Successful treatment of sclerosing mesenteritis with tamoxifen monotherapy

Abstract

Sclerosing mesenteritis is a rare disorder characterized by fat necrosis, chronic inflammation, and fibrosis of the small bowel mesentery. With a paucity of published clinical trials on sclerosing mesenteritis, treatment is based on case reports and trials of other fibrosing diseases, such as idiopathic retroperitoneal fibrosis. We present a case of a 68-year-old woman with sclerosing mesenteritis who exhibited complete symptomatic and radiographic resolution with the use of tamoxifen monotherapy.

Sclerosing mesenteritis is a rare idiopathic disorder of fat necrosis, inflammation, and fibrosis of the mesentery. The etiology of the condition remains largely speculative; however, case reports attribute etiology most commonly to prior abdominal trauma or surgery, followed by malignancy and autoimmune conditions.¹ While the disease is often asymptomatic, a subset of patients develop complications from the mass effect on gastrointestinal, mesenteric, vascular, or lymphatic structures.² A small percentage of patients may develop further complications such as small bowel obstruction, chylous ascites, or superior mesenteric vein thrombosis.² The differential diagnosis is broad and includes any cause of mesenteric edema, hemorrhage, or infiltration with inflammatory or neoplastic cells.³

Given the rarity of the disease, treatment of idiopathic sclerosing mesenteritis is based on case studies, along with clinical trials of idiopathic retroperitoneal fibrosis. While glucocorticoids and immunosuppressive therapies remain the preferred primary treatment for retroperitoneal fibrosis, tamoxifen has also been described as a treatment option, with the first case report published in 1991.⁴ Since then, several other reports have confirmed the efficacy of tamoxifen, specifically in patients who cannot tolerate long-term, high-dose glucocorticoids.^5–7 A comparative study of glucocorticoids and tamoxifen monotherapy in a large group of patients confirmed that tamoxifen is a suitable therapeutic alternative with a low recurrence rate.⁸ The first case of tamoxifen monotherapy used to treat sclerosing mesenteritis was described in 1997, but there have been few reports since then.⁹ In this paper, we report one such patient with a mesenteric mass found to be sclerosing mesenteritis who exhibited complete symptomatic and radiographic resolution with the use of tamoxifen monotherapy.

CASE DESCRIPTION

A 68-year-old woman presented to an outside hospital in 2008 with 3 weeks of intermittent abdominal pain, diarrhea, and nausea. Her past medical history included type 2 diabetes, diabetic retinopathy, and coronary artery disease. Her past surgical history included hiatal hernia repair, hysterectomy, bilateral oophorectomy, bilateral cataract surgery, and coronary artery stent. A computed tomography (CT) scan obtained after presentation noted a 10 cm mesenteric mass (Figure 1a). The patient underwent abdominal exploration, where a 10 × 15 cm mass was found to be encompassing the mesentery and the mesenteric vessels. No seeding was noted in the peritoneal cavity. While the initial intent of the exploration was resection, the mass was found to be unresectable. Excisional biopsies, therefore, were performed. A frozen section biopsy of the mass was reported as retroperitoneal fibrosis. No malignant cells were seen. Another biopsy was taken for permanent section, with slides sent to the Mayo Clinic. Pathology results were reported as fat necrosis, fibrosis, and mixed chronic inflammatory cell infiltrate, consistent with sclerosing mesenteritis. A stain for estrogen receptors was negative.

Figure 1.

Axial CT of the abdomen (a) initially revealing an ill-defined 10 × 5 cm soft tissue mass extending from the mesentery to encase the small bowel in the left lower abdominal quadrant, containing scattered, coarse internal calcifications with surrounding “misty” soft-tissue attenuation; and (b) after 3 months of tamoxifen therapy, demonstrating complete resolution of the soft tissue mass in the left lower abdominal quadrant.

The patient was then referred to the senior author and started on a trial of tamoxifen 20 mg daily. She was evaluated 3 months after starting tamoxifen. When a CT scan was compared with the initial CT scan obtained 5 months earlier, there was complete resolution of the mass with no residual mesenteric stranding (Figure 1b). Her symptoms improved. Physical examination showed a healed incision with no palpable masses. It was recommended that the patient continue tamoxifen with evaluation by CT if recurrent symptoms developed. No additional imaging was obtained since the patient remained asymptomatic.

DISCUSSION

Sclerosing mesenteritis refers to the disease spectrum consisting of mesenteric lipodystrophy, mesenteric panniculitis, and retractile mesenteritis and thus has become an umbrella term for benign fibroinflammatory disease of the mesentery.² While the underlying pathophysiology remains unknown, histopathologic studies suggest that the disease progresses in stages from early fat necrosis, to chronic inflammation, and ultimately fibrosis.¹⁰ The clinical signs and symptoms of sclerosing mesenteritis are nonspecific, as patients can be asymptomatic or present with nonspecific abdominal pain, changes in bowel habits, weight loss, or nausea and vomiting. An abdominal mass may be palpable in a third of patients, with 20% to 30% having nonspecific abdominal tenderness on palpation. Diagnosis is typically made with CT, often with the finding of “misty mesentery,” a term used to describe increased mesenteric fat density.¹¹

Given the lack of therapeutic trials, treatment recommendations are based on case reports, small case series, and trials in other fibrosing diseases such as idiopathic retroperitoneal fibrosis.² Tamoxifen has been described as a treatment option for retroperitoneal fibrosis, specifically for patients who cannot tolerate high-dose glucocorticoids.⁷ The mechanism by which tamoxifen exerts its effect is unknown but is thought to be hormonal independent. It has been suggested that tamoxifen affects growth factors that inhibit fibroblast proliferation, which may explain its role in the treatment of both retroperitoneal fibrosis and sclerosing mesenteritis. Its antiangiogenic and antiestrogen properties may also contribute to its efficacy, perhaps suppressing inflammation and immune-mediated responses.⁷

Given the potential for side effects, treatment of sclerosing mesenteritis is recommended only in patients with significant symptoms that affect quality of life.² Current recommendations for medical treatment include tamoxifen plus corticosteroid as first-line therapy. The largest case series of 92 patients reported the best outcomes in patients who received a corticosteroid taper plus tamoxifen.¹ The use of tamoxifen alone is limited to case reports, such as the one presented here, and is an option in those with contraindications to corticosteroids.¹² Based on experience in retroperitoneal fibrosis, tamoxifen is recommended indefinitely to prevent relapse.¹³ Prior to initiation of treatment, patients should be counseled about potential side effects of tamoxifen, including hot flashes, venous thromboembolism, stroke, and endometrial carcinoma.¹⁴

This case describes a patient with complete symptomatic and radiographic response of sclerosing mesenteritis to tamoxifen monotherapy despite being estrogen receptor negative. The current recommendation for monitoring in the absence of clinical deterioration is following patients clinically. From 2008 through publication date, our patient has had no further clinically significant symptoms related to her sclerosing mesenteritis.

Disclosure statement/Funding

The authors report no funding or conflicts of interest. Permission for publication of this case was granted by the patient’s representative.