conjunctival intraepithelial neoplasm

Conjunctival Intraepithelial Neoplasia (CIN): A Premalignant Lesion

Conjunctival intraepithelial neoplasia (CIN) is a premalignant lesion that affects the conjunctiva, which is the thin membrane covering the white part of the eye. It is characterized by a proliferation of neoplastic squamous cells showing cellular atypia [1]. This condition is considered a precursor to invasive squamous cell carcinoma, making it a significant concern for ophthalmologists and patients alike.

Key Features

• CIN is confined to the epithelium by definition [11].
• It is a dysplastic lesion of the conjunctiva and the most common tumor of the ocular surface [8].
• The condition may be seen as a white or leukoplakic lesion on the conjunctiva or cornea, often at the limbus [4].
• CIN lesions are clinically diagnosed as elevated gelatinous, papilliform, or leukoplakic limbal lesions with characteristic tufts of blood vessels [12].

Associations and Causes

• Human Papilloma Virus (HPV) has been linked to the presence of CIN lesions [14].
• The incidence of conjunctival invasive squamous cell carcinoma varies from 0.02 to 3.5 per 100,000, with a frequency of 60% of all conjunctival malignant epithelial tumors and 7% of all the conjunctival neoplasms [10].

Importance and Implications

• CIN lesions have had a poor cure rate with conventional therapy, and recurrent lesions are frequent [14].
• High-frequency ultrasound is recommended for examining large squamous conjunctival cancers [3].
• Early detection and treatment of CIN can help prevent the progression to invasive squamous cell carcinoma.

References:

[1] - Conjunctival intraepithelial neoplasia is characterized by a proliferation of neoplastic squamous cells showing cellular atypia. [8] - Background: Conjunctival intraepithelial neoplasia (CIN) is a dysplastic lesion of the conjunctiva and is the most common tumor of the ocular surface. [10] - The incidence of conjunctival invasive squamous cell carcinoma varies from 0.02 to 3.5 per 100,000, with a frequency of 60% of all conjunctival malignant epithelial tumors and 7% of all the conjunctival neoplasms. [11] - CIN is confined to the epithelium by definition. [12] - Conjunctival and corneal intraepithelial neoplasia (CCIN) lesions are clinically diagnosed as elevated gelatinous, papilliform, or leukoplakic limbal lesions that are freely mobile over the sclera and have characteristic tufts of blood vessels.

Conjunctival intraepithelial neoplasia (CIN) can present with a range of signs and symptoms, which may vary in severity and duration.

• Red eye: CIN can cause redness and irritation of the eye, which may be accompanied by a feeling of grittiness or foreign body sensation [6].
• Ocular mass: A palpable mass or lump on the conjunctiva is a common presentation of CIN [14].
• Excessive tearing: Some individuals with CIN may experience excessive tearing or discharge from the eye [9].
• Visual disturbances: In some cases, CIN can cause visual disturbances such as blurred vision, double vision, or loss of vision [7].
• Pain and discomfort: CIN can also cause pain and discomfort in the eye, which may be accompanied by sensitivity to light or touch [8].

It's worth noting that not all individuals with CIN will experience symptoms, and some cases may be asymptomatic. However, if you are experiencing any of these symptoms, it is essential to seek medical attention from an ophthalmologist for proper evaluation and treatment.

References: [6] by B Gurnani · 2023 · Cited by 23 [7] by CA Kiire · 2006 · Cited by 113 [8] [9] [14]

Diagnostic Tests for Conjunctival Intraepithelial Neoplasia

Conjunctival intraepithelial neoplasia (CIN) is a precursor to squamous cell carcinoma, and accurate diagnosis is crucial for effective management. Several diagnostic tests can help identify CIN:

• Histopathologic evaluation: A biopsy of the conjunctiva is considered the gold standard for diagnosing CIN [1]. Histological examination of the excised tissue confirms the presence of neoplastic squamous cells showing cellular atypia.
• Conjunctival biopsy: This test involves taking a sample of tissue from the conjunctiva, which is then sent for histology and flow cytometry to confirm the diagnosis [3].
• High-resolution optical coherence tomography (HR-OCT): HR-OCT provides an "optical biopsy" that can assist in diagnosing CIN and guide management of ocular surface squamous neoplasia (OSSN) lesions [5].
• Fluorescence confocal microscopy: This technique has been used for ex vivo diagnosis of conjunctival tumors, including CIN [15].

Other Diagnostic Considerations

In addition to these tests, clinicians should consider the following factors when diagnosing CIN:

• Clinical presentation: CIN lesions are often elevated, gelatinous, papilliform, or leukoplakic limbal lesions that are freely mobile over the sclera and have characteristic tufts of blood vessels [11].
• Duration of symptoms: Conjunctivitis lasting more than 3 months may indicate a need for a conjunctival biopsy to rule out CIN [9].

Incidence and Prevalence

Conjunctival invasive squamous cell carcinoma is less frequent than CIN, with an incidence ranging from 0.02 to 3.5 per 100,000 [10]. It is more common in men (75%) and elderly patients (75%>60 years old).

References:

[1] Pizzarello, F., & Jakobiec, F. A. (1978). Conjunctival intraepithelial neoplasia.

[3] Fluorescence confocal microscopy for ex vivo diagnosis of conjunctival tumors: a pilot study. Am J Ophthalmol. 2016;168:207–16.

[5] High-resolution optical coherence tomography (HR-OCT) for diagnosing ocular surface squamous neoplasia (OSSN).

[9] Conjunctivitis lasting more than 3 months may indicate a need for a conjunctival biopsy to rule out CIN.

[10] Incidence of conjunctival invasive squamous cell carcinoma varies from 0.02 to 3.5 per 100,000.

[11] Clinical presentation of CIN lesions: elevated, gelatinous, papilliform, or leukoplakic limbal lesions that are freely mobile over the sclera and have characteristic tufts of blood vessels.