title: EBV-positive plasmacytoma of the submandibular gland--report of a rare case with molecular genetic characterization.
abstract: Plasmacytomas are differentiated plasma cell tumors that present as a mass lesion in osseous or extraosseous sites. Although the most common site for extramedullary plasmacytomas (EMP) is in the upper respiratory tract, plasmacytomas initially presenting as salivary gland masses are very uncommon. We describe a case of an EBV-positive plasmacytoma presenting as a 7.7 cm submandibular mass in an elderly immunocompetent man which displayed an abundance of "naked nuclei" on fine needle aspiration cytology. The tumor showed lambda light chain restriction and positive expression for CD38, MUM1 and EBER. Subsequent investigation for myeloma revealed absence of M-protein and end-organ damage, except for a lytic lesion in the radial bone. An extensive fluorescent in situ hybridization analysis showed the tumor to be negative for the t(4;14) FGFR3/IGH translocation as well as translocations involving the IGH,                         IGL, IGK, CCND1, BCL2, BCL6 and C-MYC genes. KRAS genetic analysis did not reveal any mutations of codons 12, 13 and 61.
authors: Department of Pathology, National University Health System, 5 Lower Kent Ridge Road, Singapore 119074, Singapore.
authors: Benedict
authors: B
authors: Yan
authors: Soo Yong
authors: SY
authors: Tan
authors: Ee Xuan
authors: EX
authors: Yau
authors: Siok Bian
authors: SB
authors: Ng
authors: Fredrik
authors: F
authors: Petersson
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000235:genetics / Q000378:metabolism; D000368:Aged; D044963:Biopsy, Fine-Needle; D015972:Gene Expression Regulation, Neoplastic; D004854:Herpesvirus 4, Human / Q000302:isolation & purification*; D006801:Humans; D050835:Interferon Regulatory Factors / Q000235:genetics / Q000378:metabolism; D008297:Male; D010954:Plasmacytoma / Q000378:metabolism* / Q000473:pathology / Q000821:virology*; D013365:Submandibular Gland Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000821:virology*; D000099218:Interferon Regulatory Factor-4
chemical_list: D051997:ADP-ribosyl Cyclase 1; D050835:Interferon Regulatory Factors; D000099218:Interferon Regulatory Factor-4