ABSTRACT
Overview 101 Angioimmunoblastic lymphoma 102 Histology 103 Immunohistochemistry 104 Genetics 104 Differential diagnosis 106 Anaplastic large cell lymphoma 107 Histology 108 Immunohistochemistry 109 Genetics 112 Differential diagnosis 113 Peripheral T-cell lymphoma not otherwise specified 113 Histology 113 Recognized variants of peripheral T-cell lymphoma
not otherwise specified 114 Immunohistochemistry 115 Genetics 116 Differential diagnosis 116 Adult T-cell leukaemia/lymphoma 116 Histology 117 Immunohistochemistry 118
Genetics 118 Differential diagnosis 118 T-cell prolymphocytic leukaemia 118 Histology 119 Immunohistochemistry 119 Genetics 119 Differential diagnosis 119 Mycosis fungoides and Sézary syndrome 120 Histology 120 Immunohistochemistry 120 Genetics 121 Enteropathy-type T-cell lymphoma (enteropathy-
associated T-cell lymphoma) 121 Histology 121 Immunohistochemistry 122 Differential diagnosis 122 T-cell leukaemias and related systemic disorders 122 Aggressive NK-cell leukaemia 122 Epstein-Barr virus-positive T-cell lymphoproliferative
disorders of childhood 122 References123
T-cell neoplasms are less common than B-cell lymphomas and their incidence shows both geographical and racial variations. In the International Non-Hodgkin Lymphoma Classification Study of cases from the United States, Europe, Asia and South Africa, peripheral T-cell lymphomas accounted for 7.6 per cent of the total, with anaplastic large cell lymphoma (ALCL) forming an additional 2.4 per cent (Non-Hodgkin’s Lymphoma Classification Project 1997). T-cell lymphomas are more common in Asia and there is a high incidence of nasal-type natural killer (NK)/T-cell lymphomas in Asian races. In parts of Japan and the Caribbean, the increased incidence of adult T-cell leukaemia/lymphoma (ATLL) is related to the high prevalence of infection by the human T-cell lymphotrophic virus 1 (HTLV-1).
