S2893 A Common Malignant or a Rare Benign? Diagnostic Dilemma: A Case Report

Abstract

INTRODUCTION: Sclerosing mesenteritis (SM) is a rare benign disease of unknown etiology. About 15 % of patients are asymptomatic or have minimal symptoms. It is usually benign in its clinical course, however, SM can mimic certain malignant disorders, such as lymphoma. It poses a diagnostic challenge for clinicians as it can be mistaken for malignancy and vice versa. In our case, the patient diagnosis of lymphoma was obscured by the picture of sclerosing mesenteritis, especially with negative multiple lymph node biopsies. CASE DESCRIPTION/METHODS: A 31 years old Caucasian male with a medical history of PTSD and a history of intussusception of colon requiring large and small bowel resection at age 14 who presented with severe generalized abdominal pain. CT abdomen ruled out any acute abdominal process, though enlarged mesenteric and retroperitoneal lymph nodes worrisome for lymphoma were noted. No history of weight loss, night sweats, or B symptoms. Laboratory investigations demonstrate transaminitis, otherwise, they are relatively unremarkable. CT chest and neck were significant for cervical chain lymphadenopathy. EGD showed gastritis and colonoscopy showed sigmoid colitis. Given his prior laparotomy for intussusception, the patient had retroperitoneal LN biopsy by IR and the pathology was reactive lymph nodes. Excisional cervical LN biopsy revealed the same diagnosis. After an extensive diagnostic work-up including biopsy sampling, which was negative for malignancy, the symptoms and findings were thought to be related to sclerosing mesenteritis. A trial of steroids and tamoxifen did not improve the symptoms. The patient eventually had mesenteric LN resection and pathology revealed follicular lymphoma. DISCUSSION: Sclerosing mesenteritis is rare. In most cases, it is discovered incidentally on abdominal imaging for evaluation of nonspecific abdominal or systemic symptoms. Our case highlights an important clinical finding that lymphoma can masquerade as sclerosing mesenteritis. A presumptive diagnosis of SM can be based on abdominal CT findings of a halo sign or fat ring. However, a histologic evaluation is necessary to rule out other etiologies and confirm SM. Percutaneous biopsies might be non-diagnostic because fine-needle specimens often lack sufficient architectural representation to exclude malignancy. Excisional biopsy by laparoscopy or laparotomy is usually required to obtain tissue. Pathologic confirmation should be obtained in all cases of suspected sclerosing mesenteritis.