Anal canal plasmacytoma-An uncommon presentation site

Area of Science:

• Oncology
• Hematology
• Gastroenterology

Background:

• Extramedullary plasmacytomas (EMP) are rare plasma cell tumors originating outside the bone marrow.
• While commonly found in the head and neck, EMPs in the lower gastrointestinal tract, particularly the anal canal, are exceptionally uncommon.
• Anal canal EMP represents less than 5% of all EMP cases.

Purpose of the Study:

• To present an exceedingly rare case of anal canal plasmacytoma.
• To enhance understanding of this rare clinical entity.

Main Methods:

• A case report of a 61-year-old male with a 6 cm anal canal mass invading all layers.
• Biopsy revealed plasmacytoid cells expressing CD79a, CD138, and lambda chains, consistent with EMP.
• The patient received conformal radiotherapy (50.4 Gy total dose).

Main Results:

• The anal canal lesion completely disappeared after radiotherapy.
• The patient remained asymptomatic at 24-month follow-up.
• No evidence of disease in other locations was found.

Conclusions:

• Extramedullary plasmacytoma (EMP) constitutes approximately 3% of plasma cell malignancies, typically affecting males around 60 years old.
• Radiation therapy, around 50 Gy, is the primary treatment for EMP.
• Lifelong surveillance, including bone marrow aspiration and protein studies, is crucial for detecting potential multiple myeloma development.