Recognizing puzzling PD1 + infiltrates in marginal zone lymphoma by integrating clonal and mutational findings: pitfalls in both nodal and transformed splenic cases

Table 1 Histological and molecular of MZL (or transformed MZL) with PD1-positive T-Cell expansions

	Case 1	Case 2	Case 3 (transformed)
Age (years)	70	75	47
Sex	Woman	Man	Man
Biopsy Location	left cervical lymph node	right groin lymph node	right cervical LN
B cells
CD20	+	+	-
PAX5	+	+	-
CD19	NA	NA	+
CD22	NA	NA	+
CD10	-	-	-
BCL6	-	-	-
CD30	-	-	+
B cell size/Pattern	Small-medium /Diffuse	Small-medium/Nodular and disseminated	Medium-Large /Scattered
T cells
CD3	+	+	+
CD4	+	+	+
CD8	subset +	subset +	subset +
CD2	+	+	+
CD5	+	+	+
CD7	+	+	+
PD1	+	+	+
CD10	Minor subset +	-	-
BCL6	+	subset +	Minor subset +
CXCL13	NA	+	Minor subset +
PD-1 positive T-cell localization	Reactive-like Pattern	Follicular Pattern peripheral and central mixed	Diffuse Pattern
CD21 + FDC cells	follicular	extrafollicular	Absent
EBER1/2	Rare	Rare	Negative
IG rearrangement	Monoclonal	Monoclonal	Monoclonal
TCR rearrangement	Polyclonal	Polyclonal	Polyclonal

ISSN: 1746-1596