Michael Thomas Corwin MD, Presenter: Nothing to Disclose

Adib Raphael Karam MD, Abstract Co-Author: Nothing to Disclose

Andrew John Smith MD, Abstract Co-Author: Nothing to Disclose

To determine the natural history of incidentally detected misty mesentery on computed tomography (CT) and correlate the development of malignancy with mesenteric LN size.

The study was approved by the institutional review board and informed consent was waived. A database search for the terms “misty,” “mesenteritis” and “panniculitis” in all CT examinations from 1/1/2004 to 12/31/2008 was performed. The CT images, reports, and clinical records were analyzed at the time of the original CT. Follow up was obtained by viewing all subsequent CT images, reports, and clinical records. Patients were excluded if the CT or clinical history revealed a potential etiology for the misty mesentery, the patient had a known history of malignancy, or no follow up CT for a minimum of 2 years. The largest mesenteric lymph node was measured in short axis on the original and all follow up CTs.

Forty four patients were included. The mean time interval between the original and latest follow up CT was 3.9 yrs (range 2.1 to 6.3). The mean initial lymph node size was 8 mm (range <5 to 35 mm). All 38 patients with largest mesenteric LN of 10 mm or less demonstrated stable LN size on all follow up CTs and none developed any malignancy. Three of the six (50%) pts with LN size >10 mm developed malignancy, all follicular lymphomas. The largest initial lymph node size in these patients was 17 mm, 17 mm, and 35 mm.

Incidentally detected misty mesentery demonstrates a benign course when the largest mesenteric lymph node is 10 mm or less. When the largest mesenteric lymph node is 10 mm or greater, there is a high risk of lymphoma.

Incidentally detected misty mesentery requires no follow up if the largest mesenteric lymph node is 10 mm or less, and further evaluation or follow up if it is greater than 10mm.

Corwin, M, Karam, A, Smith, A, Incidentally Detected Misty Mesentery on CT: Risk of Malignancy Correlates with Mesenteric Lymph Node Size.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11011485.html