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Mesenteric Inflammatory Venoocclusive Disease in a Patient with Sjögren's Syndrome

Mesenteric inflammatory venoocclusive disease is an uncommon cause of intestinal ischemia. Certain diseases, such as hypercoagulation disorders, autoimmune diseases, or drugs have been associated with the pathogenesis of mesenteric inflammatory venoocclusive disease. Here, we report a patient with Sjögren's syndrome who underwent surgery for suspected acute appendicitis with a subsequent pathological diagnosis of mesenteric inflammatory venoocclusive disease.


Introduction
Mesenteric inflammatory venoocclusive disease (MIVOD) is an uncommon cause of intestinal ischemia affecting the veins of the bowel and mesentery, which causes thrombotic occlusion of these veins. The etiology of MIVOD remains unclear because it is rarely suspected and often underreported.
Here we report a patient with Sjögren's syndrome (SS) who underwent surgery for suspected acute appendicitis with a subsequent pathological diagnosis of MIVOD. To our knowledge, this is the first case of MIVOD in a patient with SS, illustrating another possible gastrointestinal manifestation of this syndrome.

Case Report
A 60-year-old woman, smoker (20 cigarettes/day), with a history of SS, biliary cirrhosis, hypertension, hypercholesterolemia, and osteoporosis presented to the emergency department experiencing initial epigastric pain accompanied by progressive pain in the right lower quadrant, nausea, and fever over the last 12 days. At the time the patient was taking budesonide, ursodeoxycholic acid, enalapril, alendronate, and atorvastatin. She had undergone surgery for carpal tunnel syndrome and since then was taking NSAIDs.
On physical examination, she was normotensive and body temperature was 38 ∘ C. She was found to have lower right quadrant tenderness with peritoneal signs. Bowel sounds were normal.
Laboratory tests showed high C-reactive protein levels (1.80 mg/dL; n.v. < 0.05 mg/dL). White blood cell count and liver and pancreatic enzyme values were within normal ranges. The following results were obtained with autoantibody testing: positive anti-nuclear antibody was identified at a titer of 1 : 320 with a speckled pattern and the anti-Ro/SS-A Ab value was 717 U/mL (n.v. < 10 U/mL). Other autoantibodies, including anti-La/SS-B Ab, IgM rheumatoid factor, The initial clinical impression was that of acute appendicitis and a decision to operate was made. The laparotomy revealed mesenteric congestion of the right colon with widening of the terminal ileum. A normal appendix was removed and a mesocolon biopsy was undertaken.
Microscopic examination revealed marked edema and a perivenular lymphocytic infiltrate with some veins totally occluded. The arteries and arterioles were normal. These histopathological findings are consistent with the diagnosis of MIVOD (Figure 1).
The patient had no postoperative complications and recovered completely; no recurrence was observed during the followup period. Blood tests for hypercoagulability and systemic vasculitis were negative.

Discussion
Sjögren's syndrome (SS) is an autoimmune exocrinopathy involving mainly the parotid and lacrimal glands, although it can involve almost any other part of the gut. The degree to which SS affects the small and large bowel is unclear. Other symptoms include abdominal discomfort in 0%-37% of the cases, nausea in 0%-5%, constipation in 0%-23%, diarrhea in 0%-9%, and malabsorption in 0%-5%. However, documented intestinal involvement is rare to absent in large series [8].
A distinctive feature of MIVOD is the vasculitis of the mesenteric veins and their intramural tributaries. MIVOD seems to affect the colon in more than 50% of the patients, although it has also been reported to affect the small bowel, omentum, and gallbladder [17]. It is characterized by mesenteric venous inflammation and thrombosis, which results in chronic ischemia. No involvement of arterial inflammation or occlusion has been described.
Due to discrepancies in histological and imaging findings, these cases constitute a diagnostic challenge.
Inflammatory bowel disease, intestinal ischemia, and acute appendicitis are the major differential diagnosis. It is important to distinguish MIVOD from mesenteric venous thrombosis, as these patients may be put on anticoagulant therapy. Lymphocytic, necrotizing, and granulomatous patterns of inflammation in the mesenteric veins are characteristic features of MIVOD, not found in mesenteric venous thrombosis.
MIVOD is a pathological diagnosis; surgery is required for a definitive diagnosis and decide on the therapeutic procedure. Maintenance therapy is not necessary since the prognosis of MIVOD is excellent. Only one case of recurrent MIVOD has been reported [18]. Our patient recovered completely, and there has been no recurrence in 2 years of followup.