Atypical Presentation of a Rare Disease: Idiopathic Enterocolic Lymphocytic Phlebitis Mimicking Ulcerative Colitis

Abstract

Enterocolic lymphocytic phlebitis (ELP) is a rare cause of ischemic bowel injury. It is characterized by phlebitis of the bowel wall and mesenteric veins, without arterial involvement. The etiology and pathogenesis of this condition remains poorly understood. A 33-year-old Caucasian male, presented with intermittent abdominal pain, and blood in stools for six months. He was reportedly diagnosed with ulcerative colitis and was started on mesalamine. He denied sick contacts, recent travel, tobacco and alcohol use. His physical examination revealed left lower quadrant abdominal tenderness, without guarding or rigidity. Bright red blood and tenderness to palpation were noted on rectal examination. His initial laboratory studies were unremarkable, except for hemoglobin level of 12.6 g/dl, and an elevated C-reactive protein level of 3.3 mg/dl. CT scan of the abdomen showed normal bowel wall thickness. A comprehensive laboratory work-up was negative for Anti-Nuclear Antibody (Ab), Anti-myeloperoxidase Ab, Anti-proteinase 3 Ab, Anti-mitochondrial Ab, Anti-smooth muscle Ab, Saccharomyces cerevisiae IgA/IgG Ab, celiac serology, anti- CCP Ab and rheumatoid factor. Complement and immunoglobin levels were within normal range. Stool infectious panel and stool calprotectin levels were negative. Colonoscopy revealed, moderate to severe proctosigmoiditis from the anorectal junction. Histopathologic examination showed regenerative mucosal changes without evidence of cryptitis, crypt abscesses, or granulomas. He underwent laparoscopic low anterior resection with diverting ileostomy, after failing treatment with steroids, azathioprine and infliximab for three months. Surgical pathology showed discrete ulcers that extended into submucosa, and lymphocytic cuffing of small submucosal and mesenteric veins suggestive of ELP. Flexible sigmoidoscopy during one month follow up showed, diffuse areas of severely congested, eroded, friable, dusky, and necrotic appearing mucosa. He underwent total proctocolectomy with end ileostomy for recurrence of ELP involving the entire colon. He has been asymptomatic for one year post-proctocolectomy. Discussion: ELP commonly presents as acute abdomen with hematochezia. Histological features can range from granulomatous phlebitis, necrotizing phlebitis, to myointimal and endothelial hyperplasia. Endoscopic appearance may lead to misdiagnosis, as deep submucosal biopsies are needed to diagnose ELP. Surgical resection of the affected bowel is curative.