Breast implant‐associated, ALK‐negative, T‐cell, anaplastic, large‐cell lymphoma: Establishment and characterization of a model cell line (TLBR‐1) for this newly emerging clinical entity

BACKGROUND: Primary lymphomas of the breast are very rare (0.2‐1.5% of breast malignancies) and the vast majority (95%) are of B‐cell origin. Recently, 40 cases of clinically indolent anaplastic large‐cell kinase (ALK)‐negative, T‐cell, anaplastic, non‐Hodgkin lymphomas (T‐ALCL) have been reported worldwide. METHODS: A tumor biopsy specimen from a patient in this series was obtained for characterization. By using a human stromal feeder layer and IL‐2, a novel cell line, TLBR‐1, was established from this biopsy and investigated by using cytogenetics and various biomolecular methods. RESULTS: Immunoperoxidase staining of the tumor biopsy showed a CD30/CD8/CD4 coexpressing T‐cell population that was epithelial membrane antigen (EMA) + and perforin + . Multiplex polymerase chain reaction (PCR) of TCRγ genes showed monoclonality that suggested a T‐cell origin, yet pan‐T markers CD2/5/7, anaplastic large‐cell kinase (ALK)‐1, pancytokeratins, CD20, CD56, and Epstein‐Barr virus (EBV) by in situ hybridization (ISH) were negative. TLBR‐1 is IL‐2 dependent, has a relatively long doubling time (55 hours), and displays different cellular shapes in culture. Cytogenetic analysis of tumor and TLBR‐1 cells confirmed a highly anaplastic cell population with a modal number of 47 chromosomes lacking t(2;5). PCR screens for EBV and human T‐lymphotropic virus types 1 and 2 (HTLV‐1/2) were negative. Fluorescence‐activated cell‐sorting (FACS) analysis showed strong positivity for CD4/8, CD30, CD71, and CD26 expression, and antigen presentation (HLA‐DR + CD80 + CD86 + ), IL‐2 signaling (CD25 + CD122 + ), and NK (CD56 + ) markers, and Western blots demonstrated strong Notch1 expression. Severe combined immunodeficiency (SCID) mouse TLBR‐1 heterotransplants recapitulated the histology and marker characteristics of the original tumor. CONCLUSIONS: TLBR‐1, a novel ALK‐negative, T‐cell, anaplastic, large‐cell lymphoma, closely resembles the original biopsy and represents an important tool for studying this newly recognized disease entity. Cancer 2011. © 2010 American Cancer Society.