[A case of idiopathic myointimal hyperplasia of mesenteric veins]. / Un cas d'hyperplasie myointimale idiopathique des veines mésentériques du côlon.

The idiopathic myointimal hyperplasia of mesenteric veins is a rare pathology, affecting recto-sigmoid and mimicking clinically an inflammatory chronic disease of the bowel. Only about fifteen cases have been reported in the literature. This lesion is characterized by a myointimal thickening of the mesenteric veins, without inflammatory infiltrate of the vascular wall, differentiating it from vasculitis. We present here the case of a 48-year-old man, in whom the diagnosis of ulcerative colitis then digestive vasculitis had first been raised.

Idiopathic myointimal hyperplasia of mesenteric veins: Rare case of ischemic colitis mimicking inflammatory bowel disease.

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood ischemic colitis that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. A 76-year-old Japanese man presented to our hospital with a 1-year history of worsening diarrhea, lower abdominal pain, and weight loss (-6 kg). Laboratory evaluation revealed white blood cell count of 13,200/µL, C-reactive protein level of 2.0 mg/dL (normal range, 0.0-0.3), and negative results for stool culture (including Clostridium difficile). Colonoscopy showed circumferential and edematous narrowing of the sigmoid colon with deep longitude ulceration. Biopsy was done and examination of the specimen demonstrated no specific ischemia. The patient was treated with bowel rest, antibiotics, and i.v. fluids; however, his symptoms worsened. Finally, sigmoidectomy was carried out. Histological examination demonstrated significant myointimal hyperplasia of mesenteric veins leading to thickening and stenosis of the venous lumen. Therefore, the final diagnosis was IMHMV. Three months following sigmoidectomy, he was asymptomatic.

CT findings in idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) and comparison to other colitides.

PURPOSE: The purpose of this study is to determine computed tomography (CT) findings that aid in differentiating idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) from other colitides. METHODS: Retrospective review of histiologic proven cases of IMHMV (n = 12) with contrast enhanced CT (n = 11) and/or computed tomography angiography (CTA) (n = 9) exams. Control groups comprised of CT of infectious colitis (n = 13), CT of inflammatory bowel disease (IBD) (n = 12), and CTA of other colitides (n = 13). CT exams reviewed by 2 blinded gastrointestinal radiologists for maximum bowel wall thickness, enhancement pattern, decreased bowel wall enhancement, submucosal attenuation value, presence and location of IMV occlusion, peripheral mesenteric venous occlusion, dilated pericolonic veins, subjective IMA dilation, maximum IMA diameter, maximum peripheral IMA branch diameter, ascites, and mesenteric edema. Presence of early filling veins was an additional finding evaluated on CTA exams. RESULTS: Statistically significant CT findings of IMHMV compared to control groups included greater maximum bowel wall thickness, decreased bowel enhancement, IMV occlusion, and peripheral mesenteric venous occlusion (p < 0.05). Dilated pericolonic veins were seen more frequently in IMHMV compared to the infectious colitis group (64% versus 15%, p = 0.02). Additional statistically significant finding on CTA included early filling veins in IMHMV compared to the CTA control group (100% versus 46%, p = 0.008). CONCLUSION: IMHMV is a rare chronic non-thrombotic ischemia predominantly involving the rectosigmoid colon. CT features that may aid in differentiating IMHMV from other causes of left-sided colitis include marked bowel wall thickening with decreased enhancement, IMV and peripheral mesenteric venous occlusion or tapering, and early filling of dilated veins on CTA.

Idiopathic myointimal hyperplasia of mesenteric veins: radiological evaluation using CT angiography.

A 44-year-old man presented with a chief complaint of constipation. Initial contrast-enhanced CT showed extensive bowel wall thickening, mainly in the left colon, with a thin cord-like inferior mesenteric vein (IMV), in contrast to ectatic mesenteric venous branches, suggesting bowel ischaemia owing to venous stasis. One month later, at the time of symptom exacerbation, CT angiography showed a cord-like IMV and ectatic mesenteric venous branches with early enhancement, suggesting the presence of an arteriovenous fistula (AVF). Owing to the progression of bowel ischaemia and necrosis with peritonitis, emergency surgery was performed. Surgical specimens showed focal myointimal hyperplasia of the proximal mesenteric veins in both ischaemic and non-ischaemic lesions of the resected colon, thus leading to the diagnosis of idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) when combined with the clinical and imaging findings. IMHMV is a bowel ischaemic disease caused by non-thrombotic venous obstruction that requires bowel resection and has been suggested to be associated with AVF. Cord-like IMV and AVF in the mesentery are important CT findings that characterize IMHMV. CT angiography is useful in diagnosing IMHMV.

Atypical presentation of a rare disorder; idiopathic myointimal hyperplasia of mesenteric veins (IMHMV): Report of two cases.

INTRODUCTION: Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare type of chronic colonic ischemia. Patients commonly present with progressive abdominal pain, bloody diarrhea, and weight loss. IMHMV is a common mimicker of inflammatory bowel disease. However, medical management does not have a primary role and curative treatment is surgical resection. PRESENTATION OF CASE: We report two cases of IMHMV with atypical presentation. The first is an 82-year-old male who had refractory, painless, explosive, and non-bloody diarrhea initially treated with antidiarrheal medications and dietary changes to no effect. Colonoscopy was not clarifying. However, CT scan had characteristic findings of IMHMV. He underwent partial colectomy and recovered well. The second case is a 59-year-old male who had recurrent episodes of sudden, massive diarrhea. He was initially treated for diverticulitis based on colonoscopy findings but did not experience relief. Eventually, MRI of the abdomen was suggestive of IMHMV. He underwent surgical resection, which confirmed the diagnosis of IMHMV. He was treated for Clostridioides difficile diarrhea five months after surgery and pulmonary embolism seven months after surgery. With over a year of follow up, neither has had disease recurrence. DISCUSSION: Diagnosis and treatment of rare disorders like IMHMV is challenging, especially when they mimic common entities or present in atypical ways. CONCLUSION: We present two cases to highlight IMHMV as part of the differential for colitis-like symptoms. These cases demonstrate the importance of diagnostic imaging in diagnosis. Diagnostic uncertainty can lead to exposure to ineffective medical treatments and delay in curative surgery.

Idiopathic myointimal hyperplasia of mesenteric veins depicted by barium enema examination, and conventional and magnifying colonoscopy.

A 71-year-old man was admitted to our institution complaining of abdominal pain and constipation. Barium enema examination revealed narrowing, cobble stoning, and longitudinal ulcerations in the sigmoid colon and upper rectum. Conventional colonoscopy, magnifying narrow-band imaging endoscopy, and magnifying chromoendoscopy revealed edematous mucosa, longitudinal ulcerations with luminal narrowing, and multiple pseudopolyps. The histologic examination of the biopsy specimens showed thick-walled (arterialized) capillaries and subendothelial fibrin deposits in the mucosa and submucosa. Based on a preoperative diagnosis of idiopathic myointimal hyperplasia of mesenteric veins (IMHMV), he underwent a laparoscopic resection of the sigmoid colon and upper rectum. The histologic examination of the resected specimens showed marked proliferation of venous walls with marked myointimal thickening and luminal occlusion from the submucosa to the mesentery throughout the entire resected tissue section. The final diagnosis was IMHMV.

Smooth muscle degeneration of the mesenteric and branching veins causing ischemic enteritis: a case report.

BACKGROUND: Ischemic bowel injuries are generally caused by arteriosclerosis, thromboembolism, or vasculitis. Ischemic enteritis is less common than ischemic colitis because of the rich collateral arteries of the small intestine. In the present case, smooth muscle degeneration of the mesenteric to the submucosal veins caused ischemic enteritis and small bowel obstruction. CASE PRESENTATION: An 85-year-old woman with recurrent enteritis eventually developed small bowel obstruction. We performed laparoscopic partial resection of the small intestine. The pathological findings revealed smooth muscle degeneration of the mesenteric veins that caused ischemic enteritis. Venous changes were detected not only in the injured region, but also in a part of the normal region of the resected specimen. She continued to experience some minor symptoms postoperatively; however, these symptoms subsided in a short period with medicine discontinuation. CONCLUSION: This report shows the possibility that a disease causes ischemic enteritis with unique venous pathological changes and may recur postoperatively.

Idiopathic Myointimal Hyperplasia of Mesenteric Veins (IMHMV) with two spontaneous bowel perforations: A case report and literature review.

INTRODUCTION AND IMPORTANCE: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a poorly understood disorder which poses a diagnostic challenge to clinicians and pathologists. Here we have described the case of a male patient with IMHMV along with a presumed history of ulcerative colitis for 1 year. CASE PRESENTATION: A 55-year-old male presented to the OPD with history of chronic abdominal pain. Clinical and radiological examination coupled with endoscopic findings resulted in the patient being wrongly diagnosed to be a case of ulcerative colitis and was managed accordingly. Throughout his multiple hospital visits following treatment for ulcerative colitis, the patient was persistently symptomatic. He presented with 10 days history of increasing abdominal pain and constipation following which he developed spontaneous colonic perforation for which he underwent exploratory laparotomy left colectomy and Hartman's procedure. The final pathology of the resected colon found to be consistent of Idiopathic myointimal hyperplasia of the mesenteric veins and ischemic bowel changes. CLINICAL DISCUSSION: The absence of clear-cut endoscopic biopsy findings of ulcerative colitis made radiological picture to be the mainstay for diagnosis, which was inaccurate and exposed the patient to unnecessary treatment with immuno-modulators thus resulting in poor response to treatment. As the disease progressed, further narrowing of the vessels made the clinical picture to look closer to ischemic bowel pathology as the patient developed a top surgical emergency (i.e. bowel perforation). Such pathological finding (IMHMV) can only be diagnosed in a fully prepared tissue histology, but rather be considered when no other consistent alternative diagnosis was found. CONCLUSION: The treating physicians must definitely consider the possibility of idiopathic myointimal hyperplasia of mesenteric veins when similar manifestations are encountered in biopsy specimens of old cases with suspected inflammatory bowel disease or non-occlusive ischemia of the distal colorectum.

A case of idiopathic myointimal hyperplasia of the mesenteric veins presenting with small bowel obstruction.

BACKGROUND: Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is a rare ischemic bowel disease with venous occlusion resulting from the proliferation of smooth muscles in the venous intima. In most patients, the disease affects rectosigmoid colon and causes persistent abdominal pain and hematochezia, which is similar to inflammatory bowel disease (IBD). In addition, it is difficult to make a precise diagnosis of IMHMV without surgery. CASE PRESENTATION: An 81-year-old woman was admitted to our hospital with mild abdominal pain, nausea and vomiting. Repeated adhesive ileus was suspected due to the previous open and laparoscopic surgeries. Surgery was planned to treat small bowel obstruction. Intraoperatively no adhesive lesions were observed. However, a mass lesion was seen at the terminal ileum, which was suspected to have caused her bowel obstruction. Partial resection of the small intestine was performed. Macroscopic and histopathological examinations of the excised specimen showed circumferential ulceration with scarring, a thickened venous wall with active inflammation, and fibrotic changes that consequently produced stenosis and obstruction of the venous lumen in the subserosa. Additionally, Elastica van Gieson staining demonstrated thickening of the venous intima. The final diagnosis was IMHMV. At two years and 8 months after the operation, the patient was well without any additional medication. CONCLUSION: IMHMV of the small intestine is rare. We described a case of IMHMV that was associated with ileus.

Idiopathic myointimal hyperplasia of the mesenteric veins: Case report and review of the literature.

In 1991, Genta and Haggitt described four patients with segmental ischemic colitis caused by idiopathic myointimal hyperplasia in the small mesenteric veins (IMHMV). There are now 33 published cases of IMHMV in the literature; however, this condition is still sufficiently rare that it poses a diagnostic challenge to pathologists and clinicians and is often clinically or histologically confused with inflammatory bowel disease (IBD) or ischemic colitis. IMHMV is characterized by intimal smooth muscle hyperplasia resulting in thickened small and medium-sized mesenteric veins (with arterial sparing). Clinically, it presents with symptoms that mimic IBD, such as bloody diarrhea, abdominal pain, and weight loss. Surgical resection appears to be curative. The present case describes a 63-year-old Vietnamese man with cardiovascular risk factors who was diagnosed with IMHMV after many months of severe symptoms. A review of the current literature follows the case report.

The radiologic diagnosis of idiopathic myointimal hyperplasia of mesenteric veins with a novel presentation: case report and literature review.

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare condition of the rectosigmoid colon that primarily affects middle-aged men. IMHMV typically presents as proctosigmoiditis and often requires surgical resection due to complications throughout the protracted clinical course. It can be differentiated from idiopathic chronic inflammatory bowel disease by histopathologic examination of surgically resected colon specimens. This report describes a rare case of IMHMV presenting as left hemicolitis in a 64-year-old male. We also describe potentially distinguishing computed tomographic and angiographic findings that may aid in the diagnosis of IMHMV.