Molecular Basis of Langerhans and Non-Langerhans Cell Histiocytic Neoplasms and Castleman Disease

Inclusion Criteria

• •Must have histopathologic confirmation of the particular rare hematologic disease.
• •Diseases that will be considered as rare hematologic diseases for this study will include the following
• •* Langerhans cell histiocytosis (LCH)
• •* Erdhiem Chester disease (ECD)
• •* Rosai-Dorfman disease (RDD)
• •* Miscellaneous histiocytic entities -indeterminate dendritic cell tumor, interdigitating dendritic cell sarcoma, follicular dendritic cell sarcoma, fibroblastic reticular cell tumor
• •* Unicentric Castleman disease
• •* Multicentric Castleman disease including TAFRO
• •* Follicular Dendritic Cell sarcoma (FDCS)
• •Newly diagnosed treatment naïve patients as well as patients who received prior therapies (e.g. chemotherapy, targeted therapy, surgery, or radiation) will be included. -Tissue specimens collected within the past 5 yearse will be considered acceptable for study inclusion will include the following
• •Collected as part of the evaluation for diagnostic confirmation
• •Tissue specimen or extracted DNA (from blood sample) banked in IRB approved tissue repositories and obtained within five years prior to the date of informed consent. -Tissue samples are planned to be collectedfrom previously stored surgical specimens already being stored in pathology lab
• •Consent to have germline testing performed in parallel to tumor testingg)Patients willing to receive treatmen