Unicentric Castleman disease was misdiagnosed as pancreatic mass: A case report.

Background: Castleman's disease (CD) is a lymphatic proliferative disorder of unknown cause and is rarely seen clinically. It has been divided into unicentric and multicentric types. Unicentric CD (UCD) occurs as a solitary enlarged mass and mediastinal lymph nodes are the most common site. Surgical excision has proven to be curative for UCD. Multicentric CD (MCD) appears as a systemic disease with peripheral lymphadenopathy. MCD had a poor response to surgery and monoclonal antibodies with rituximab have become a research hotspot.

Case Summary: A 44-year-old woman presented with a pancreatic mass during routine physical examination. She had no obvious symptoms, such as fever, abdominal pain, abdominal distension, or jaundice. Ultrasound examination indicated a hypoechoic mass between the body of the pancreas, left lobe of the liver and stomach. It had a clear boundary, irregular shape, uneven echo, and no obvious blood flow signals. To clarify the diagnosis, contrast-enhanced ultrasound examination was performed, which showed a benign pancreatic lesion. Neuroendocrine or solid pseudopapillary tumor was a possible diagnosis. The patient underwent further contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging, which were suggestive of solid pseudopapillary tumor or neuroendocrine tumor. All the examinations failed to give a definitive diagnosis, and the patient underwent surgery. The final pathological and immunohistochemical results showed that the mass was CD.

Conclusion: This case highlights when lymphadenopathy is encountered clinically, CD should be considered and a biopsy should be performed.