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Lesion incidentally found during epiphora evaluation
Examination of the right eye revealed an irregular lesion near the limbus with abnormal vessels and adjacent corneal leukoplakia.
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An 81-year-old woman was referred for evaluation of epiphora in the left eye and was incidentally found to have an abnormal lesion in the right eye. She had a history of a temporal pinguecula in the right eye and a nasal pinguecula in the left eye, with episodic pingueculitis in the left eye. Fifteen months before presentation in our clinic, the patient described that this “early pterygium” had developed temporally in the right eye. Stability was noted on exam 1 year later. She denied any irritation, pain or ocular symptoms in the right eye.
Her medical history was remarkable for a left parotid gland mass that was later found to be poorly differentiated adenocarcinoma, for which she underwent treatment with surgical excision and chemotherapy. Her ocular history was otherwise significant for cataracts, posterior vitreous detachments and dry age-related macular degeneration in both eyes.
Examination
On examination, the patient’s uncorrected vision was 20/40 in the right eye and 20/30 in the left eye. Her pupils were equal, round and reactive. Her anterior segment exam was remarkable for meibomian gland dysfunction, lid laxity and moderate nuclear sclerosis in both eyes. Examination of the conjunctiva of the right eye revealed an irregular 4 mm × 4 mm lesion near the limbus at 9 o’clock with abnormal vessels and adjacent corneal leukoplakia extending 3 mm onto the temporal cornea (Figure 1). Dilated fundus exam was unremarkable bilaterally.
Figure 1. Slit lamp photos revealing temporal conjunctival lesion with abnormal limbal vessels and adjacent corneal leukoplakia in the right eye.
Images: Muakkassa N, Rao NK
What is your diagnosis?
Irregular lesion
The differential diagnosis of an incidentally noted conjunctival and corneal lesion in an elderly woman includes malignant tumors such as ocular surface squamous neoplasia, mucoepidermoid carcinoma and amelanotic melanoma, as well as benign lesions such as pterygium and sessile squamous papilloma.
Ocular surface squamous neoplasia (OSSN) includes a spectrum of pathologies from conjunctival intraepithelial neoplasia to invasive squamous cell carcinoma. Lesions may be conjunctival, limbal or corneal and are typically classified as leukoplakic, gelatinous or papillomatous.
Mucoepidermoid carcinoma is a malignant squamous neoplasia that is highly aggressive and often requires enucleation or exenteration. Amelanotic melanoma is typically a nonpigmented limbal lesion and can be mistaken for surface squamous neoplasia. These two pathologies should be kept in mind when evaluating atypical ocular surface lesions. Definitive diagnosis is made by excisional biopsy.
Pterygia are typically wing-shaped, fibrovascular lesions arising from the nasal conjunctiva and extending onto the cornea. Temporal pterygia are less common than nasal pterygia. Squamous papillomas are benign neoplastic lesions associated with human papillomavirus (HPV) and can appear similar to OSSN.
Diagnosis and management
Given the atypical location, irregular borders and abnormal vessels, an excisional biopsy was performed. A 7 mm × 4 mm area of conjunctiva was excised. The procedure included application of absolute alcohol to the sclera, superficial keratectomy of the involved cornea and double-freeze-thaw cryotherapy to the limbus and conjunctival edges. The conjunctiva was secured to the sclera using interrupted 8-0 Vicryl sutures, leaving an area of bare sclera to allow for close postoperative observation of the biopsied region for recurrence. Pathologic examination revealed squamous cell carcinoma in situ of the corneal and limbal scrapings (Figure 2), as well as moderate dysplasia overlying solar elastosis of the conjunctiva (Figure 3). The use of interferon alpha-2b was recommended to the patient, but she elected observation. Follow-up examination 3 weeks after excision revealed no evidence of recurrence (Figure 4). Two months after excision, the conjunctiva had fully healed. The temporal area of bare sclera had epithelialized and revascularized. There continued to be no sign of recurrence of the tumor.
Figure 2. Hematoxylin and eosin stain of the limbal and corneal scrapings revealing squamous cell carcinoma in situ.
Figure 3. Hematoxylin and eosin stain of the conjunctival specimen revealing moderate epithelial dysplasia overlying solar elastosis.
Figure 4. Slit lamp photos 3 weeks after excisional biopsy with cryotherapy.
Discussion
Providers should maintain high suspicion of OSSN or other malignant tumors in atypical-appearing ocular surface lesions, particularly in older patients. Atypical features include abnormal vasculature, feeder or corkscrew vessels, and corneal extension. Pterygia with unusual features should be closely monitored, and if there is cause for suspicion, excisional biopsy should be performed.
Risk factors for OSSN include age, ultraviolet light exposure, smoking, HPV 16 or 18, xeroderma pigmentosum and immunosuppression. Pathologic findings include hyperplasia, loss of goblet cells, nuclear hyperchromasia, mitotic figures and chronic inflammation of the substantia propria. In squamous cell carcinoma, there is invasion through the basement membrane into the substantia propria.
Management is typically excision with or without adjuvant cryotherapy or topical chemotherapy. Excision alone has a 17% to 52% recurrence rate, while excision with adjuvant cryotherapy has a significantly lower recurrence rate of 4% to 16%. Primary or adjuvant topical chemotherapy with interferon alpha-2b, mitomycin C or 5-fluorouracil has been investigated. Primary topical chemotherapy alone has a wide range of reported recurrence rates. Advantages of primary topical chemotherapy include a lower risk of limbal stem cell deficiency and treatment of clinically normal but dysplastic areas; however, it leaves patients without a histological diagnosis. Further studies with longer follow-up periods are needed to determine the best treatment options for patients with OSSN. Patients require at least annual lifelong follow-up to monitor for recurrence.