Vitrectomy for Tractional Retinal Detachment Due to Combined Hamartoma of the Retina and Retinal Pigment Epithelium

Abstract

Purpose:

We discuss a peripheral combined hamartoma of the retina and retinal pigment epithelium (CHRRPE) with a macula-involving TRD that was repaired by vitrectomy surgery.

Methods:

A case report is presented.

Results:

A 15-year-old white girl with no significant medical or ocular history presented to the retina clinic with a 1-month history of progressive loss of inferior visual field in the right eye. A large, elevated CHRRPE was found in the superior midperipheral retina. On involvement of the macula, urgent vitrectomy surgery with peeling of the cortical vitreous membrane to the margins of the hamartoma was performed. Eighteen months later, vision had returned to 20/16 and the retina, relieved of traction, continued to reattach with trace remaining cystic changes at the fovea on optical coherence tomography.

Conclusions:

Physicians should consider vitrectomy surgery with membrane peeling of the cortical vitreous for TRD due to CHRRPE.

Introduction

Gass first applied the term combined hamartoma in 1973 to 7 patients with unusual pigmented retinal lesions. ¹ Combined hamartoma of the retina and retinal pigment epithelium (CHRRPE) is a rare, benign tumor of the neurosensory retina, retinal pigment epithelium (RPE), and, important in this case, adjacent vitreous. As described and classified by Dedania et al, CHRRPE is now recognized as a spectrum disorder based on lesion location, associated fundus findings, and optical coherence tomography (OCT) findings. ² We present a case of an advanced midperipheral CHRRPE with contiguous retinal, RPE, and vitreous involvement that created a combined retinoschisis and retinal detachment (RD).

Methods

Case Report

A 15-year-old girl with no ocular history presented with a “blank spot” in the visual field of her right eye; the blank spot was located inferior to central fixation and of 1 month’s duration. Visual acuity (VA) was 20/20 in both eyes. The left eye was normal. Dilated fundus examination of the right eye revealed a large, whitish-gray mass in the superior midperipheral retina overlying a larger area of greenish discoloration. B-scan ultrasonography confirmed this low-reflectivity mass to be the epicenter of a tractional RD (TRD) extending well into the macula but just short of the fovea. No tractional membranes were seen on B-scan (Figure 1). OCT demonstrated complete retina and RPE involvement with loss of normal retinal architecture, stretching of Müller cells due to large areas of schisis, and markedly elevated superior TRD. Importantly, there were no visible tractional membranes on OCT (Figure 2). The differential diagnosis included Toxocara canis, proliferative vitreoretinopathy from prior ocular trauma, inflammatory granuloma, retinoblastoma, and choroidal melanoma. Toxocara antibody titers were negative and there was no eosinophilia. There was no history of ocular trauma.

Figure 1.

(Left) Preoperative fundus photograph shows a large whitish-gray lesion with underlying greenish discoloration. Retinal corrugations are caused by the retinal detachment. No tractional membranes are seen. (Right) B-scan ultrasonography confirms tractional retinal detachment with intraretinal thickening due to the tumor. No tractional membranes are seen. RPR indicates rapid plasma reagin; FTA, fluorescent treponemal antibody; ACE, angiotensin-converting enzyme.

Figure 2.

(Left) Optical coherence tomography reveals tractional retinal detachment superior to and involving the fovea with loss of normal retinal architecture. No epiretinal membrane or tractional membranes are seen. (Right) Optical coherence tomography shows intraretinal cystic spaces and stretching of Müller cells. YO indicates year old; VA, visual acuity; OD, right eye.

Results from rapid plasma reagin, fluorescent treponemal antibody absorption, angiotensin-converting enzyme, and QuantiFERON-TB Gold tests (Qiagen) were all negative. Given the patient’s young age, lack of ocular inflammation, and normal test results, a clinical diagnosis of CHRRPE was made. Within 10 days of presentation, VA declined to 20/40 because of progressive RD through the fovea, prompting urgent surgery. Twenty-five–gauge vitrectomy was performed with peeling of the cortical vitreous membrane up to the edge of the hamartoma. There were no areas of spontaneous cortical vitreous separation from the retinal surface. Peeling was made difficult by the thin retina owing to chronic retinoschisis. Additional anterior-posterior vitreal membranes were also removed with the vitrectomy probe. Importantly, no separate epiretinal membrane (ERM) was seen or peeled. There was no excision of the tumor. With 18 months of follow-up, the retina gradually reattached, and VA returned to 20/20 with trace remaining cystic changes at the fovea on OCT and near complete resolution of the inferior scotoma (Figure 3).

Figure 3.

One-year postoperative fundus photograph showing retinal reattachment and a white, fibrotic combined hamartoma of the retina and retinal pigment epithelium, which is segmented from surrounding cortical vitreous.

Results

Our case describes a zone 2, stage 3C CHRRPE presenting as peripheral visual field loss in an otherwise healthy 15-year-old girl. The peripheral location of the tumor likely explains the older age of the patient and the advanced stage of disease at presentation. ² Of note, this patient had never received a dilated retinal examination. In addition, there was no history of neurofibromatosis type 1 or type 2.

An interesting feature of this case is the rapid progression of the TRD after presentation. VA fell from 20/16 at baseline with an attached fovea on OCT to 20/40 with a detached fovea within 10 days. Frequent OCT testing documented elevation of the retina progressively worsening in 50- to 100-µm increments. Thus, the progression was rapid.

Possible surgical interventions to repair the TRD from CHRRPE included vitrectomy with scleral buckle procedure, vitrectomy with excision of the tumor and silicone oil tamponade, and vitrectomy with membrane peeling, presumably of ERMs. Although no ERMs or other tractional membranes were identified on preoperative clinical examination, B-scan ultrasonography, or spectral-domain OCT, intraoperative findings revealed definite anterior-posterior vitreal membranes attaching to the tumor surface and transverse traction from the cortical vitreous membrane. The surgical objective was the successful peeling of vitreal membranes, not peeling of reactive gliosis or other epiretinal proliferation. The case was made difficult by an underlying thin, atrophic retina due to chronic retinoschisis and RD. No retinal breaks were incurred. No ocular tamponade was needed to achieve retinal reattachment. Postoperatively, retinal settling occurred gradually over many months and could be reliably tracked with OCT.

Conclusions

Several authors have described surgical outcomes of ERMs associated with CHRRPE. ^{3 -6} In these limited case series dating back to 2010 or earlier, it is unclear whether the authors were referring to classic epiretinal proliferation or reactive glial/fibrous tissue. With the advent of spectral-domain OCT and other improved imaging modalities, classic ERMs can now be easily identified. We report the surgical management of an advanced-stage CHRRPE characterized by retinoschisis and progressive TRD. Preoperatively, no classic ERMs nor even vitreal traction membranes were seen on clinical examination, fundus photography, ultrasonography, or spectral-domain OCT. Intraoperatively, anterior-posterior vitreous membranes as well as transverse cortical vitreous traction were evident. Straightforward, 25-gauge vitrectomy with peeling of vitreous tractional membranes and avoidance of retinal breaks resulted in gradual retinal reattachment and improved VA. Clinicians should consider vitreous tractional membranes rather than preretinal gliosis/fibrous proliferation as contributing to the underlying pathology of CHRRPE.