Acute fulminant necrotizing mesenteric lymphadenitis causing bowel ischemia

 

Executive Summary

This briefing details a rare and critical case of acute fulminant necrotizing mesenteric lymphadenitis in a 56-year-old male. While mesenteric lymphadenitis is typically a self-limiting inflammatory condition in pediatric populations, this case demonstrates a severe, life-threatening progression in an adult, resulting in mesenteric fat necrosis, vascular thrombosis, and subsequent small intestinal ischemia and obstruction.

Despite an exhaustive diagnostic workup—including cultures for bacterial, viral, fungal, and tuberculous agents, as well as extensive autoimmune screening—the primary etiology remains unidentified. The patient was successfully managed through emergent surgical resection of the necrotic nodes and ischemic jejunum, followed by a duodenal-to-distal-jejunal anastomosis. This case highlights the necessity of considering necrotizing lymphadenitis in adult patients presenting with acute small bowel obstruction and mesenteric inflammation, even in the absence of a confirmed infectious or autoimmune trigger.

Clinical Presentation and Initial Evaluation

The patient, a 56-year-old male with no significant medical history or prior surgeries, presented to the emergency department after five days of progressive abdominal symptoms.

Symptomatology and Physical Findings

• Primary Symptoms: Severe abdominal pain, diaphoresis, nausea, and vomiting.

• Intake Status: Inability to tolerate oral intake for 48 hours prior to admission.

• Physical Examination:

• Mild tachycardia and diaphoresis.

• Normotensive status.

• Abdominal distension with diffuse tenderness.

• Initial absence of peritoneal signs, though peritonitis developed within 24 hours of admission.

Laboratory and Imaging Results

Initial laboratory assessments revealed mild leukocytosis (WBC 14 K) and electrolyte imbalances, specifically hypochloremia, hyponatremia, and hypokalemia. Following fluid resuscitation, the WBC count rose to 16 K.

Feature	Findings
Bowel State	Severely dilated proximal small bowel and stomach
Mesentery	Extensive inflammatory changes and fat stranding throughout the proximal mesentery
Vascular Proximity	Inflammation concentrated around the superior mesenteric artery (SMA)
Distal Anatomy	Normal appearance of distal and colonic mesentery and fat

Surgical Intervention and Pathology

Due to the development of peritonitis and worsening clinical indicators, an emergent laparotomy was performed.

Operative Findings

• Lymphadenopathy: Multiple enlarged, necrotic mesenteric lymph nodes were identified. Purulent material was observed draining from the capsules of these nodes.

• Necrosis and Thrombosis: Significant portions of the proximal mesenteric fat were necrotic. This process led to vascular occlusion and thrombosis of side branches originating from the superior mesenteric artery.

• Intestinal Impact: The proximal jejunum was dusky and dilated, indicating ischemia. The duodenum and distal small bowel/colon remained viable and unaffected.

Surgical Procedure

1. Resection: The ischemic small bowel and its associated mesentery were excised down to the level of the superior mesenteric artery. This included the complete removal of necrotic lymph nodes and fat.

2. Staged Approach: The bowel was initially left in discontinuity with a temporary abdominal closure to allow for stabilization in the intensive care unit.

3. Reconstruction: A "second look" operation the following day confirmed the health of the remaining bowel. A duodenal-to-distal-jejunal anastomosis was then successfully performed.

Pathological Analysis

The pathology report confirmed the surgical findings, noting multiple necrotic lymph nodes and mesenteric fat with associated vascular occlusion. Key findings included:

• Absence of Malignancy: No neoplastic cells were identified.

• Granuloma Status: No evidence of non-caseating granulomas or other granulomatous formations.

• Ischemic Confirmation: Evidence of ischemic changes to the intestinal tissue.

Etiological Investigation and Differential Diagnosis

Despite the "fulminant" nature of the disease, the underlying cause could not be determined through standard diagnostic protocols.

Infectious Workup

All operative and blood cultures were negative for the following:

• Bacterial growth.

• Viral growth.

• Tuberculosis (TB).

• Fungal infections.

Autoimmune and Alternative Diagnoses

Given the sterile nature of the necrotic process, an extensive autoimmune and systemic evaluation was conducted.

Potential Etiology	Evidence/Results
Tuberculosis/Yersinia/Salmonella	Ruled out via negative cultures.
Systemic Lupus Erythematosus (SLE)	Ruled out; normal dsDNA and anti-nuclear antibodies.
Still’s Disease	Ruled out; absence of rash, arthritis, or typical systemic symptoms.
Kikuchi–Fujimoto Disease (KFD)	Ruled out; immunohistochemistry was inconsistent with KFD, which usually affects cervical nodes.
Rheumatoid Factor (RF)	Weakly positive, but deemed clinically irrelevant by rheumatology consultants.

The exact etiology of the necrotizing mesenteric lymphadenitis in this patient remains unknown, as the case did not align with the three previously reported adult cases in medical literature (which were linked to SLE, Still’s disease, and an unknown cause).

Clinical Outcome

The patient experienced a rapid post-operative recovery and was discharged on the sixth hospital day. Follow-up evaluations at six months and one year post-surgery indicated:

• No recurrence of the disease.

• Complete resolution of symptoms.

• Successful return to work and normal activities.

This case serves as a definitive example of how acute mesenteric lymphadenitis, though typically benign in children, can manifest as a fulminant necrotizing process in adults, requiring aggressive surgical intervention to prevent fatal bowel ischemia.