Oral Syphilitic Lesion Mimicking Squamous Cell Carcinoma: A Case Report

Abstract

Background: Syphilis is a sexually transmitted infection that may manifest in the oral cavity, often mimicking malignant conditions such as oral squamous cell carcinoma (OSCC), particularly in patients with high-risk profiles for malignancy. Case Presentation: This report describes a 45-year-old female patient with a history of chronic smoking and alcohol consumption who presented with an ulcerated lesion on the lateral border of the tongue, clinically suggestive of OSCC. Despite the initial suspicion of malignancy, histopathological and immunohistochemical evaluations revealed a diagnosis of secondary syphilis. Findings: Microscopic analysis showed stratified parakeratinized epithelium with intraepithelial microabscesses and a dense perivascular lymphoplasmacytic infiltrate. Immunohistochemistry was strongly positive for Treponema pallidum, and serological testing (VDRL) confirmed active syphilitic infection. Conclusion: This case underscores the need to consider infectious diseases in the differential diagnosis of suspicious oral lesions. A comprehensive diagnostic approach—including serology, histopathology, and immunohistochemistry—is essential to avoid misdiagnosis and to guide appropriate management.