T-cell/NK-cell lymphomas: A review

Uncommon Variants of Mature T-Cell Lymphomas (MTCLs): Imaging and Histopathologic and Clinical Features with Updates from the Fourth Edition of the World Health Organization (WHO) Classification of Lymphoid Neoplasms

Simple Summary

Familiarity with the updated fourth edition WHO classification of lymphoid malignancies released in 2016, and the new terminology introduced, is crucial for oncologists, pathologists and radiologists. It is mandatory to be aware of rare variants of T-cell lymphomas, specifically mature T-cell lymphomas, including clinicopathologic keys and the most common imaging features and sites of involvement for each subtype. Even though some of these disorders may have perceptible clinical and imaging features, they may overlap with more common disorders, causing delay in diagnosis and treatment. Understanding the appropriate clinical setting and imaging findings will help radiologists to include these disorders in their differential diagnosis. Imaging plays a pivotal role in subclassifying these subtypes of MTCLs, affecting prognosis and treatment implications. Many of these disorders if diagnosed early can be potentially treatable, and early, aggressive intervention may be lifesaving.

Abstract

Understanding the pathogenesis and molecular biology of malignant lymphomas is challenging, given the complex nature and incongruity of these disorders. The classification of lymphoma is continually evolving to account for advances in clinical, pathological, molecular biology and cytogenetic aspects, which impact our understanding of these disorders. The latest fourth edition of the WHO classification of lymphoid malignancies was released in 2016 to account for these changes. Additionally, unlike B-cell lymphomas (BCL), T-cell lymphomas (TCL) are uncommon, and may be sporadically experienced in clinical practice. These disorders are rare, thus early diagnosis is challenging for both physicians and radiologists, owing to the overlap in clinical and imaging features with other, more common disorders. We aim to discuss some rare variants of T-cell lymphomas, including clinicopathologic and imaging features, as well as to give a glimpse of the updates contained within the new 2016 WHO classification.

Molecular mechanism of myofibroblast formation and strategies for clinical drugs treatments in hypertrophic scars

Hypertrophic scars (HTS) commonly occurred after burn and trauma. It was characterized by the excessive deposition of extracellular matrix with the inadequate remodeling, which could result in severe physiological and psychological problems. However, the effective available prevention and treatment measures were still limited. The main pathological feature of HTS was the excessive formation of myofibroblasts, and they persist in the repaired tissue. To better understand the mechanics of this process, this review focused on the characteristics and formation of myofibroblasts, the main effector cells in HTS. We summarized the present theories and opinions on myofibroblasts formation from the perspective of related signaling pathways and epigenetic regulation, such as DNA methylation, miRNA/lncRNA/ceRNA action, histone modification, and so forth for a better understanding on the development of HTS. This information might assist in developing effective experimental and clinical treatment strategies. Additionally, we also summarized currently known clinical strategies for HTS treatment, including traditional drugs, molecular medicine, stem cells, and exosomes.

T-Cell Non-Hodgkin Lymphomas: Spectrum of Disease and the Role of Imaging in the Management of Common Subtypes

T-cell non-Hodgkin lymphomas (NHLs) are biologically diverse, uncommon malignancies characterized by a spectrum of imaging findings according to subtype. The purpose of this review is to describe the common subtypes of T-cell NHL, highlight important differences between cutaneous, various peripheral and precursor subtypes, and summarize imaging features and the role of imaging in the management of this diverse set of diseases.

Unusual skin lesions mimicking bruises caused by Pseudomonas septicemia secondary to undiagnosed peripheral T-cell lymphoma in a young woman

We present a case of a 30-year-old woman with learning difficulties who was found dead at home by her mother. Her body was partially naked and covered in a number of unusual skin lesions with a targetoid appearance with red erythematous centers and well-delineated halos of pallor. These lesions were initially thought to be bruises by the police and by a forensic postmortem instigated. Postmortem examination also identified hepatosplenomegaly, severe lymphadenopathy, and focal patchy colonic ulceration. Histologic examination of the skin and bowel ulcers showed the lesions to be areas of infarction caused by Pseudomonas aeruginosa vasculitis. Pseudomonas was also cultured from the swabs of the abdomen, the spleen, and the blood cultures. Histologic findings of the lymph nodes showed complete effacement of the normal architecture by a population of pleomorphic small lymphoid cells. Immunohistochemistry confirmed the predominant cell type to be T-cells. The diagnosis of peripheral T-cell lymphoma was made. The cause of death was given as Pseudomonas septicemia secondary to immunocompromise resulting from the undiagnosed peripheral T-cell lymphoma. The pathogenesis of Pseudomonas and its association with malignancy is discussed along with a brief review of peripheral T-cell lymphomas. This case report demonstrates the characteristic macroscopic appearance of cutaneous Pseudomonas-associated lesions and how they can be misinterpreted as bruises.

CT and PET/CT findings of T-cell lymphoma

OBJECTIVE

The purpose of this study was to describe the extranodal features of T-cell lymphoma at CT and PET/CT.

CONCLUSION

The extranodal features of T-cell lymphoma are not specific and usually cannot be used to differentiate T-cell lymphoma from other aggressive types of lymphoma. Noncutaneous subtypes frequently manifest with visceral involvement. The goal of CT in initial staging is to exclude visceral involvement. Evidence on the utility of PET/CT is promising, showing high diagnostic value in evaluation of occult disease and treatment response, but the role of PET/CT is evolving.