Rectal syphilis mimicking histiocytic lymphoma

Area of Science:

• Infectious Diseases
• Oncology
• Gastroenterology

Background:

• Increasing recognition of homosexual activity necessitates awareness of associated health risks, including sexually transmitted infections.
• Physicians must be knowledgeable about the diverse clinical presentations of venereal infections within this population.
• Rectal masses can present diagnostic challenges, potentially mimicking other serious conditions.

Observation:

• A 23-year-old man presented with a rectal mass and diffuse adenopathy, initially diagnosed as histiocytic lymphoma via biopsy.
• The patient denied homosexual activity during initial evaluation.
• Subsequent serological testing revealed positive results for syphilis.

Findings:

• Further patient history revealed a history of anorectal intercourse.
• Special stains of the rectal mass confirmed the presence of spirochetes, identifying syphilis.
• The initial biopsy results were misleading, highlighting the importance of considering syphilis in differential diagnoses.

Implications:

• Syphilis should be considered in the differential diagnosis of rectal masses in young patients, irrespective of reported sexual history.
• The clinical presentation of syphilis can be atypical, mimicking malignancies like lymphoma.
• Accurate and timely diagnosis of syphilis is essential for appropriate treatment and patient outcomes.