Idelalisib: a rare cause of enterocolitis

Area of Science:

• Oncology
• Gastroenterology
• Pharmacology

Background:

• Idelalisib is an FDA-approved oral phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor for relapsed follicular B-cell non-Hodgkin lymphoma.
• Diarrhea is a frequent adverse effect of idelalisib treatment, observed in 47% of patients in clinical studies.

Observation:

• This case report details a female patient with recurrent follicular lymphoma who developed diarrhea during idelalisib treatment.
• The patient presented with entero-colitis, a significant gastrointestinal side effect linked to idelalisib therapy.

Findings:

• Characteristic histological findings of idelalisib colitis include intraepithelial lymphocytosis, neutrophilic cryptitis, and epithelial cell apoptosis.
• These specific histological features are crucial for differentiating idelalisib-induced colitis from other causes of diarrhea and entero-colitis.

Implications:

• Histological examination is vital for accurate diagnosis and management of idelalisib-related gastrointestinal toxicity.
• Successful treatment involved drug discontinuation and corticosteroid therapy (prednisone), highlighting a potential management strategy for idelalisib-induced colitis.