[1273] Classical Hodgkin Lymphoma with Expression of T-Cell Markers and Associated T-Cell Receptor Gene Rearrangement – A Separate and More Aggressive Lymphoma with Features Intermediate between Classical Hodgkin Lymphoma and Anaplastic Large Cell Lymphoma?

A Alduaij, S Mangray, DO Treaba. Rhode Island Hospital, Lifespan, Providence, RI

Background: The current WHO classification identifies four histological subtypes of classical Hodgkin lymphoma (CHL). Holding a very characteristic immunophenotype, the vast majority of CHL cases are of B-cell lineage. A very small subset of CHL cases was reported to express T-cell marker (s) (5% in the study of Tzankov A et al., 2005) while genotypically <1% of the lesional cells were of T-cell lineage. In the differential diagnosis, anaplastic large cell lymphoma (ALCL) is always considered since in 3% of the cases it can have a “Hodgkin-like pattern”. We identified cases of CHL with aberrant expression of T-cell markers and correlate their morphological and immunophenotypical signature with molecular analysis, clinical presentation and response to therapy.
Design: 175 cases of classical Hodgkin lymphoma were retrieved from Rhode Island Hospital and the Miriam Hospital from 2000-09. There were 106 cases of nodular sclerosis (NS), 43 cases of mixed cellularity, 3 cases of lymphocyte rich CHL, 2 cases of lymphocyte depleted CHL, and 21 cases could not be further subclassified (NOS). In only 4 cases, the lesional cells were reported being positive for T-cell marker(s). Molecular studies for T-cell receptor gene rearrangements were performed on paraffin embedded tissue sections for these 4 cases.
Results: Morphologically 2 of the 4 cases were CHL-NS, while the other 2 were CHL-NOS, due to the small amount of tissue submitted at the initial diagnosis. In all 4 cases the lesional cells were CD45-, CD30+ and CD15+ and expressed at least a T-cell marker.

Table 1. Review of the CHL cases with expression of T-cell marker(s)

No.	Age	Sex	CHL	T-cell positive (IHC)	PCR	FISH	Stage
1	10	M	NS	CD4	TCR gamma gene rearrangement +	Negative for ALK rearrangement; positive for gain of 2p23	IIB
2	23	F	NS	CD3	TCR -	Not done	IIA
3	59	F	NOS	CD3, CD4, CD8	TCR -	Not done	IV
4	71	F	NOS	CD3, CD5, CD4, CD8	TCR beta gene rearrangement +	Not done	IV

Conclusions: We identified 4 cases of CHL with concomitant expression of T-cell marker(s), and 2 cases had also T-cell receptor gene rearrangements. In addition, 2 of these patients had a more aggressive clinical course with recurrence/progression of disease despite chemotherapy. We are questioning the existence of a possible separate and more aggressive lymphoma with features intermediate between classical Hodgkin lymphoma and ALCL.
Category: Hematopathology

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 205, Wednesday Morning