From the Guidelines
Mesenteric tumor deposits should be classified as pN1c in the absence of lymph node metastases, and their presence and number should be recorded in all cases, as they have adverse prognostic significance, as stated in the UICC/AJCC TNM 8th editions 1. When diagnosing mesenteric tumor deposits, it is essential to distinguish them from venous invasion, lymphatic invasion, or perineural invasion, as these have different implications for staging and treatment.
- The identification of a tumor deposit is considered under the node (N) rather than primary tumor (T) status for the purposes of staging, according to the UICC/AJCC TNM 8th editions 1.
- A mesenteric tumor without evidence of origin, which is discontinuous from the primary tumor and predominantly subserosal in location but penetrates the serosal surface of the mesentery, should be classified as a tumor deposit rather than as distant metastatic (pM1c) disease, as recommended by the international collaboration on cancer reporting (ICCR) 1.
- In cases where tumor regression follows neoadjuvant therapy, the distinction between discontinuous residual primary tumor foci and tumor deposits can be challenging, and the presence of intervening normal tissue is recommended to facilitate uniform interpretation, as suggested in the study published in the Annals of Surgery 1.
- The presence of tumor deposits in the presence of lymph node metastases should be recorded, as they have adverse prognostic significance, as evidenced by meta-analysis based on the UICC/AJCC TNM 7th editions definition 1.
From the Research
Definition and Characteristics of Mesenteric Panniculitis
- Mesenteric panniculitis is a rare, benign condition characterized by chronic inflammation and fibrosis of mesenteric adipose tissue 2, 3, 4.
- The condition is often asymptomatic, but when symptoms occur, they may include abdominal pain, nausea, weight loss, bloating, diarrhea, constipation, vomiting, anorexia, fever, malaise, and nausea 3, 5, 4.
Diagnosis of Mesenteric Panniculitis
- Diagnosis relies on a combination of imaging findings, particularly the characteristic "misty mesentery" appearance on CT scan, and when indicated, histological confirmation 2, 3, 4.
- Computed tomography (CT) is commonly used to detect mesenteric panniculitis, showing a mass-like area of increased fat attenuation within the small bowel mesentery 3, 5.
- Positron emission tomography/computed tomography (PET/CT) may be performed if there is suspicion of a concurrent underlying malignancy 3.
Treatment and Management of Mesenteric Panniculitis
- Treatment decisions should be guided by the severity of symptoms and the presence of complications 3, 4.
- First-line medical treatment includes prednisone and tamoxifen 3.
- Surgery is reserved for cases of recurrent bowel obstruction 3, 5, 6.
- Conservative treatment is often successful, and surgical intervention is not usually necessary 5, 4, 6.
Epidemiology and Etiology of Mesenteric Panniculitis
- The etiology of mesenteric panniculitis remains unclear, but it has been associated with various conditions, including abdominal surgery, trauma, and inflammatory diseases 2, 4.
- The condition can be influenced by many factors, mainly abdominal trauma and surgery 4.
- Underlying malignancy should be excluded, and careful monitoring is necessary to prevent complications 2, 3, 5.