SHM Converge Scientific Abstract ePoster Gallery-An Unusual Case of Pd-L1 Inhibitor Mediated Microscopic Colitis

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This case describes a 78-year-old woman with ovarian cancer, prior deep vein thrombosis, and recent treatment in the TESARO trial with dostarlimab and niraparib or placebo. She presented with three months of chronic non-bloody diarrhea, worsening fatigue, and lethargy. On arrival, she was profoundly hypotensive with a blood pressure of 69/38 mmHg, while the rest of her physical exam was unremarkable.<br /><br />Laboratory testing showed thrombocytosis and macrocytosis. A CT scan of the abdomen and pelvis suggested possible ileus, though small bowel obstruction could not be ruled out. Colonoscopy demonstrated diffuse increased mucosal vascular pattern throughout the colon and sigmoid diverticulosis. Biopsies from multiple colonic sites revealed chronic colitis with marked thickening and irregularity of the subepithelial collagen band, consistent with collagenous colitis.<br /><br />The diagnosis was immune-mediated colitis, likely related to checkpoint inhibitor therapy. She was treated with budesonide 9 mg daily for nine weeks for PD-L1 inhibitor–mediated microscopic colitis. The case highlights that immune-mediated colitis can present with prolonged diarrhea and significant hemodynamic compromise and may require colonoscopy with biopsy to confirm microscopic/collagenous colitis. Management depends on severity and often includes corticosteroids or steroid-like therapy.

Asset Subtitle

Silpa Yarra

Meta Tag

Author List Caileen Sennett, Carolina Villarroel, Ian Cohen, Silpa Yarra

Category Clinical Vignettes

Concept Immune-Mediated Colitis

Concept Immune Checkpoint Inhibitor Therapy

Concept Microscopic Colitis

Concept Chronic Diarrhea

Concept Colonoscopy

Distinguished Non-Finalist

Presenter Organization Mount Sinai Beth Israel Medical Center

Presenting Author Silpa Yarra

Track Adult

Keywords

ovarian cancer

dostarlimab

niraparib

immune-mediated colitis

collagenous colitis

chronic diarrhea

checkpoint inhibitor therapy

hypotension

colonoscopy biopsy

budesonide

Immune-Mediated Colitis

Immune Checkpoint Inhibitor Therapy

Microscopic Colitis

Chronic Diarrhea

Colonoscopy