BACKGROUND: The patient was a 65-year-old White woman who presented to dermatology with a painless, rapidly growing exophytic nodule on her left upper cheek.
OBJECTIVE: In this case report, we aim to demonstrate the difficulty of diagnosing Epstein-Barr virus-negative extranodal NK cell lymphomas given the broad differential of NK cell lymphomas and the rarity of EBV-negative extranodal NK cell lymphoma.
METHODS: Immunohistochemical studies confirmed the diagnosis of cutaneous, extranodal NK cell lymphoma. Interestingly, Epstein-Barr virus in situ hybridization was negative, which is unusual for most NK cell lymphomas.
CONCLUSIONS: In our view, a combination of immunohistochemistry, clonality assessment, sequencing, and flow cytometric studies is required.

Extranodal NK/T-cell lymphoma (ENKTL) generally expresses cytotoxic molecules, including granzyme B (GZMB), T-cell-restricted intracellular antigen-1 (TIA-1), and perforin; however, the expression of these molecules varies across cases. We performed gene expression profiling and identified unique biological and clinicopathological features of GZMB-negative ENKTL. We reviewed the clinicopathological characteristics of 71 ENKTL samples. Gene expression profiling on nine ENKTLs using multiplexed, direct, and digital mRNA quantification divided ENKTLs into Groups A (n = 7) and B (n = 2) through hierarchical clustering and t-distributed stochastic neighbor embedding. Group B was characterized by downregulation of genes associated with IL6-JAK-STAT3 signaling and inflammatory responses. GZMB mRNA expression was significantly downregulated in Group B. GZMB protein expression was evaluated with immunohistochemistry in all 71 ENKTLs, and expression data of Tyr705-phosphorylated STAT3 (pSTAT3) and MYC from our previous study was utilized. T-cell receptor gamma (TRG) gene rearrangement in the selected samples was also assessed using PCR. GZMB expression was higher in pSTAT3-positive (p = 0.028) and MYC-positive (p = 0.014) ENKTLs. Eighteen percent (13/71) of all ENKTLs were negative for GZMB (defined by positivity <10 %); patients with GZMB-negative ENKTLs were often in a higher clinical stage (p = 0.016). We observed no other correlations with clinical parameters or TRG rearrangement and no significant association between GZMB expression and survival. In conclusion, GZMB expression is highly heterogeneous in ENKTLs and is associated with the activation of the JAK-STAT3 pathway and higher MYC expression. GZMB-negative ENKTLs correlate with an advanced clinical stage, suggesting the potential utility of GZMB immunohistochemistry as a biomarker of ENKTL.

Extranodal NK/T cell lymphoma, nasal type（ENKTL） is a highly aggressive malignant tumor derived from NK cells. This article reports a case of ENKTL invading the larynx and digestive tract. The clinical clinical manifestations include hoarseness and intranasal masses.
摘要: 结外鼻型NK/T细胞淋巴瘤（extranodal NK/T cell lymphoma，nasal type，ENKTL）是NK细胞起源的高度侵袭性恶性肿瘤，本文报告1例侵及喉及消化道的ENKTL患者，临床表现为声音嘶哑、鼻腔内肿物。.

Primary cutaneous anaplastic large cell lymphoma (PCALCL) is a subtype of non-Hodgkin lymphoma (NHL) that is localized to the skin. Disseminated disease is rare, and visceral organ involvement is even more so. We report a unique case of PCALCL with gastric metastasis. A 75-year-old man with a history of cutaneous left lower extremity PCALCL status post radiation therapy initially presented with abdominal pain and was found to have diffuse celiac axis and retroperitoneal lymphadenopathy. Endoscopy, initially done to biopsy an involved lymph node (LN), demonstrated a friable gastric nodular lesion with telangiectasias. Biopsy of the lesion and LN revealed anaplastic large cell lymphoma, identical in pathology to the known skin lesion. The patient was treated with systemic chemotherapy with a good response. PCALCL has been thought of as a localized malignancy with a good prognosis and low potential for extracutaneous spread. To our knowledge, this is the first instance of metastatic PCALCL involving the stomach.

Epstein-Barr virus (EBV)-associated lymphomas are common in Asia and exhibit a poor prognosis. As EBV antigens LMP1 and LMP2 are often expressed in EBV-associated lymphomas, these lymphomas should be a good target for antigen-specific cytotoxic T lymphocyte (CTL) therapy. However, CTLs continuously exposed to viral or tumor antigens often become exhausted. Antigen-specific CTLs generated from induced pluripotent stem cells are functionally rejuvenated, showing a strong antitumor effect on EBV-associated lymphomas and persistence in vivo. For feasible \"off-the-shelf\" therapy, we generated allogeneic EBV-specific CTLs in the cell processing center and prepared them for actual use in clinical settings.

Extranodal NK/T cell lymphoma, nasal type (ENKL) primarily involves the nasal cavity. Although patients might visit an otorhinolaryngologist with nasal symptoms, such as nasal obstruction and epistaxis, it would be difficult to make a diagnosis correctly. We present a case of ENKL in which the patient had been in remission after initial treatment and relapsed 14 years after treatment. The patient had a worsening of nasal symptoms before the recurrence, but on this occasion, treatment such as sinusitis was successful in alleviating the symptoms. Although recurrence of lymphoma 10 years after treatment is rare, the possibility of recurrence should always be considered in post-malignant lymphoma cases as with any malignant tumor.

A 72-year-old woman was diagnosed with extranodal NK/T cell lymphoma of the right nasal cavity and received sequential radiochemotherapy comprising focal radiotherapy and THP-COP chemotherapy. Showed a complete tumor response to the treatment; however, the tumor recurred in the contralateral right nasal cavity 15 years after the initial treatment. This was judged to be a marginal recurrence in the radiation field. After four cycles of dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) chemotherapy, a second complete response was achieved. It is possible that another recurrence occurs in the future, and if the lesion is localized at the time of recurrence, it may be possible to control the disease again. Careful follow-up is considered necessary.

Patients with extranodal natural killer/T-cell lymphoma (ENKTL), nasal type are benefit from peg-asparaginase, gemcitabine, and methotrexate. Therefore, we conducted a prospective phase II trial using a combination of these drugs as GAD-M regimen in naïve ENKTL patients, simultaneously, explored the combinational mechanism. The GAD-M regimen was administered for 6 cycles sandwiched by radiotherapy for stage I/II and 6 cycles for stage III/IV patients. After 6 cycles, the overall response rate of 36 patients was 91.6%, and the complete remission rate increased to 83.3%. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 74.8% and 77.8%, respectively. The 5-year PFS and OS were 68.3% and 77.8%. No patient suffered from the central nervous system (CNS) relapse. Most patients experienced recoverable liver dysfunction and anemia in this study. The plasma MTX concentration ratio at 12 to 24 hr during the first cycle could be an early predictor of outcomes in ENKTL (PFS, P=0.005; OS, P=0.002). Additionally, we found that high dose MTX (HD-MTX) and gemcitabine had the synergistic effect of ENKTL cell in vitro. Mechanistically, we demonstrated that the combination could lead to obviously apoptosis in ENKTL cell with extremely release of reactive oxygen spices (ROS), which mediated by endoplasmic reticulum stress. In conclusion, the GAD-M regimen could be a new choice to newly diagnosed ENKTL, especially for stage I/II patients. Furthermore, our results showed the synergy effect of HD-MTX with gemcitabine in ENKTL.
BACKGROUND: This trial was registered at www.clinicaltrials.gov as #NCT01991158.

Extranodal NK/T cell lymphoma (ENKL) is a rare subtype of lymphoma that shows a poor clinical outcome. The most common sites are the nasal cavity, nasopharynx, paranasal sinuses, tonsils and larynx. Because of P-glycoprotein expression on ENKL cells, ENKL is resistant to anthracycline-based chemotherapy. L-asparaginase-based chemotherapy with or without radiotherapy shows promising outcomes for advanced ENKL, but has limited efficacy in relapsed/refractory ENKL. immune-checkpoint inhibitors, histone deacetylase inhibitors, and monoclonal antibodies are being investigated. In this review, we summarize the new treatments for ENKL.

BACKGROUND: We present a unique case of primary breast CD20-positive extranodal NK/T cell lymphoma with stomach involvement in a young Chinese female patient.
METHODS: The patient presented with a mass in her right breast that rapidly increased in size over approximately 2 months. Upper gastrointestinal endoscopy showed a giant serpentine ulcer in the stomach. Biopsy was performed, and microscopic inspection revealed that the fibrous tissue was diffusely involved by medium to large abnormal lymphocytes. The cytoplasm was low to moderate. The tumor cells had irregular nuclei and inconspicuous nucleoli. The lymphoid cells were strongly immunoreactive to CD20, CD3, CD4, CD56, TIA-1, EBER, and Ki-67 (90%). Epstein-Barr virus genomes were also found in tumor cells by in situ hybridization. A whole-body positron emission tomography (PET)-CT scan revealed intense FDG uptake in the right breast and greater curvature of the stomach. Monoclonal rearrangements of the T cell receptor (TCR-γ) and immunoglobulin heavy chain (IgH) were identified by genetic analysis. Whole-genome next-generation sequencing was performed, and up to 12 gene mutations, including a frameshift mutation in exon 4 of the BCOR (G97Rfs*87; 44.3%) gene and a base substitution mutation (Q61H 17.6%) in exon 3 of the KRAS gene, were detected. Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed using the database for annotation, visualization, and integrated discovery, which showed that rare primary breast CD20-positive extranodal NK/T cell lymphoma had a unique genetic background compared with diffuse large B cell lymphoma and extranodal NK/T cell lymphoma without CD20 expression. The patient received four cycles of the modified SMILE regimen. The second whole-body PET-CT scan revealed that the right breast mass was significantly smaller than before; additionally, FDG uptake in the stomach wall disappeared.
CONCLUSIONS: Systemic examination, extensive immunohistochemistry, and molecular profiling are essential for an accurate diagnosis. More similar cases are required to clarify the biological pathways and even the potential molecular mechanisms of rare lymphomas, which may help direct further treatment.