[Anal metastasis from a lung cancer]

Area of Science:

• Oncology
• Gastroenterology
• Pathology

Background:

• Lung cancer is a leading cause of cancer-related mortality worldwide.
• Metastasis of lung cancer typically occurs in predictable patterns.
• Anal metastasis from lung cancer is an exceptionally rare event.

Observation:

• A patient presented with symptoms strongly suggestive of an acute anal abscess.
• Initial clinical presentation mimicked a common anorectal condition.

Findings:

• The anal mass was diagnosed as a metastasis from a primary lung cancer.
• Specific immunohistochemistry markers were crucial for identifying the origin of the metastatic cells.
• This case highlights an unusual site for lung cancer spread.

Implications:

• This case expands the differential diagnosis for anorectal masses.
• Awareness of rare metastatic patterns is essential for accurate and timely diagnosis.
• Immunohistochemistry plays a vital role in diagnosing metastatic disease of unknown primary origin.