential diagnosis includes real neoplasia, reactive inflammatory pathologies and vascular anomalies of the fundus as well. If possible, the diagnosis should be made clinically in order to avoid the danger of tumor cell spread via invasive diagnostic tools. Nevertheless, genetic analysis of the pathology is gaining more importance and adds to the precise characterization of the diagnosis. Depending on the tumor entity, therapy in a specialized center is necessary.

Tumoren und Pseudotumoren der Netzhaut und des Ziliarepithels

Die Varietät retinaler Tumoren reicht von harmlosen Läsionen über benigne, lokal destruierende Tumoren bis hin zu lebensbedrohlichen Erkrankungen. Nicht immer lassen sie sich einfach voneinander unterscheiden. Die Diagnose sollte nach Möglichkeit klinisch gestellt werden wegen der Gefahr einer Tumorzellverschleppung durch invasive Diagnostik. Jedoch rückt die genetische Charakterisierung der Läsion immer mehr in den Vordergrund. Je nach Entität ist eine Therapie in einem spezialisierten Zentrum notwendig.

A child with unilateral disk elevation

A healthy 7-year-old girl underwent a routine eye examination and was referred for unilateral, left optic nerve swelling. Best-corrected visual acuity in the affected eye was 20/20 with full Ishihara color plates and no relative afferent pupillary defect. Initial extensive workup was normal for any cause of unilateral disk swelling. When the patient returned a few years later with decreased vision, a thickened, gray-white preretinal tissue with surrounding retinal contraction and a surrounding charcoal gray lesion had developed in her optic nerve. Spectral-domain optical coherence tomography over the optic nerve demonstrated distortion of the inner retinal architecture, a dense epiretinal membrane, and high internal reflectivity. Clinical examination and imaging revealed a diagnosis of combined hamartoma of the retina and retinal pigment epithelium.

Multimodal imaging of combined hamartoma of the retina and retinal pigment epithelium associated with an acquired vitelliform lesion

Background

We present a case of a combined hamartoma of the retina and retinal pigment epithelium associated with a subfoveal acquired vitelliform lesion induced by vitreomacular traction. The purpose of this report is to present a unifying hypothesis of these concurrent findings, as aided by multimodal imaging.

Case Presentation

A 25-year-old white man presented with a 6-month history of a visual disturbance in his left eye. At presentation, ophthalmic assessment showed a combined hamartoma adjacent to his optic nerve that had caused marked corrugation within the inner retinal surface. An acquired vitelliform lesion was present in the macula with an associated epiretinal membrane as demonstrated on spectral-domain optical coherence tomography. Optical coherence tomography angiography corroborated the clinical diagnosis of combined hamartoma.

Conclusions

We are not aware of previous cases of a combined hamartoma associated with an acquired vitelliform lesion. As previously proposed in acquired vitelliform lesions related to epiretinal membrane and vitreoretinal traction, we believe that macular tractional forces might interfere with retinal pigment epithelium phagocytosis of shed outer segments, leading to the occurrence of this acquired vitelliform lesion.

Pigmented Lesions of the Retinal Pigment Epithelium

: The primary eye care practitioner assumes an important role in clinical decisions involving the differentiation between malignant and nonmalignant pigmented lesions. A misdiagnosis may have profound consequences on patient management and visual or life prognosis. However, information on these lesions, particularly their appearance using advanced imaging, is fragmented throughout the literature. The purpose of this review is to describe these features in detail, so that the implications of this information on clinical practice are more readily apparent. Clinically relevant descriptions of pigmented lesions of the retinal pigment epithelium using traditional and advanced imaging modalities in the literature were collated and integrated with findings from patients seen at the Centre for Eye Health. The information was then organized and tabulated. Finally, a flow diagram was created to be used as a clinical reference in the differential diagnosis of pigmented lesions of the retinal pigment epithelium.

[Early type 2 neurofibromatosis and congenital retinal hamartoma]

Neurofibromatosis type 2 (NF2) is a heritable syndrome characterized by multifocal proliferation of neural crest-derived cells. It has long been regarded as an adolescent- and adult-onset disease. We report here on a case of a 6-year-old girl with infantile-onset clinical signs. The girl, who had a history of amblyopia and congenital retinal hamartoma, presented with rough dimness of visual acuity. Cerebral magnetic resonance imaging found a left voluminous fronto-temporal tumor including the chiasma and optical nerves. Vestibular and cervical nerve schwannomas were also found. She underwent a first neurosurgical partial excision and histopathology revealed meningioma. Postoperative radiotherapy was necessary due to a secondary increase of the tumor size. Subsequent molecular testing revealed a NF2 gene abnormality. NF2 can become evident in infancy but clinical early symptomatology is often different: ocular symptoms and neurological problems are common. There is no consensus on the treatment of tumors involving the central and peripheral nervous system, abstention being usual. In case of severe signs, surgery and radiotherapy can be proposed. The diagnosis of a hamartoma must lead to multidisciplinary follow-up.

Bilateral Combined Hamartomas of the Retina and Retinal Pigment Epithelium as the Presenting Feature of Neurofibromatosis Type 2 (Wishart Type)

An 8-week-old healthy female infant manifested leukocoria and reduced vision in the left eye. She was found to have bilateral combined hamartomas of the retina and retinal pigment epithelium. There were no other features of neurofibromatosis type 2 and brain imaging was normal. At 6 months of age, subtle posterior subcapsular lens opacity was noted in the right eye. Genetic testing for neurofibromatosis type 2 was advised but not performed. At 3 years of age, leg weakness with quadriceps atrophy led to neuroimaging and detection of multiple tumors, including bilateral vestibular schwannomas and cervical, thoracic, and lumbar paraspinal schwannomas. Molecular testing revealed a nonsense mutation in the neurofibromatosis type 2 gene. Bilateral combined hamartomas were the presenting feature of a severe phenotype of neurofibromatosis type 2.

Reactive retinal astrocytic tumors (so-called vasoproliferative tumors): histopathologic, immunohistochemical, and genetic studies of four cases

PURPOSE

To evaluate the cellular nature of and diagnostic terminology used in connection with acquired retinal "vasoproliferative tumors."

DESIGN

Retrospective clinicopathologic study.

METHODS

Clinical records and microscopic slides of 4 enucleated globes were reviewed. Special stains and immunohistochemical probes for CD31, CD34, p53, glial fibrillary acidic protein (GFAP), CD163, and Ki67 (cell replication) were employed; ultrastructural and fluorescence in situ hybridization (FISH) analyses were performed.

RESULTS

Tumors were located inferotemporally in middle-aged patients. They were uniformly composed of compacted elongated, GFAP-positive spindle cells (due to intermediate filaments identified ultrastructurally) with a Ki67 index of less than 1%. Rosenthal fibers and eosinophilic granular bodies were observed. Hyalinized periodic acid-Schiff-positive vessels were widely separated. CD31 and CD34 revealed a sparse microvasculature. Tumor-associated exudate spread predominantly subretinally. The retinal pigment epithelium had undergone extensive placoid fibrous metaplasia with focal ossification. P53 upregulation, BRAF-KIAA gene rearrangement, and IDH1R132H mutation typically associated with low-grade astrocytic neoplasms were absent.

CONCLUSIONS

Retinal "vasoproliferative" tumors have been mischaracterized, because they actually display a paucity of microvessels. Proliferating fibrous astrocytes with a very low proliferation index predominate, without immunohistochemical or genetic evidence favoring a neoplasm. Subretinal exudate appeared capable of provoking widespread fibrous metaplasia of the pigment epithelium that was mainly responsible for secondary retinal damage. The term "reactive retinal astrocytic tumor" is proposed as more appropriate for this entity. In carefully selected progressive lesions, consideration should be given to earlier surgical intervention before extensive subretinal exudate accumulates and pigment epithelial proliferation with fibrous metaplasia ensues.

Familial bilateral combined hamartoma of retina and retinal pigment epithelium associated with neurofibromatosis 1

We report a family of three siblings followed between 2005 and 2011 with bilateral combined hamartoma of the retina and retinal pigment epithelium, with the age of diagnosis ranging from 7 to 13 years. The main reason for consultation was reduction of vision and squint. The diagnosis was determined based on the clinical findings on fundus examination: increased pigmentation at the macula with slightly elevated, gray-white macular lesion, tortuosity of perimacular blood vessels and glial epiretinal membrane. The elder brother was found to have left posterior subcapsular cataract. He was also confirmed to have neurofibromatosis type 1, the youngest sister fit in the diagnostic criteria for neurofibromatosis type 1, while the middle sister was presumed to have neurofibromatosis type 1. Follow-up showed stability of the retinal lesion in the three cases, with the progression to develop right posterior subcapsular cataract in the elder sister. This report is aimed to demonstrate that the occurrence of bilateral combined hamartoma of the retina and retinal pigment epithelium could raise the possibility of associated neurofibromatosis.