Co-occurring noncaseating granulomas and neurological manifestations as key indicators of secondary syphilis: a case and brief literature review

Introduction Granulomatous secondary syphilis is an uncommon and atypical presentation of Treponema pallidum infection, usually characterized by nonindurated rashes rather than granulomas. This variant often presents with persistent red-brown papules, nodules, or plaques on the trunk and extremities, including the palms and soles – a feature that helps differentiate it from typical secondary syphilis. We report a case of a 61-year-old woman who exhibited unexplained anemia, severe headaches, muscle weakness, blurred vision in her right eye, and multiple, firm, painless, disseminated erythematous papules on her skin and at the mucocutaneous junction of the right eye, all occurring without prior trauma. A comprehensive evaluation confirmed secondary syphilis with multiple noncaseating granulomatous lesions in the bone marrow and skin, along with neurosyphilis. The patient was initially treated with doxycycline due to a documented penicillin allergy. Her sexual partner was also tested and treated to prevent reinfection. Following treatment, she showed significant clinical, hematological, and serological improvements. We believe this is a unique case demonstrating disseminated noncaseating granulomatous involvement of the bone marrow and skin in secondary syphilis, which is frequently misdiagnosed and may indicate untreated, severe, or immunocompromised disease. An exhaustive approach – including thorough clinical assessment and vigilant follow-up – is critical for effective management, particularly after excluding other malignant or reactive granulomatous conditions.