A Rare Cause of Enteritis in an Adult Male

ABSTRACT

Introduction: IgA vasculitis is more commonly seen in the pediatric population than in adults. Rarely IgA vasculitis is associated with malignancy, most commonly solid tumor malignancies, although there are case reports of association with hematologic malignancies. We report a case of large B-cell lymphoma mimicking IgA vasculitis in a 33-year-old immunosuppressed male with a prior history of IgA vasculitis. Case Description/Methods: A 33-year-old Caucasian male post renal transplant from reflux nephropathy on chronic immunosuppression was hospitalized for postprandial epigastric abdominal pain, nausea, vomiting and diarrhea. Two years prior, he was admitted for the same symptoms, palpable purpura of the lower extremities and elevated serum IgA. Enteroscopy had shown duodenal and jejunal ulceration with biopsies staining positive for IgA, confirming IgA vasculitis. He had complete resolution with a steroid taper. His current presentation had resulted in multiple hospital admissions, but empiric trial of steroids failed to alleviate symptoms. Vitals were normal and exam was notable for epigastric tenderness. Labs were notable for WBC 19.00 x103/cmm with normal differential, hemoglobin 9.2 gm/dL (prior 11.0 gm/dL), CRP 20.7 mg/L, serum creatinine 2.7 mg/dL (prior 1.5 mg/dL), and urinalysis with proteinuria, sterile pyuria, and hematuria. CTA abdomen/pelvis revealed thickening of the duodenum with shotty mesenteric lymph nodes without ischemia. Enteroscopy revealed an erythematous duodenum and jejunum (figure A). Jejunal biopsy (figure B) revealed CD20 positive cells consistent with DLCBL (figure C). He was seen by oncology and treated with R-CHOP but later unfortunately expired due to COVID-19 complications. Discussion(s) Non small cell lung cancer and renal cell carcinoma are most commonly associated with IgA vasculitis. It may also be seen in both Hodgkin and Non-Hodgkin lymphomas in adult patients. If IgA vasculitis occurs after a malignancy is diagnosed, it may indicate that metastasis has occurred. Malignancy associated IgA vasculitis is more likely to have an incomplete response to steroids and requires treatment of the underlying malignancy to achieve remission. Our case illustrates posterior probability error and premature closure cognitive biases. We should consider alternative diagnoses rather than anchor on prior diagnoses even when presentations are similar. Our case also highlights the importance of considering occult malignancy in adults with diagnosis of IgA vasculitis.