Table I.

Pathology specimens (lymph nodes, bone marrow, skin), morphology, flow cytometry, cytogenetics, and genomic profiling/biomarker analysis

Specimen	Morphology	Flow cytometry	Cytogenetics
Right inguinal node	Reactive follicular hyperplasia, clusters of plasma cells with mature morphology	κ-preponderant (κ:λ ratio of 3:1) B cells (43%); T cells exhibit increased CD4:CD8 ratio at 9:1	3 copies of MALT1
Bone marrow	No morphologic evidence of lymphoma	Monotypic κ-restricted B-cell population identified CD19+, CD20+, CD22+, CD23+, CD25+, FMC7+ CD5−, CD10−, CD11c−, CD103−	N/A
∗Left inguinal node	Follicular hyperplasia with marked polyclonal plasmacytosis	Monotypic κ-restricted B cells, CD5+, CD19+, CD20+, CD22+, partial CD23+, partial FMC7+, CD10−, CD38−, EBER−, ISH−, HHV8−, Ki67 high	N/A
Bone marrow	IgM(+) plasma cell neoplasm involving hypercellular marrow with trilineage hematopoiesis. No B-lineage cells present.	No definitive B cells and plasma cells; 8.4% small mature T cells with CD4:CD8 ratio of 2.8:1; 1.1% NK cells.	Normal male karyotype
Skin	Interstitial neutrophilic infiltrate with epitheliotropism. No vasculitis.	N/A	N/A

Comprehensive genomic profiling and biomarker analysis
Test	Findings
Tissue NGS of lymph node∗†	MAP2K1 P124S MYD88 L265P ARID1A D1810fs∗† DNMT3A R736C
Blood cfDNA‡	TP53 L145P (0.2% cfDNA) TERT promoter SNV (7.7% cfDNA)
TMB†	1 mutation/mb
PD-1/L1 IHC of lymph node tumor cells§	PD-1 expression: low positive PD-L1 expression: Negative

cfDNA, cell free DNA; EBER, Epstein Barr virus–encoded small RNAs; HHV8, human herpes virus 8; IHC, immunohistochemistry; ISH, in-situ hybridization; NGS, next-generation sequencing; NK, natural killer; PD, programmed death receptor; TMB, tumor mutational burden.

^∗Tissue NGS done on left inguinal lymph node as noted.

^†Performed by Foundation One Heme panel (406 gene panel).

^‡Performed by Guardant 360 (73 gene panel).

^§Performed by Pathline emerge using clone NAT105 for PD-1 staining and clone SP142 for PD-L1 staining.