Surreal illustration of a glowing lymph node in child's abdomen representing diagnosis of Kikuchi disease.

Uncommon Cause of Abdominal Pain: What You Need to Know About Kikuchi Disease

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Lena Kashyap in Health & Wellness December 2025 • 5 min read.

"A rare case study highlights Kikuchi disease presenting as abdominal pain in a young girl, emphasizing the importance of considering unusual causes for common symptoms."


Kikuchi disease, also known as histiocytic necrotizing lymphadenitis, is a rare, benign condition characterized by inflammation of the lymph nodes. It was first described in 1972 in Japan. While Kikuchi disease most commonly affects cervical (neck) lymph nodes, it can occasionally involve other areas of the body, including the abdomen. What makes this case particularly interesting is that it presented with abdominal pain, a less common symptom, which can lead to diagnostic challenges.

A recent case study published in the Korean Journal of Radiology sheds light on an unusual presentation of Kikuchi disease. The study details the case of a 7-year-old girl who presented with fever and left lower quadrant abdominal pain. Initial investigations, including an abdominal ultrasound, revealed a mass in her left lower abdomen, leading to suspicion of appendicitis or another intra-abdominal infection.

This article aims to explain this rare presentation of Kikuchi disease, the diagnostic process, and the key imaging findings that helped differentiate it from more common causes of abdominal pain. It is designed for general audience and medical students alike.

When Abdominal Pain Isn't What It Seems: Unmasking Kikuchi Disease

Surreal illustration of a glowing lymph node in child's abdomen representing diagnosis of Kikuchi disease.

The 7-year-old girl's symptoms began two weeks prior to her hospital visit with fever and sore throat. Initially, she was diagnosed with acute tonsillitis. Although her symptoms temporarily subsided with treatment, she experienced a recurrence of high fever (up to 38°C) predominantly at night, accompanied by pain in the left lower quadrant of her abdomen. This prompted further investigation and ultimately led to her referral to a different hospital.

Upon examination, doctors found tenderness and rebound tenderness in the left lower abdomen, indicating possible peritonitis (inflammation of the abdominal lining). Blood tests revealed an elevated white blood cell count (22,740/µl, normal range: 5000-14,500/µl) and elevated inflammatory markers, including an erythrocyte sedimentation rate (ESR) of 50 mm/hr (normal range: 0-30 mm/hr) and a C-reactive protein (CRP) level of 30.76 mg/L (normal range: 0.01-2.61 mg/L). These findings suggested an inflammatory or infectious process.

Imaging played a crucial role in diagnosing the patient, revealing:
  • Ultrasound: An ill-defined, 3-cm echogenic mass (appearing bright on the ultrasound) in the left iliac fossa (the lower part of the abdomen near the hip bone). The mass also contained an irregular fluid collection with internal echoes, suggesting inflammation or pus.
  • Computed Tomography (CT Scan): A CT scan confirmed the presence of a mass in the left iliac fossa, located in front of the external iliac vessels (major blood vessels in the pelvis). The mass showed heterogeneous enhancement (uneven brightness) after contrast injection, with a central area of low attenuation (appearing dark), suggestive of necrosis (tissue death).
Based on these findings, doctors initially suspected a possible intra-abdominal abscess (a collection of pus within the abdomen). However, a reconstructed coronal CT image (a view of the abdomen from front to back) revealed that the mass was located outside the peritoneal cavity (the space containing most abdominal organs), adjacent to the sigmoid colon (part of the large intestine). This led to consideration of an inflamed lymph node, possibly due to tuberculosis or Kikuchi disease.

A Rare but Important Consideration

While Kikuchi disease is a rare cause of abdominal pain, this case highlights the importance of considering it in the differential diagnosis, especially in young patients with fever and lymphadenopathy. Advanced imaging techniques like MDCT(Multi-Detector Computed Tomography) can help in the early diagnosis.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

Everything You Need To Know

1

What exactly is Kikuchi disease?

Kikuchi disease, also known as histiocytic necrotizing lymphadenitis, is a rare and benign condition characterized by inflammation of the lymph nodes. Typically, it affects cervical lymph nodes in the neck, but it can occur in other areas of the body, such as the abdomen, as seen in the case study. The disease was first identified in Japan in 1972. Its presentation can be quite varied, making diagnosis challenging, especially when it manifests with less common symptoms like abdominal pain.

2

Why is it important to consider Kikuchi disease when someone presents with abdominal pain?

The significance of considering Kikuchi disease lies in its potential to mimic other, more common conditions like appendicitis or intra-abdominal infections. If doctors don't consider it as a possibility, patients might undergo unnecessary treatments or surgeries. Accurate diagnosis, often aided by imaging techniques such as ultrasound and CT scans, is crucial to avoid mismanagement and ensure appropriate care.

3

How did imaging techniques help diagnose Kikuchi disease in the presented case?

In the case of the young girl, imaging techniques like ultrasound and CT scans were crucial. The ultrasound revealed an ill-defined mass in the left iliac fossa with internal echoes, suggesting inflammation. The CT scan confirmed the mass and showed heterogeneous enhancement with a central area of low attenuation, indicative of necrosis. A reconstructed coronal CT image further clarified that the mass was located outside the peritoneal cavity, adjacent to the sigmoid colon, leading doctors to consider inflamed lymph nodes due to tuberculosis or Kikuchi disease.

4

What do elevated white blood cell count, ESR, and CRP levels indicate?

Elevated white blood cell count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels are indicators of inflammation or infection in the body. In the described case, the patient's elevated white blood cell count (22,740/µl), ESR (50 mm/hr), and CRP level (30.76 mg/L) suggested an inflammatory process, which prompted further investigation to determine the underlying cause.

5

What is MDCT, and how does it help in diagnosing Kikuchi disease?

Multi-Detector Computed Tomography (MDCT) is an advanced imaging technique that provides detailed cross-sectional images of the body. It is valuable in diagnosing Kikuchi disease because it can help visualize affected lymph nodes and differentiate them from other conditions, such as abscesses or tumors. MDCT can show specific characteristics, like the location and enhancement patterns of the affected lymph nodes, aiding in accurate diagnosis and appropriate management.

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