Transformation of Sézary syndrome into CD30+ anaplastic large T-cell lymphoma after alemtuzumab therapy with evidence of clonal unity

Alemtuzumab-induced Alopecia areata - a case report and systematic literature review of adverse events associated with Alemtuzumab

Alemtuzumab is currently approved for the treatment of active relapsing-remitting multiple sclerosis (RRMS). Despite the efficacy of this therapy several side effects in the skin have been noted during or after infusion including vitiligo, alopecia areata, malignant skin tumors and infections. Awareness of these effects and their treatment is of essential interdisciplinary importance. This minireview provides an overview of the dermatological side effects described in the current literature. We also suggest pathomechanisms underlying these phenomena. To introduce this review, we present the case of a woman with RRMS who developed severe alopecia areata for the first time on alemtuzumab.

A Systematic Approach to the Cutaneous Lymphoid Infiltrates: A Clinical, Morphologic, and Immunophenotypic Evaluation

CONTEXT.—

The evaluation of cutaneous lymphoid infiltrates, both neoplastic and inflammatory, occurs very frequently in routine dermatopathologic examination and consultation practices. The "tough" cutaneous lymphoid infiltrate is feared by many pathologists; skin biopsies are relatively small, whereas diagnostic possibilities are relatively broad. It is true that cutaneous lymphomas can be difficult to diagnose and that in many circumstances multiple biopsies are required to establish a correct diagnostic interpretation. As a reminder, one should understand that low-grade cutaneous lymphomas are indolent disorders that usually linger for decades and that therapy does not result in disease cure. It is also important to remember that in most circumstances, those patients will die from another process that is completely unrelated to a diagnosis of skin lymphoma (even in the absence of specific therapy).

OBJECTIVE.—

To use a clinicopathologic, immunophenotypic, and molecular approach in the evaluation of common lymphocytic infiltrates.

DATA SOURCES.—

An in-depth analysis of updated literature in the field of cutaneous lymphomas was done, with particular emphasis on updated terminology from the most recent World Health Organization classification of skin and hematologic tumors.

CONCLUSIONS.—

A diagnosis of cutaneous lymphoid infiltrates can be adequately approached using a systematic scheme following the proposed ABCDE system. Overall, cutaneous T- and B-cell lymphomas are rare and "reactive" infiltrates are more common. Evaluation of lymphoid proliferations should start with a good sense of knowledge of the clinical presentation of the lesions, the clinical differential considerations, and a conscientious and appropriate use of immunohistochemistry and molecular tools.

Clonotypic Diversity of the T-cell Receptor Corroborates the Immature Precursor Origin of Cutaneous T-cell Lymphoma

PURPOSE

Mycosis fungoides is one of the most common types of extranodal T-cell lymphomas, considered to be caused by malignant transformation of the mature T cells residing in the skin. However, some clinical observations such as the multifocal distribution of mycosis fungoides lesions or patterns of relapse after radiotherapy are not readily explainable by the mature T-cell origin theory.

EXPERIMENTAL DESIGN

We have performed a detailed analysis of T-cell receptor (TCR) rearrangements in single malignant cells and in biopsies from mycosis fungoides tumors composed of >80% of malignant cells using next-generation sequencing (NGS) to pinpoint the relationship between neoplastic cells in mycosis fungoides. We have also aimed to detect malignant, circulating T-cell by whole blood TCR sequencing.

RESULTS

We found a substantial clonal heterogeneity in the mycosis fungoides samples with regards to TCR, and we demonstrated that lymphoma cells harboring identical TCRγ sequences may harbor different TCRα and β sequences. Lack of absolute TCRα, -β, -γ monoclonality was further confirmed by TCR amplification and sequencing from microdissected lymphoma cells. We have also found the TCR rearrangements characteristic for lymphoma cells in patients' peripheral blood despite the lack of leukemic blood involvement; however, the circulating TCRγ clonotype did not always represent the dominant cutaneous clonotype.

CONCLUSIONS

These findings can be explained by a model where malignant transformation takes place during early T-cell development giving rise to circulating premalignant clones, which home to the skin producing clinically apparent lesions of cutaneous lymphoma. Therapeutic strategies in T-cell lymphoma should therefore target those early lymphoma precursor cells.

Antibody-Based Therapies for Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphomas (CTCLs) are a group of non-Hodgkin's lymphomas that present in the skin. In early-stage disease, the course is generally chronic and indolent; however, in advanced stages of disease, therapies rarely provide long-lasting responses, and the only potential curative therapy is allogeneic hematopoietic stem-cell transplantation. This has led to the search for novel targeted therapies to better treat more advanced stages of CTCLs that cannot be controlled by typical treatment regimens. One area of advancement has been the development of antibodies specifically targeted to cell types that are known to be involved in CTCL. At present, brentuximab vedotin, an antibody-drug conjugate composed of an anti-cluster of differentiation (CD)-30 antibody covalently linked to monomethyl auristatin E, is approved for the treatment of CD30+ lymphoproliferative disorders [lymphomatoid papulosis (LyP) and primary cutaneous-anaplastic large-cell lymphoma (pc-ALCL)] as well as transformed CD30+ mycosis fungoides (MF). Additionally, mogamulizumab, an anti-chemokine receptor 4 (CCR4) monoclonal antibody, is approved for patients with MF or Sézary syndrome (SS) for whom one prior systemic therapy has failed. Trials are underway looking into the use of immune checkpoint inhibitors in the treatment of CTCLs. As we continue to research CTCL, and as antibody-based therapies continue to advance, more antibody-specific targeted therapy could provide alternative treatment regimens for patients with advanced CTCL.