Simultaneous conjunctival intraepithelial neoplasia and primary pterygium – management using topical 0.02% mitomycin C

INTRODUCTION

Pterygium is an invasion of the cornea by the proliferation of abnormal subconjunctival tissue together with a chronic inflammatory reaction. Conjunctival intraepithelial neoplasia (CIN) contains dysplastic cells. Conjunctival epithelial malignancies have a close relation to pterygium, as various proteins are expressed similarly in both, and CIN can co-exist with pterygium.^[1] However, to the best of our knowledge, there are no reports currently showing evidence that CIN may arise from a primary pterygium itself or the adjacent tissue.

We present a rare case of CIN in conjunction with primary pterygium managed with topical mitomycin C.

DISCUSSION

A 27-year-old man presented with a mass lesion in his right eye for the last 2 months. On examination, the visual acuity in both eyes was 6/6. On slit-lamp examination, there was a pterygium and a whitish mass adjacent to it in his right eye and only a pterygium in the left eye. The lesion in the right eye showed characteristic feeder vessels adjacent to it. The rest of the ocular examination was within normal limits [Figure 1].

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Figure 1:

(a) Clinical image of right eye (OD); (b) left eye (OS).

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Figure 2 is the anterior segment optical coherence tomography (ASOCT) image of the right eye showing the size of the nasal lesion.

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Figure 2:

Anterior segment optical coherence tomography image of the right eye showing the size of the nasal lesion.

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Impression cytological examination of the mass lesion was done, and it showed features of mild dysplasia [Figure 3]. The patient was started on topical 0.02% mitomycin C eye drops 4 times a day-1 week on and 3 weeks off. After three cycles of this treatment, there was a marked reduction in the size and vascularity of the lesion.^[2,3]

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Figure 3:

Impression cytology image of mass lesion showing focal clusters of dysplastic cells in blood ( marked with black arrow). Stain: May-Grunwald Giemsaand magnification 40X.

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Figure 4 shows the clinical image and ASOCT of the right eye post three cycles of the treatment with reduced vascularity and size of the lesion.

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Figure 4:

Clinical image and anterior segment optical coherence tomography of the right eye post three cycles of the treatment with a reduced vascularity and size of the lesion. OD: Right eye

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CONCLUSION

CIN may have arisen from the primary pterygium or may have occurred de novo near the pterygium, subsequently inducing progression of the primary pterygium. In recent years, local chemotherapy with mitomycin C has been used as neoadjuvant therapy or as an alternative to surgical resection of CIN. There are multiple case series and individual cases demonstrating the use of topical mitomycin C for CIN with favorable results.

We showed a rare case of inflamed CIN arising from primary pterygium, which was treated with topical chemotherapy. Because CIN can occur adjacent to pterygial tissues, long-term follow-up is necessary in patients with pterygia.