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CASE REPORT
Year : 2023 | Volume
: 30
| Issue : 1 | Page : 81-84
Bilateral astrocytic hamartoma with vasoproliferative tumour in retinitis pigmentosa
Yewande O Babalola1, Miloni S Shah2, Srikant K Padhy2, Umesh C Behera2
1 Retina and Vitreous Services, LV Prasad Eye Institute, Mithu Tulsi Chanri Campus, Bhubaneshwar, India; Department of Ophthalmology, University College Hospital, Ibadan, Nigeria
2 Retina and Vitreous Services, LV Prasad Eye Institute, Mithu Tulsi Chanri Campus, Bhubaneshwar, India
Correspondence Address:
Yewande O Babalola
Department of Ophthalmology, University College Hospital, Ibadan
Nigeria
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/npmj.npmj_265_22
We report a rare case of a 32-year-old Indian male who presented to the retina outpatient department with a history of sudden worsening of vision in the left eye. There was a background history of poor vision and deficient night vision since childhood. At the first presentation, the best corrected visual acuity was 6/36 and 6/60 in the right and left eye, respectively. Ocular examination revealed waxy pale disc, bone spicule pigmentation, attenuated vessels and epiretinal membrane in the right eye in keeping with retinitis pigmentosa. An astrocytic harmatoma was also present in the right eye. Vitreous haemorrhage in the left eye precluded a view of the fundus. He subsequently had a left pars plana vitrectomy, and intravitreal bevacizumab on account of non-resolving vitreous haemorrhage and a vasoproliferative tumour and astrocytic hamartoma were noticed intraoperatively. He had a good immediate post-operative outcome post-left vitrectomy but subsequently developed left neovascular glaucoma 2 years after. Neovascular glaucoma may be a sequela of vasoproliferative tumour; hence, regular follow-up and monitoring are essential in these patients.
Keywords: Astrocytic hamartoma, neovascular glaucoma, retinitis pigmentosa, vasoproliferative tumour, vitreous haemorrhage
Retinitis pigmentosa (RP) has been associated with various ocular pathologies such as posterior subcapsular cataract, glaucoma, keratoconus, myopia, optic nerve drusen and vitreous opacities amongst other lesions.[1],[2] Tumours associated with RP more commonly include vasoproliferative tumours though isolated astrocytic hamartomas have been described.[3],[4],[5] Open-angle glaucoma in RP with a prevalence ranging from 2% to 12% is common, while angle closure with a prevalence of about 2% may also occur.[6]
There are few reports of neovascular glaucoma occurring in RP, with retinal neovascularisation being the antecedent.[7] A case of bilateral neovascular glaucoma in a diabetic patient with RP and the absence of neovascularisation of the retina has been reported.[8] Inverse RP has also been described in occurrence with neovascular glaucoma.[9] Hypotheses that have been propounded for these events include inflammation from damage to photoreceptors and pre-existing vaso-occlusive events. Non-perfusion of retinal capillaries and alterations in the milieu of the retinal vasculature are also propounded factors.[7],[8],[10] The index patient was a rare case of left astrocytic hamartoma and vasoproliferative tumour associated with RP with subsequent development of left neovascular glaucoma.
Case ReportA 32-year-old Indian farmer presented to the retinal clinic with a deterioration of vision in his left eye of a months' duration. He gave a background history of poor night vision since childhood. At presentation, the best-corrected visual acuity (BCVA) at presentation was 6/36 and 6/60, respectively, in the right and left eye. The anterior segment examination was unremarkable except for bilateral early posterior subcapsular cataracts. Binocular indirect ophthalmoscopy of the right eye revealed waxy disc pallor, widespread bony spicule pigments and arterial attenuation with soft, glistening, mulberry-like yellowish lesions, characteristic of astrocytic hamartoma in the nasal peripapillary region [Figure 1]. The fundal details in the left eye were obscured by vitreous haemorrhage. The intraocular pressures (IOPs) by Goldmann applanation tonometry were 16 mmHg and 17 mmHg, respectively, in the right and left eye.
Figure 1: Is a montage fundus photograph of the right eye with bone spicule pigmentation, attenuated vessels and peripapillary astrocytic harmatoma (black arrow)The left vitreous haemorrhage was non-resolving after a month of conservative management; hence the patient was scheduled for left pars plana vitrectomy. Intraoperatively, a dense vitreous haemorrhage consisting of fresh and altered blood was noted and cleared, along with the thick adherent posterior hyaloid. A yellow, glistening cluster of mulberry lesions typical of astrocytic harmatoma was seen inferonasal to the disc and an elevated, bright pink lesion measuring about 1.5–2 disc diameters (DDs) suggestive of retinal vasoproliferative tumour (VPT) was present in the inferior periphery at 6' o clock [Figure 2]. Intravitreal bevacizumab (1.25 mg) injection was given in the left eye to reduce tumour vascularity. Postoperatively, there was tumour regression and vision improved to 6/36 in the left eye.
Figure 2: Is a montage fundus photograph of the left eye showing mulberry-like parapapillary astrocytic harmatoma (black arrow), blood stained, pink vasoproliferative tumour in the inferior periphery (black arrowhead) bony spicule pigmentation, attenuated vessels and chorioretinal atrophy more marked in the mid peripheryThe bilateral peripapillary, mulberry lesions showed hyper-echogenic masses on B-mode echography and high echo spikes on A-scan. Optical coherence tomography revealed internal vacuolations in both eyes, signs which are pathognomonic for astrocytic hamartoma [Figure 3]. Epiretinal membranes were present bilaterally. Detailed examination and clinical evaluation of the central nervous, cardiac, abdomen and respiratory systems were found to be essentially normal, with the absence of clinical features associated with syndromic RP. Features of phacomatosis, such as tuberous sclerosis and neurofibromatosis commonly associated with astrocytic hamartomas, were also absent after a detailed systemic examination. Rinne and Weber's test done were normal and ruled out the presence of a hearing defect. There was no history of consanguinity. A diagnosis of RP with bilateral astrocytic hamartoma and a left vasoproliferative tumour was made.
Figure 3: (a) shows bright hyperautofluorescence of the astrocytic hamartoma cluster inferonasal to the disc in the left eye while (b) is the ocular B-scan ultrasonography showing hyperechoic lesions of the left astrocytic harmatoma. (c) is the optical coherence tomography scan of the lesion showing hyperreflectivity of the inner border of the tumour in the left eye with homogenous internal hyporeflectivity suggestive of vacuolationOne month postoperatively, the BCVA in the left eye was 6/36. The VPT showed signs of regression; however, the IOP was noticed to be elevated and measured 23 and 25 mmHg in the right and left eye, respectively. On examination, the cup-to-disc ratio was 0.3 in both eyes with open anterior chamber angles and no evidence of neovascularisation on gonioscopy. Fluorescein angiography was done, which showed tumour regression of the VPT with normal retina perfusion. The IOP in the left eye was controlled with anti-glaucoma medication timolol for over a year. The low vision was attributable to the background RP, epiretinal membrane and posterior subcapsular cataracts.
The patient defaulted from follow-up for 2 years and re-presented after the COVID-19 pandemic lockdown with a painful, blind left eye. The BCVA was no light perception with a complicated cataract, 360° posterior synechiae, extensive-angle neovascularisation and rubeosis iridis in the left eye. The IOP was 35mmHg. He was given a referral to the physician for systemic evaluation and investigations to rule out possible ischaemic conditions such as diabetes mellitus, hypertension, dyslipidaemia, cardiac disease, leukaemia and collagen vascular disease, which would be risk factors for the development of neovascular glaucoma. None of these systemic conditions were present and all investigations were within the normal limits. The patient was adequately counselled on the various treatment options for the painful blind left eye and eventually decided on the evisceration of the painful, blind eye. Histopathology of the eviscerated left eye was not done and the post-operative period for the evisceration was uneventful.
The right eye with only an astrocytic hamartoma and background RP without VPT remained stable with BCVA of 6/36 and the patient was commenced on the use of low vision aids. There was no sign of neovascular complications clinically in the right eye though fundus fluorescein angiography was not repeated. The IOP remained within normal limits in the right eye. The astrocytic hamartoma on the disc also remained stable with no morphological change as at the last follow-up visit.
DiscussionVPTs have been classified as primary or secondary. Primary VPT has no predisposing eye disease, while secondary VPT occurs in the presence of pre-existing primary eye disease. In a large series, the incidence of secondary VPT in RP was approximately 22%.[3],[11] Younger individuals, patients with visual acuity <6/60, bilaterality and multifocality of tumours are some of the features classified as being characteristic of a secondary VPT.[11] These tumours may be associated with the presence of intraretinal or subretinal exudation, epiretinal membrane, retinoschisis, retinal detachment, vitreous haemorrhage and retinal neovascularisation.[11],[12] Vitreous haemorrhage, posterior subcapsular cataracts and epiretinal membranes were present in this index patient though the tumour was unilateral and also unifocal. VPT is pink-yellow, dome-shaped lesions lacking feeder vessels often found in the pre-equatorial region with a predilection for the inferotemporal peripheral retina.[12] The VPT in our patient met these criteria as it was situated at 6 o'clock in the pre-equatorial area with the absence of feeder vessels. It has been documented that peripheral VPT may have an effect on visual function due to epiretinal membranes on the macula.[11] This index patient had bilateral epiretinal membranes, most likely in association with the underlying RP.[11],[13]
Bilateral astrocytic hamartomas have previously been documented in patients with RP.[4],[14],[15] As astrocytic hamartomas are associated with neurocutaneous syndromes such as tuberous sclerosis, a detailed systemic and clinical evaluation was done for our patient and was normal. VPT co-existing with astrocytic harmatomas in RP is rare and to the best of our knowledge, this may be the first report. The vitreous haemorrhage was responsible for the acute deterioration in the vision of the left eye at presentation and was the indication for pars plana vitrectomy. Similar cases of vitreous haemorrhage occurring in RP secondary to neovascularisation and subsequently treated with pars plana vitrectomy have been reported.[7],[16]
VPT and astrocytic hamartomas are thought to have a common histological origin. Features of pilocytic hamartoma with microvasculature features are present in VPT. Histologically, VPT are reactive glial proliferations and vascular endothelial growth factor (VEGF) plays an important role in its formation.[5],[17] Several treatment modalities, namely laser photocoagulation, photodynamic therapy, cryotherapy, plaque radiotherapy, local resection and the use of anti- VEGF have been suggested.[11],[12],[18],[19],[20] The index patient was managed with pars plana vitrectomy for the non-resolving vitreous haemorrhage and intravitreal bevacizumab for the VPT with a good initial response.[15] It has been reported that small tumours up to 2 DDs, respond well to a single injection of intravitreal bevacizumab with complete regression of the tumour.[19],[20]
Optic nerve drusen were considered a differential for the astrocytic hamartoma and were ruled out as the hamartomas were obviously distinct from the optic nerve head with the absence of blurring of the disc margins. The gradual transition of the astrocytic harmatoma from the normal retina to hyporeflective areas of vacuolation with disorganisation of the retinal layers aided in clinching the diagnosis.[21] VPT was differentiated from similar entities like presumed solitary circumscribed retinal astrocytic proliferation, which is usually a unilateral, solitary, benign lesion with no calcification and are non-progressive in nature. Retinal capillary haemangiomas were also ruled out as a possible differential due to the absence of feeder or tortuous vessels. Clinical features of Von Hippel-Lindau syndrome were also not present in our index patient.
Increasing IOPs were observed a few months postoperatively and were managed with anti-glaucoma medications for over a year, with the VPT and other ocular findings being stable over this follow-up period. Gonioscopy revealed open angles in both eyes. Nevertheless, open-angle glaucoma is a known association of RP and is not an unusual occurrence.[22] The patient defaulted from follow-up for about 2 years prompted in part by the country-wide lockdown in India due to the COVID-19 pandemic and subsequently presented with features of neovascular glaucoma and a painful blind eye.
A possible reactivation of the VPT, might have led to the increasing VEGF. Such occurrences have been reported in the literature and successfully managed with laser pan-retinal photocoagulation, cryotherapy and intracameral bevacizumab, an anti- VEGFs with good visual outcomes.[7],[8],[9] This reactivation may have been promptly diagnosed and managed if the patient had presented to the hospital promptly.
In conclusion, astrocytic hamartomas and vasoproliferative tumour may coexist in RP. Vasoproliferative tumours may be vision-threatening and lead to sequelae of neovascular glaucoma and a painful, blind eye. Prompt diagnosis and management of these lesions with adequate follow-up are fundamental in preventing this dire complication.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
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Conflicts of interest
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References
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