SUB-CONJUNCTIVAL CYSTICERCOUS CYST

SUB-CONJUNCTIVAL CYSTICERCOUS CYST

RAKESH BAROT*, NAMRATA MANGLANI*, MADHURI PATTIWAR**
*Lecturer; **Associate Professor, Department of Ophthalmology, Rajiv Gandhi Medical College and Chhatrapati Shivaji Maharaj Hospital, Kalwa, Thane 400 605.

INTRODUCTION

Cysticercosis is the infestation by Cysticercus cellulosae, the larval form of the pork tape worm, Taenia solium. It is contracted by (a) Ingestion of infective cysticerci in under-cooked pork; (b) Ingestion of eggs of T. solium in contaminated water, food or vegetables; and (c) Regurgitation of eggs from the small intestine.[1] The sites for predilection for the development of cysticerci are the Central Nervous System (CNS), sub-cutaneous tissue, skeletal muscles, the heart muscle and the eye.[2] Ocular involvement occurs in 13-46% of infected patients. Ocular cysticercosis is common in the Indian sub-continent.[3]

We report a case of sub-conjunctival cysticercous cyst in a tribal boy hailing from Thane district in Maharashtra State.

CASE REPORT

A 13 year old averagely built school boy, a non-pork eater, presented with a gradually progressive swelling in the right eye. He was a tribal boy belonging to low socio-economic group. The duration of the swelling was over two months. He complained of "watering" of the eye and discomfort on closing the eye lids. He did not give a history of headache and seizures.

On examination, the right eye showed a pinkish, smooth, horizontally oval (elliptical), sub-conjunctival swelling measuring 10 mm x 8 mm, near the inner canthus (Fig. 1). The outer border of the swelling was 2 mm away from the plica semilunaris. On closing the right eye lids, the cyst protruded from the eye.

The conjunctiva over the swelling showed keratinization and congested blood vessels. The swelling was slightly tender, non-reducible and loosely attached to the eye ball. The patient's visual acuity was 6/6 in both eyes. His extra-ocular movements were normal in cardinal positions of gaze. The left eye did not reveal any abnormality. On systemic examination, sub-cutaneous nodules were absent.

B-Scan Ultrasonography (USG) of the right eye and orbit, which was done two weeks later, demonstrated a complete, thick-walled sub-conjunctival cyst on the antero-medial aspect, measuring 11.0 mm x 7.8 mm x 6.0 mm (Fig. 2). It showed an eccentric high-reflective opacity, suggesting a scolex and low-reflective mobile opacities filling the cyst cavity.

Fig. 1: Rt eye showing smooth, horizontally oval subconjunctival swelling.

Fig. 2: Appearance on B-scan USG.

Complete blood count (CBC) and erythrocyte sedimentation rate (ESR) were normal. Repeated stool samples did not show any proglottids or eggs of T. solium. USG of abdomen and plain radiographs of the skull were normal.

Excisional biopsy of the cyst was done under local anaesthesia. The gap in the conjunctiva was sutured and the post-operative period was uneventful.

On gross examination, the cyst was found to be smooth, thick-walled and brownish in colour, measuring 14 mm x 11 mm x 7 mm. It had a smooth internal lining membrane. Its lumen contained a colourless fluid and a chalky white spot in the eccentric position, suggesting a scolex.

Histopathological examination showed that the body canal of the cysticercus cellulosae was lined by cuboidal epithelium and surrounded by fibrous tissue and inflammatory infiltrate comprising lymphocytes, plasma cells, eosinophils, neutrophils and foreign body giant cells (Fig. 3).

Fig. 3: Histopathological appearance.

A diagnosis of sub-conjunctival cysticercous cyst was made on the basis of clinical examination, B-Scan USG and histopathology reports.

DISCUSSION

Ocular dissemination of cysticercus cellulosae is well known. Sommering[4] first reported a case of ocular cysticercosis in the year 1830. Since then, several reports have appeared in medical literature. In the eye, the most favoured site for cysticercus cellulosae is the vitreous and sub-retinal space, followed by the sub-conjunctival tissue.[5,6] In the conjunctiva, it usually presents as sub-conjunctival cyst and in rare instances, as a sub-conjunctival abscess. According to Nath et al,[7] incidence of sub-conjunctival cysticercous cysts among the cystic lesions of the conjunctiva was 8.89%. It has been reported that the left eye and the medial aspect of the ocular and orbital regions are more prone to infestation by this parasite, due to anatomical reasons.[3,8] However, in the present case, the medical aspect of the right eye was involved. Several reports of spontaneous expulsion or partial prolapse of sub-conjunctival cysticercous cysts have been published.[9] There were no such signs in the present case.

Our patient was a non-pork eater and the relevant investigations ruled out intestinal infestation. This emphasizes the need for appropriate measures to ensure food sanitation and personal hygiene in controlling this parasitic disease.[1]

REFERENCES

1.Park K. "Park's Text Book of Preventive and Social Medicine". 15th edition. Banarsidas Bhanot, Jabalpur. 1997; 230-31.

2.Ryan SJ. Ocular Cysticercosis : Retina. Second edition CV Mosby and Co, St. Louis (USA), 1994; 2 : 1553-57.

3.Malik SRK, Gupta AK, Chowdhary S. Ocular Cysticercosis. American Journal of Ophthalmology 1968; 66 : 1168-71.

4.Duke-Elder S. System of Ophthalmology. Henry Kimpton, London. 1976; XV : 40.

5.Duke-Elder S. System of Ophthalmology. Henry Kimpton, London. 1965; XV : 423.

6.Bartholomew RS. Sub-retinal Cysticercosis. American Journal of Ophthalmology 1975; 75 : 670.

7.Nath K, Gogi R, Zaidi N, Johri A. Cystic lesions of conjunctiva (A clinico-pathological study). Indian J Ophthalmology 1983; 31 (1) : 1-4.

8.Sen DK, Mathur RN, Thomas A. Ocular cysticercosis in India. British J Ophthalmology 1967; 51 : 630.

9.Bansal RK, Gupta A, Grewal SP, Mohan K. Spontaneous extrusion of cysticercous cysts - Report of 3 cases. Indian J Ophthalmology 1992; 40 (2) : 59-60.

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