Mesenteric fibromas are rare intra-abdominal spindle cell tumors. Ex?perience with cases involving operative intervention in pregnant patients is limited. The authors report a case in?volving sinistral hypertension in a gra?vid patient with a mesenteric fibroma occluding the splenic vein. Opera?tive intervention is discussed and a literature review comparing this ex?per?ience with previous cases of mesenteric fibromatosis is provided.
Although mesenteric fibromas are the most common primary tu?mors of the mesentery, they are still relatively rare.1-6 These tumors share many of the pathologic features of gastrointestinal stromal tumors (GISTs), thus the two can be confused. Mesenteric fibromas usually cause intestinal obstruction.5 We describe the case of a pregnant patient with an abdominal mass that occluded her splenic vein, leading to sin?istral hypertension and hematemesis.
A 24-year-old, gravida 2, para 1, wom?an presented to an outside facility be?cause of an episode of acute upper gastrointestinal hemorrhage. She was 30 weeks pregnant and had been experiencing some mild weakness since week 28 of her pregnancy. Upon arrival to the outside facility, her hemoglobin was 8.3 g/dL and her serum amylase and lipase levels were within normal limits. An esophagogastroduodenoscopy was performed, which re?vealed gastric varices. Spiral computed tomography (CT) scanning showed what appeared to be a large cystic mass, which was suspected of compressing the splenic vein (Figure 1). The patient had no medical history of alcoholism, pancreatitis, hyperlipidemia, or liver disease. She had no recent symptoms of abdominal pain or jaundice, and her abdominal examination was benign. Due to the complexity of her case, she was transferred to our regional referral center.
The patient arrived at our institution hemodynamically stable but with continued coffee-ground emesis and melena. Her hemoglobin on arrival was 8.6 g/dL. She was started on a continuous somatostatin infusion. Since she continued to experience upper gastrointestinal hemorrhage despite maximal medical therapy, the decision was made to proceed with a splenectomy and distal pancreatectomy. The patient was vaccinated appropriately as prophylaxis for her upcoming splenectomy. In addition, the obstetricians ex-amined her and agreed with the plan to proceed with the operation but re?quired that she undergo continuous intraoperative tocometry. The patient received terbutaline and beta?methasone prior to surgery.
A high upper transverse incision was used because of the gravid uterus. The lesser sac was entered, and the distal pancreas and spleen were fully mobilized. Dis?section proceeded in a medial to lateral manner after division of the tail of the pancreas with a GIA? stapler. The cystic mass adhered to the superior aspect of the fourth portion of the duodenum (Figure 2). It was removed en bloc along with the tail of the pancreas and the spleen. The main pancreatic duct was oversewn in two layers using figure of eight, 4-0 Proline? sutures in the duct and interrupted, overlapping, horizontal mattress sutures through the pancreatic paren?chyma. The patient and fetus tolerated the operation well. Pathology was consistent with a mesenteric fibroma with cystic degeneration (Figure 3). S100 and CD34 stains were negative. The pa?tient had an un?eventful recovery and was discharged to home on postoperative day 9. She received a total of 16 units of blood and 4 units of fresh frozen plasma throughout the course of her presentation and treatment.
Intra-abdominal spindle cell tumors include desmoids, GISTs, and mesenteric fibromas. Mesenteric fibromas are the most common primary tumors of the mesentery, and they are often multiple. Although most cases of mesenteric fibromas are sporadic, they are associated with certain conditions such as familial adenomatous polyposis, Gardner's syndrome, and previous abdominal sur?gery.2,5,7 These masses are also associated with high levels of circulating estrogen.8
From a histologic standpoint, mesenteric fibromas appear macroscopically as white tumors with a whorled cut surface.9 Figure 3 illustrates the typical histologic characteristics of these tumors. Mesen?teric fibromas exhibit spindle cells typical of desmoids and GISTs. Unlike GISTs, these tumors do not exhibit necrosis, hemorrhage, or many mitoses.10 They also do not stain positive for CD34 and S100, which further differentiates them from GISTs.
Management of mesenteric fibromas usually involves surgery for symptomatic lesions. Surgical therapy is directed toward complete resection with en bloc extirpation of involved organs whenever possible. With complete resection, recurrence is low except in patients with Gardner's syndrome, who exhibit a higher incidence of local recurrence. There has been limited experience with the medical management of mesenteric fibromas; however, there has been moderate success using selective estrogen receptor modulators in the medical management of these lesions.11 Mesenteric fibromatosis, the dif?fuse form of this disease, may be treated medically.
While frequently utilized, the benefit of somatostatin and somatostatin analogues in gastric and esophageal varices has not been thoroughly investigated and present data are inconclusive.12 Although not extensively studied in gravid women, somatostatin remains a pregnancy category B drug and can be used safely for limited periods of time in this setting. Its mechanism of action can be related to the reduction of splanchnic blood flow with the subsequent reduction of portal pressure. Use of such preparations to stop acute bleeding may be useful to maintain some degree of hemostasis. Somatostatin was used in our patient to allow her to be safely transferred to a tertiary facility for continued care.
Sinistral hypertension, or left-sided por??tal hypertension, results from de?creased or absent flow through the splenic vein, leading to splenic decompression via alternative routes. The short gastric veins often take on the additional flow, resulting in engorgement and gastric varices. Splenic vein occlusion has many causes including pancreatic masses and chronic pancreatitis. Treatment options include expectant management or splenectomy. Advo?cates of splenectomy cite the negligible rate of re-bleeding after operative removal of the spleen. Advocates of expectant management justify this treatment strategy only for asymptomatic patients.13,14
This is the first reported case of upper gastrointestinal hemorrhage as a result of splenic vein thrombosis attributed to a mesenteric fibroma. Due to our patient's continued need for blood transfusions, she was not a candidate for expectant management. Open splenectomy and distal pancreatectomy were the operations of choice based on the location of the mass. The patient's enlarged uterus prohibited a laparoscopic approach.
Mesenteric fibromas are the most common primary tumors of the mesentery, but are still relatively rare. Man?agement for symptomatic lesions is operative resection. Sinistral hypertension in symptomatic patients is best treated with splenectomy.
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