Conjunctival lichen planus simulating ocular surface squamous neoplasia.

Purpose: To describe the history and clinical presentation of a case of conjunctival lichen planus simulating ocular surface squamous neoplasia (OSSN).

Methods: A 32-year-old Hispanic man presented with a 6-month history of worsening foreign body sensation, localized conjunctival hyperemia, and a progressively enlarging "bump" located in the temporal aspect of his right eye. The patient denied any prior ocular trauma or surgery to the affected eye. Evaluation consisted of slit lamp examination and surgical excision of the mass with histopathologic studies.

Results: Slit lamp examination revealed the presence of a 6 x 5 x 1 mm elevated conjunctival fleshy mass that extended into the corneal limbus in the right eye. The lesion exhibited intrinsic pigmentation and vascularization as well as the presence of a dilated feeder vessel. Based on clinical findings, a diagnosis of OSSN was suspected. An excisional biopsy was performed with cryotherapy application to the surgical margins. Histopathologic study of the lesion revealed hyperkeratosis, parakeratosis, irregular acanthosis, and a band-like infiltrate of predominantly lymphocytes hugging the epithelium, consistent with the diagnosis of lichen planus.

Conclusion: Ocular lichen can present as a focal conjunctival lesion. Excisional biopsy allowed us to make the diagnosis of this rare entity, which presented as a simulating lesion with clinical features consistent with ocular surface squamous neoplasia.