Multicentric vs. Unresectable Unicentric Castleman Disease with Active Presentation: An Orphan Rare Disease in a Young Egyptian Female Patient. A Case Report

Background: Castleman disease (CD) is a rare disorder that affects lymph nodes and has a wide range of associated symptoms. The affected lymph nodes show characteristic histological picture. Most of the unicentric Castleman disease (UCD) cases can be cured by complete surgical removal or radiotherapy, while multicentric CD (MCD) is much more complicated and have several subtypes and requires more effort to reach a precise diagnosis and management. Case presentation: A 17-years old female presented with sever fatigue and abdominal pain. Massive mediastinal lymphadenopathy was detected on radiological studies. Pathology confirmed a plasma cell variant of MCD. Autoimmune disorders, overlapping IgG4-related disease, TAFRO (Thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly) syndrome and other malignancies were excluded after a series of investigations. She was HIV-negative, and the human herpes virus-8 status was unknown. The final diagnosis of idiopathic MCD-not otherwise specified (iMCD-NOS) was reached. She showed a very good response to corticosteroids and monoclonal antibody course of treatment. Radiological investigations showed marked regression of the lymph node mass, and there was complete resolution of her symptoms and normalization of the hematological and biochemical parameters. Conclusion: The diagnosis and management of MCD remain very challenging, and the exclusion of infectious, autoimmune, and neoplastic disorders is necessary