Systemic CD30+ T cell lymphoma usually composed of cohesive large cells witih abundant cytoplasm and pleomorphic nuclei; half or more express anaplastic lymphoma kinase (ALK1)
Alternate/Historical Names
Anaplastic large cell lymphoma (T/null cell type)
Ki-1 lymphoma (included some cases of diffuse large B cell lymphoma)
Diagnostic Criteria
Cohesive large cells with abundant cytoplasm and pleomorphic nuclei
Hallmark cells (“horseshoe cells”)
Characteristic large cells with U-shaped or C-shaped nuclei surrounding a brightly eosinophilic Golgi area
Most frequent in the common variant
Scattered hallmark cells usually also found in small cell, lymphohistiocytic and other variants
Cohesive growth pattern
Intrasinusoidal growth in lymph nodes (if lymph node is not effaced)
Numerous histological variants have been described, and may coexist
Common variant
large anaplastic cells with abundant eosinophilic cytoplasm and pleomorphic nuclei
Small cell variant
Smaller cells with less irregular nuclei than common variant
Hallmark cells in perivascular location
Lymphohistiocytic variant
Predominance of histiocytes
Hallmark cells in perivascular location
Less common subtypes: neutrophil-rich, giant cell rich, signet ring, sarcomatoid, Hodgkin-like with nodular sclerosis
T cell or “null cell” immunophenotype
Lack of B cell or classical Hodgkin immunophenotype
ALK1 immunopositivity/ALK1 translocation is definitional in this setting, but is absent in up to 40% of cases
It is debated by some experts that ALK1-negative cases should be classified as peripheral T-cell lymphoma, NOS
Warnke RA, Weiss LM, Chan JKC, Cleary ML, Dorfman R . Tumors of the Lymph Nodes and Spleen, Atlas of Tumor Pathology, AFIP Third Series, Fascicle 14, 1995.
Jaffe ES, Harris NL Stein H, Vardiman JW eds. Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues, World Health Organization Classification of Tumours 2001.
d'Amore ES, Menin A, Bonoldi E, Bevilacqua P, Cazzavillan S, Donofrio V, Gambini C, Forni M, Gentile A, Magro G, Boldrini R, Pillon M, Rosolen A, Alaggio R. Anaplastic large cell lymphomas: a study of 75 pediatric patients. Pediatr Dev Pathol. 2007 May-Jun;10(3):181-91.
Benharroch D, Meguerian-Bedoyan Z, Lamant L, et al. ALK-positive lymphoma: a single disease with a broad spectrum of morphology. Blood. 1998;91:2076–2084
Kesler MV, Paranjape GS, Asplund SL, McKenna RW, Jamal S, Kroft SH. Anaplastic large cell lymphoma: a flow cytometric analysis of 29 cases. Am J Clin Pathol. 2007 Aug;128(2):314-22.
Medeiros LJ and KSJ Elenitoba-Johnson. Anaplastic Large Cell Lymphoma. Am J Clin Pathol 2007;127:707-722