Primary Acquired Melanosis: Clinical, Histopathologic and Optical Coherence Tomographic Correlation

Area of Science:

• Ophthalmology
• Medical Imaging
• Histopathology

Background:

• Primary acquired melanosis (PAM) is a potentially vision-impairing condition affecting the conjunctiva and cornea.
• Accurate diagnosis of PAM is crucial for appropriate management and to rule out malignancy.
• Anterior segment optical coherence tomography (OCT) offers non-invasive imaging capabilities.

Purpose of the Study:

• To evaluate anterior segment OCT as an adjunct diagnostic tool for primary acquired melanosis (PAM).
• To correlate clinical, histopathologic, and anterior segment OCT findings in PAM patients.
• To assess the utility of OCT in identifying features suggestive of malignant potential in PAM.

Main Methods:

• Twenty-four patients diagnosed with conjunctival or corneal PAM underwent anterior segment OCT imaging.
• Histopathologic analysis was performed on biopsies from 13 of the 24 patients.
• OCT findings were analyzed for characteristic features and correlated with histopathology.

Main Results:

• Histopathologic confirmation of PAM was achieved in 54.6% of cases.
• Anterior segment OCT demonstrated a consistent 20 μm thick basal epithelial hyperreflective band in 100% of patients.
• This hyperreflective band on OCT correlated with basal epithelial melanocytic pigmentation on histopathology.

Conclusions:

• Anterior segment OCT shows a characteristic finding (basal epithelial hyperreflective band) in PAM.
• OCT can serve as a non-invasive tool to support clinical and histopathologic diagnosis of PAM.
• Enhanced OCT resolution is needed to detect melanocytic hyperplasia and atypia, crucial for assessing malignant risk.