[Idiopathic multicentric Castleman's disease]

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder.
• iMCD shares clinical, radiological, and pathological similarities with IgG4-related disease and other lymphadenopathies.
• Cytokine dysregulation, particularly elevated interleukin-6, drives systemic inflammation and lymphadenopathy in iMCD.

Purpose of the Study:

• To review the diagnostic criteria for idiopathic multicentric Castleman disease.
• To present two cases of iMCD, including a novel instance of extranodal hip muscle involvement.
• To enhance understanding of the clinical, laboratory, and morphological features aiding iMCD diagnosis.

Main Methods:

• Literature review of idiopathic multicentric Castleman disease.
• Case report analysis of two patients diagnosed with iMCD.
• Histopathological examination of lymph node and extranodal tissue.

Main Results:

• Idiopathic multicentric Castleman disease diagnosis requires exclusion of HHV-8 and HIV infections.
• Histological findings in iMCD can mimic reactive, tumoral, or IgG4-related lymphadenopathy.
• The study reports the first known case of extranodal hip muscle involvement in iMCD.

Conclusions:

• Accurate diagnosis of iMCD relies on a comprehensive evaluation of clinical, laboratory, and morphological data.
• Distinguishing iMCD from similar conditions necessitates careful exclusion of infectious etiologies.
• Recognition of extranodal manifestations, such as hip muscle involvement, expands the understanding of iMCD's presentation.