Rare aggressive natural killer cell leukemia presented with bone marrow fibrosis - a diagnostic challenge

tp53 deficiency causes a wide tumor spectrum and increases embryonal rhabdomyosarcoma metastasis in zebrafish

The TP53 tumor-suppressor gene is mutated in >50% of human tumors and Li-Fraumeni patients with germ line inactivation are predisposed to developing cancer. Here, we generated tp53 deleted zebrafish that spontaneously develop malignant peripheral nerve-sheath tumors, angiosarcomas, germ cell tumors, and an aggressive Natural Killer cell-like leukemia for which no animal model has been developed. Because the tp53 deletion was generated in syngeneic zebrafish, engraftment of fluorescent-labeled tumors could be dynamically visualized over time. Importantly, engrafted tumors shared gene expression signatures with predicted cells of origin in human tissue. Finally, we showed that tp53^del/del enhanced invasion and metastasis in kRAS^G12D-induced embryonal rhabdomyosarcoma (ERMS), but did not alter the overall frequency of cancer stem cells, suggesting novel pro-metastatic roles for TP53 loss-of-function in human muscle tumors. In summary, we have developed a Li-Fraumeni zebrafish model that is amenable to large-scale transplantation and direct visualization of tumor growth in live animals.

Aggressive natural killer cell leukemia or extranodal NK/T cell lymphoma? a case with nasal involvement

Background

Aggressive natural killer cell leukemia/lymphoma (ANKL) is a rare and highly aggressive NK cell neoplasm with a short clinical course and poor prognosis and is often misdiagnosed and confused with NK/T cell lymphoma (NKTL), which has a very different prognosis. Here, we present a case with nasal and bone marrow involvement, provide a literature review and make a differential diagnosis.

Case presentation

A 41-year-old male presented nasal congestion pharyngalgia, palatal perforation, high fever and multiorgan dysfunction. Our diagnosis primarily relied on clinical features, the morphology and immunophenotype of the neoplastic cells and imaging studies. Characteristic large granular lymphocytes with azurophilic granules were visible in the bone marrow smears. In addition, the neoplastic cells expressed a typical immunophenotype, and the T cell receptor γ (TCR-γ) gene rearrangement analysis and presence of Epstein-Barr virus (EBV) were negative. The patient’s symptoms and signs were temporarily relieved after chemotherapy treatment, but after a short time, he underwent a rapid clinical decline and died 8 weeks later after admission due to multiorgan function failure.

Conclusion

Our case demonstrates that to avoid a misdiagnosis, bone marrow analyses and other examinations should be performed early when a patient initially presents nasal lesions and other systemic symptoms. To the best of our knowledge, this may be the first reported case of ANKL with sternal tenderness.

Aggressive NK-cell leukemia in a 69 years old Caucasian woman: a case report

Aggressive NK-cell leukemia is a rare malignancy mostly seen in younger Asians with a rapid clinical course and poor prognosis. Here, we describe a 69 years old Caucasian woman presenting with massive leukemization of neoplastic NK-cells. The cells were abnormal in morphology and surface marker expression and this clearly distinguished them from their normal counterpart. They were large and variable in shapes with irregular folding of the nuclei. By flow cytometry, their light scatter characteristics resembled normal monocytes. They showed bright expression of CD56 and CD2 but markedly decreased expression of CD7. They also expressed CD25. The patient presented with general malaise, including high fever, abdominal pain, signs and haemophagocytosis, and she quickly deteriorated and died 11 days after hospitalization. The origin of the leukemic cells of aggressive NK-cell leukemia is most likely the relatively scarce population of CD56^bright NK-cells, primarily residing lymph nodes and tonsils. The immunophenotype of the case presented here support this, adding CD25 expression which is not earlier addressed in this entity.

Influence of fingolimod on basic lymphocyte subsets frequencies in the peripheral blood of multiple sclerosis patients - preliminary study

Background

Fingolimod is a drug administered orally to adult patients treated for relapsing remitting course of multiple sclerosis (MS). Mode of action of fingolimod is based on intense S1P1 receptor stimulation and “arresting” lymphocytes in lymphatic organs. Objective of the research was to assess changes in the frequencies of basic lymphocyte subsets in patients treated for multiple sclerosis with the use of fingolimod.

Material and methods

Study group comprised of 25 previously untreated adult patients with MS. Venous blood samples were collected from each patient before and one month, three months and six months after treatment initiation. Peripheral blood lymphocyte immunophenotype was assessed with a set of monoclonal antibodies bounded to appropriate fluorochromes and flow cytometer FACSC alibur. Statistical analysis of the results was conducted using Statistica 9.0 software.

Results

Before fingolimod administration median of lymphocyte subsets percentage in each patient was in reference range. After 1 month of treatment we noticed significant changes in frequencies of following lymphocyte subsets: NK cells – 51.22% (p = 0.016), T CD4+ cells – 11.58% (p = 0.01), T CD4+:T CD8+ cells ratio – 0.61 (p = 0.005). After 3 and 6 months of treatment there was further increase of deviation from normal state.

Conclusions

The use of fingolimod is associated with profound changes in lymphocyte subsets distribution, which might bear a risk of the development of cellular immune deficiency symptoms.