Table 1.

Clinical and pathological characteristics of included patients.

Case number	Sex/Age at diagnosis	Ann Arbor Stage	Pattern	T-cell phenotype or TFH phenotype	Epstein-Barr virus-encoded RNA (EBER)	Management	Follow-up	Status at last follow-up
Case 1	Male/ 64	I	AITL patterns 1 & 2	CD4 + , PD1 + , ICOS+	Negative	Surgical excision of single site of involvement and observation	5 years	Alive
Case 2	Male/ 69	II	AITL pattern 1	CD4 + , PD1 + , ICOS+	Negative	Observation	5 years	Alive
Case 3	Female/ 70	I	AITL pattern 1	CD4 + , CD10 + , PD1 + , ICOS+	Scattered positive	Excisional LN biopsy of single site of disease	5 years	Alive
Case 4	Female / 72	I	AITL pattern 1	PD1 + , ICOS+	EBER+ in large B cell immunoblasts	Observation	3 years	Alive
Case 5	Female / 67	III	AITL pattern 1	CD4+ PD1 + ICOS +	Positive	Observation	6 years	Alive
Case 6	Female / 42	III	AITL pattern 1	CD4+ PD1 + ICOS +	Positive	Observation	5 years	Alive
Case 7	Female / 52	II	AITL patterns 1 & 2	ICOS+ PD1+	Positive	Prednisolone and paracetamol	5 years	Alive
Case 8	Female / 74	IV	AITL pattern 1	CD4 + CD5-a	Positive	Prednisolone for concomitant diagnosis of ILD	6 years	Deceased
Case 9	Female / 78	II	AITL pattern 3	CD4 CD10+ BCL6+ PD1+	Positive	Prednisolone	22 months	Deceased

^aCD4 + T-cells with CD5 loss are present in peripheral areas of germinal centers in keeping with a neoplastic Tfh population. Prominent high endothelial venules and presence of focal areas of follicular dendritic cell expansion are seen.