BACKGROUND: Conjunctival squamous cell carcinoma in situ, or intraepithelial neoplasia (CIN), is a rare slow-growing tumor of the conjunctival epithelium typically seen in older, fair-skinned individuals. Carcinoma in situ microscopically exhibits epithelial changes similar to those seen in squamous cell carcinoma but is differentiated from invasive squamous cell carcinoma by an intact subepithelial basement membrane. This intact basement membrane confines the tumor to the conjunctival epithelial layer, thereby, separating the epithelium and tumor from the underlying substania propria or stroma. The lesion is a vascularized, gelatinous thickening of the conjunctiva most frequently arising at the limbus and may extend onto the cornea. The etiology is unknown but probably multifactorial. There is an increased risk with a history of UV light exposure, which may promote neoplastic transformation of susceptible cells, most likely limbal stem cells. Squamous cell carcinoma in situ and squamous cell carcinoma have also been associated with the human papillomavirus (HPV) and HIV. Recurrence can be minimized by complete excision.
CASE REPORT(S). A 37 year old Caucasian female presented to our clinic complaining of a "red spot" and "ache" in her left eye for the past 4 months. She was initially diagnosed with pingueculitis and treated with topical corticosteroid, which improved the condition. After discontinuing the medication, the lesion would become inflamed again. The lesion was excised and biopsied. The histopathologic examination diagnosed squamous cell carcinoma in situ. Photographs of the lesion and histopathology report will be presented along with possible differential diagnoses and management.
CONCLUSIONS. Squamous cell carcinoma in situ is an important differential diagnosis for any persistent ocular lesion. Appropriate diagnosis and management is imperative to minimize recurrence and progression.