Castleman disease is a rare, benign disorder of the lymph nodes that should be included in the differential diagnosis of anterior mediastinal masses. It is a lymphoproliferative disorder and is also known as angiofollicular lymph node hyperplasia, benign giant lymphoma, giant lymph node hyperplasia, and follicular lymphoreticuloma 1-3. It can occur anywhere in the body wherever there are lymph nodes. Approximately 70% of the cases are located in the thorax, 14% in the neck, 12% in the abdomen and 4% in the axilla 4.
The lesions in Castleman disease are predominantly of two histologic types: the hyaline vascular type and the plasma cell type. The majority of these lesions are of the hyaline vascular type, which accounts for approximately 90% of cases and is most often a localized disease 1.
On CT, the classic appearance of hyaline vascular Castleman disease is that of a solitary enlarged lymph node or localized nodal masses that demonstrate homogeneous intense enhancement after contrast material administration 5.
There are three patterns of involvement, including a solitary noninvasive mass (most common: 50% of cases), a dominant infiltrative mass with associated lymphadenopathy (40% of cases), and matted lymphadenopathy without a dominant mass (10% of cases)6.