The purpose of this study is to determine the uptake of the imaging agent \[68Ga\]-pentixafor with PET/CT scans in people with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and non-Hodgkin lymphoma (NHL), or you have histiocytic neoplasms (Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD) and/or Rosai-Dorfman disease (RDD).
Indolent B- or T-cell Non-Hodgkin lymphoma (including cutaneous lymphomas) or Non-Hodgkin lymphoma with variable FDG uptake and clinical course, such as mantle cell lymphoma; and measurable disease according to Lugano criteria
Histiocytic neoplasms (Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD) and/or Rosai-Dorfman disease (RDD)
MGUS/SMM or MM according to IMWG definitions
Solid tumors, such as lung cancers, meningioma, adrenocortical neoplasms including cortisol-producing adenomas or high suspicion for tumor, such as in patients with Cushing's disease.
Breast-feeding
History of renal functional disorders (chronic kidney disease with eGFR<30)
Refusal or inability to tolerate the scanning procedure (e.g., due to claustrophobia)