Primary Colonic Lymphoma With Paraneoplastic Hypercalcemia.

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Primary colonic lymphoma is an exceptionally rare malignancy, comprising a small fraction of all colorectal cancers.
• This report focuses on a unique case presentation of this rare condition.

Observation:

• A 63-year-old male presented with altered mental status secondary to hypercalcemia.
• Physical examination revealed a palpable abdominal mass on the right side.
• Imaging studies identified a colonic mass, subsequently diagnosed as diffuse large B-cell lymphoma via colonoscopy and biopsy.

Findings:

• The diagnosis of primary colonic lymphoma was established using the Dawson criteria, excluding extracolonic disease.
• Elevated calcitriol levels were identified, indicating a paraneoplastic manifestation of the lymphoma.

Implications:

• This case underscores the importance of considering rare gastrointestinal malignancies in the differential diagnosis of hypercalcemia.
• It highlights the potential for paraneoplastic syndromes to be the initial presenting feature of colonic lymphoma.
• Early recognition and diagnosis are crucial for effective management of primary colonic lymphoma.