type IV hypersensitivity disease plasma cell neoplasm heavy chain disease https://www.malacards.org/card/heavy_chain_disease MESH:D006362 HCD UMLS:C0018852 ICDO:9762/3 MedDRA:10019350 ICD9:273.2 GARD:0019074 SCTID:68979007 NCIT:C3082 MEDGEN:5469 ICD10CM:C88.3 ICD10CM:C88.2 DOID:0060125 heavy chain disease EFO:1001341 MONDO:0019464 Heavy-chain diseases (HCDs) are rare monoclonal lymphoplasma-cell proliferative disorders involving B cells and are characterized by the synthesis of truncated heavy chains without associated light chains. Orphanet:86864