Thrombocytosis and erythropoietin-unresponsive anemia in patients with Castleman's disease

Angiofollicular lymph node hyperplasia (Castleman's disease)

This review provides a comprehensive assessment of angiofollicular lymph node hyperplasia (ALNH) or Castleman's disease including pathogenesis, clinical presentation, histomorphologic and immunophenotypic findings, laboratory results, treatment, and prognosis. A division of ALNH into clinically relevant subtypes provides a framework for the consideration of the disorder. A comprehensive search of the medical literature involving ALNH using Medline was performed. Reports judged to be significant for the understanding of the disorder were analyzed and their findings incorporated into this review. ALNH is divided into localized/unicentric ALNH and generalized/multicentric ALNH due to the profound clinical differences seen between these variants. Localized/unicentric ALNH is separated by clinical and histomorphologic criteria into hyaline-vascular (HV) and plasma-cell (PC) subtypes. Generalized/multicentric ALNH may be divided by clinical criteria into generalized/multicentric ALNH without neuropathy (non-neuropathic) and generalized/multicentric ALNH with neuropathy (POEMS-associated or neuropathic). The dichotomy between these two subtypes is not absolute, with considerable clinical overlap occurring among patients presenting with generalized disease. Immunophenotypic and molecular probe studies demonstrate clonal B-cell lymphocyte populations in some cases, particularly those with generalized/multicentric ALNH. However, the finding of clonal populations is of no value in predicting malignant clinical progression. We conclude that using this division of ALNH, patients presenting with symptoms and histomorphology consistent with ALNH can be subdivided into the appropriate category of ALNH. Localized or unicentric disease, either HV or PC subtype, has an excellent prognosis with surgery being curative in the majority of cases. Generalized or multicentric disease indicates a poor prognosis with short survival, with the neuropathic variant possessing resistance to steroids and chemotherapy and a corresponding worse prognosis.