Delayed Pediatric Diagnosis of Cysticercosis and Uveitis Presenting as Chronic Multifocal Subretinal Fluid Blebs

Abstract

Purpose:

To report an unusual case of intraocular cysticercosis in a 11-year-old boy that presented with chronic posterior uveitis and associated recalcitrant subfoveal and multifocal subretinal fluid blebs. The patient was later found to have a subsequent free-floating vitreous cyst that had been concealed from examination for years.

Methods:

Case report.

Results:

A diagnostic and therapeutic vitrectomy and cyst extraction revealed eosinophilic material suggestive of cysticercosis. Brain magnetic resonance imaging revealed suggestive neurocysticercosis and serological titers for cysticercosis immunoglobulin G were positive. After antihelminthic therapy and surgical removal of the cyst, the patient did well with complete resolution of multifocal subretinal fluid blebs and visual acuity improvement to 20/25.

Conclusion:

Ocular cysticercosis is a sight-threatening parasitic disease that can cause visually threatening manifestations if not identified and treated in a timely manner. Awareness of atypical presentations such as seen in this case in a pediatric patient is paramount.

Introduction

Cysticercosis is a common parasitic infection caused by the larvae cysts of the pork tapeworm, Taenia solium. It is commonly caused by the ingestion of T solium eggs from contaminated food or water. ¹ After the larvae penetrate the intestinal wall, they invade the bloodstream and various organs, including the brain, skeletal muscle, and eye. ²

Ocular cysticercosis has a varied clinical presentation depending on the area of invasion, number of lesions, and host immune response, which may pose a diagnostic challenge to doctors. ³ The cyst can invade any location within the eye, including the vitreous humor, subretinal tissue, and extraocular muscles, with the posterior segment being the most common. ⁴ The presence of intraocular cysticercosis is associated with severe intraocular inflammation and visual debilitation. Diagnostic delay is an established risk factor for poor outcomes. ^2,3 Therefore, early recognition with proper medical and surgical management is crucial for preventing vision loss and optimizing outcomes. In this report, we present an unusual case that lacks many of the classic findings associated with intraocular cysticercosis. We also review the literature on the manifestations of cysticercosis, updating its presentation based on the present case.

Methods

Case Report

An 8-year-old boy in Michigan with a medical history of asthma and Tourette syndrome presented initially in 2017 with sudden-onset vision loss in the right eye following blunt ocular trauma by a ball. He was diagnosed and followed by an outside academic institution for Berlin edema and posttraumatic, noninfectious uveitis. Initial imaging showed nonleaking chronic subfoveal fluid. The patient improved after undergoing oral prednisone pulse therapy and was subsequently bridged to methotrexate. Owing to elevated liver enzymes, his immunomodulatory therapy was transitioned early on to mycophenolate mofetil. He developed a posterior subcapsular cataract and underwent cataract extraction with intraocular lens placement in 2019.

The patient continued to have chronic posterior uveitis and recalcitrant subfoveal fluid for years and was referred for a second opinion. On initial examination at age 11 years, the patient had a long-standing best-corrected visual acuity of 20/200 OD and 20/20 OS. Examination of the right eye showed diffuse iris atrophy with secondary heterochromia, low-grade vitritis, and multifocal subretinal fluid (SRF) blebs involving the macula and periphery. Spectral-domain optical coherence tomography scan revealed chronic subfoveal and peripheral macular fluid blebs (Figure 1). Widefield fundus photography confirmed the distribution of the multifocal SRF blebs involving both the posterior and peripheral retina. Widefield fluorescein angiography revealed diffuse peripheral leakage, optic disc hyperfluorescence, and lack of fluorescence within the SRF blebs (Figure 2). Ultrasound biomicroscopy of the anterior segment was otherwise unremarkable.

Figure 1.

(A) Optical coherence tomography of the right eye reveals subfoveal fluid (asterisk). (B) En face frontal section optical coherence tomography reveals additional peripheral blebs (arrows).

Figure 2.

(A) Widefield fundus photography displaying the distribution of the multifocal SRF blebs (arrows). (B) Widefield fluorescein angiography demonstrates diffuse peripheral leakage and absence of hyperfluorescence in the SRF blebs in late frames.

The patient had an unremarkable serology workup whose results included a mildly elevated but age-appropriate angiotensin-converting enzyme, negative testing for tuberculosis, and absence of antibodies to toxoplasmosis and bartonella. Complete blood count showed a normal eosinophil count. Owing to concern for infectious uveitis, the patient underwent an examination under anesthesia with a diagnostic anterior chamber paracentesis of which polymerase chain reaction analysis returned negative for viral culture, varicella-zoster virus, herpes simplex virus, and cytomegalovirus. For subsequent months, the multifocal SRF blebs persisted despite trials of oral prednisone, acetazolamide, and intravitreal triamcinolone until spontaneous resolution of intraocular inflammation occurred with associated collapse of all multifocal neurosensory retinal detachments. At that time, a newly presenting free-floating inferior vitreous cyst was visualized (Figure 3). On further examination of his history, it was revealed that the patient had a pet pig and frequently visited a family farm in New York, where he interacted with multiple potbellied pigs. Given this exposure to pigs, the possibility of intraocular cysticercosis was raised. Accordingly, the patient was prescribed oral albendazole twice per day (15 mg/kg/d) for 30 days and underwent vitrectomy and en bloc cyst extraction.

Figure 3.

(A) Widefield fundus photography shows a characteristic free-floating vitreous cyst. (B) External surgical photograph and (C) intraoperative optical coherence tomography of the externalized cyst.

A pathology report revealed a degenerating cyst lined with eosinophilic material composed of loose stroma, erythrocytes, and foreign-body material. Brain magnetic resonance imaging revealed a 3.5-mm cystic focus in the anterior subdural space along the falx suggestive of neurocysticercosis in the vesicular stage. Serological titers for cysticercosis (T solium) immunoglobulin G returned positive results.

Results

The patient continued to do well postoperatively, with complete resolution of SRF blebs and intraocular inflammation following cessation of mycophenolate mofetil, and visual acuity has since improved to 20/25.

Conclusions

In this report, we described an unusual case of intraocular cysticercosis associated with chronic posterior uveitis and recalcitrant multifocal, nonleaking SRF blebs despite years of immunomodulatory therapy. After a characteristic cyst was subsequently released into the vitreous after being concealed from examination for years, the patient was prescribed a therapeutic trial of antihelminthic drugs and underwent cyst extraction. Pathology revealed a degenerating cyst lined with eosinophilic material suggestive of cysticercosis. Intraoperative optical coherence tomography of the externalized cyst was significant for both outer and inner hyperreflective walls.

This unusual presentation should be recognized and added to the ocular manifestations of cysticercosis. Following the initial trauma, the patient developed persistent intraocular inflammation. The delayed release of the clear cyst into the vitreous cavity after being concealed from examination angles for years in addition to early-onset iris pigment loss and cataract development suggested a chronic anterior inner wall attachment with delayed release into the vitreous. Prior ultrasound biomicroscopy was unremarkable; however, it may have been limited in a pediatric patient in a clinical setting. The subsequent free-floating form was associated with dramatic improvement in intraocular inflammation and complete resolution of the SRF blebs. It may be hypothesized that this release was associated with life cycle changes of T solium, and the adherence to inner wall structures was more inflammatory compared with the free-floating form in the vitreous.

Any structure of the eye can be affected by intraocular cysticercosis in varying presentations; however, posterior segment involvement is the most common and vision threatening. ⁵ The standard treatment of intraocular cysticercosis is complete surgical removal. In addition, antihelminthic therapy is generally indicated for live infections in multiple sites with concomitant steroids to mitigate the provoked inflammatory response. While intravitreal cysticercosis has been shown to reach the vitreous cavity by perforating the retina, the present case had no suggestion of prior subretinal or choroidal involvement by T solium. ⁴ In addition, reported cases of serous macular-off detachments have been strongly associated with a cyst in the subretinal space. ⁵

The present case highlights the importance of recognizing this unique presentation given the presence of concomitant neurocysticercosis found in the viable parasitic vesicular stage in a pediatric patient.