Introduction
Ocular surface squamous neoplasia (OSSN) is an umbrella of diseases involving an abnormal growth of squamous epithelial cells. Presentation varies but OSSN often appears within the interpalpebral region where ultraviolet (UV) exposure is highest. It can be described as a fleshy, gelatinous mass with neovascularization occurring near the limbus. Common differentials include pingueculitis, nodular conjunctivitis, and episcleritis. Clinicians should have a degree of suspicion while assessing these types of ocular lesions. The diagnostic gold standard historically has been a histopathological evaluation with a biopsy. Now, anterior segment optical coherence tomography (AS-OCT) has become a mainstream approach to diagnosing the condition due to its wide accessibility. When examined with ultrahigh resolution, key features to differentiate lesions include areas of hyper-reflectivity, thickened epithelium, and abrupt transitions from normal to abnormal tissue.
Prevalence is highest in the middle-age to elderly population with a slightly higher occurrence in men. Risk factors for OSSN include UV-B exposure, smoking, fair complexion, exposure to petroleum products, xeroderma pigmentosa, HIV, and human papillomavirus (HPV). These factors can also tip the scales for this condition to become more malignant in nature. Once diagnosed, treatment includes the use of chemotherapies such as mitomycin C, 5-fluorouracil, or interferon-a2b.The added benefits to using topical chemotherapeutics is that they can treat the entire ocular surface rather than the lesion itself and they are well-tolerated by patients.
Presentation
A 75-year-old Caucasian male presented with a growth on his right eye that he had noticed getting larger within the last year (Figure 1). The patient stated he was asymptomatic with no concerns of worsening vision or irritation/discomfort. Entering VA was 20/20 OD, OS with a gelatinous lesion encroaching the cornea temporally OD. Previously, the patient attempted instilling artificial tears with no improvement. Medical history included a diagnosis of diabetes mellitus Type 2, hypertension, and hypercholesterolemia. As well, he previously had a skin cancer lesion removed on his face (unspecified type). Concomitant medications included clopidogrel 75mg, atorvastatin 80mg, famotidine 40 mg, lisinopril 20mg, metoprolol 100mg, and glipizide 10 mg.
Figure 1. Baseline external photograph highlighting gelatinous lesion temporally along the conjunctiva.
Treatment
Originally, the patient was started on loteprednol 1 gtt QID OD for 2 weeks, then BID for 2 weeks. After no improvement was noted at the patient’s follow-up visit, an AS-OCT (Figure 2) was performed. This confirmed the appearance of OSSN. Based on the diagnosis, the management was switched to 5-fluorouracil (5-FU) 1% 1 gtt QID OD for 1 week on, then 3 weeks off. After 5 rounds, the patient had complete resolution of the gelatinous lesion (Figure 3) and was reminded frequently to continue UV protection.
Figure 2. AS-OCT provides further differentiation of the gelatinous lesion. Shown is a thickened area of hyperreflectivity, with an abrupt transition from normal to abnormal tissue.
Figure 3. Comparative external photo after multiple rounds of 5-FU. Lesion showed complete resolution following the treatment course.
Summary and Discussion
AS-OCT proves to provide a non-invasive method for detection of OSSN in the modern era. While surgical excision with cryotherapy is still accepted, one-third of patients will still exhibit reoccurrence due to an incomplete excision. Chemotherapeutics can provide a well-tolerated and effective first-line treatment. This case highlights the length of time patients may have to endure to see full resolution. In conjunction with patience, it is important to educate individuals on the importance of UV protection, cessation of smoking, and HIV/HPV risks to prevent the road to malignancy.
