Syphilitic Pulmonary Inflammatory Pseudotumor: A Diagnostic Challenge

Area of Science:

• Infectious Diseases
• Pulmonology
• Nephrology

Background:

• Secondary syphilis is a systemic infection with diverse clinical manifestations.
• Pulmonary involvement in secondary syphilis is rare and often misdiagnosed.
• Nephrotic syndrome can be an extrapulmonary manifestation of syphilis.

Observation:

• A 46-year-old man presented with cough, lower limb swelling, a lung mass, and subpleural nodules.
• Lung biopsy revealed inflammatory pseudotumor with lymphoplasmacytic infiltrate.
• Immunohistochemistry confirmed *Treponema pallidum* infection.

Findings:

• The patient had secondary syphilis presenting as a pulmonary mass and nephrotic syndrome.
• Treatment with benzathine penicillin led to complete resolution of both lung mass and nephrotic syndrome.
• Pulmonary inflammatory pseudotumor was the presenting manifestation of secondary syphilis.

Implications:

• This case underscores the importance of considering syphilis in the differential diagnosis of pulmonary masses.
• Early diagnosis and treatment of syphilitic lung disease can prevent serious complications.
• Syphilis should be investigated in patients with unexplained nephrotic syndrome and pulmonary findings.