Methotrexate-associated lymphoproliferative disorders of T-cell phenotype: clinicopathological analysis of 28 cases

Development of Diffuse Large B Cell Lymphoma in a Patient with Systemic Lupus Erythematosus within Two Years after the Initiation of Anifrolumab and Mycophenolate Mofetil Treatment

Anifrolumab is a newly developed biological agent for patients with moderate-to-severe systemic lupus erythematosus (SLE). Anifrolumab neutralizes the signaling pathways mediated by type I interferons (IFNs), which are involved in viral clearance and anticancer immunity. Although susceptibility to viral infections has been reported in patients treated with anifrolumab, whether anifrolumab treatment increases the cancer risk in patients with SLE is unknown. We herin report a case of SLE that manifested as aggressive diffuse large B-cell lymphoma (DLBCL) after treatment with anifrolumab. The neutralization of type I IFNs by anifrolumab may promote the development of DLBCL owing to defective anticancer immunity.

Angioimmunoblastic T-cell lymphoma: Current Diagnostic Insights and Advances

Angioimmunoblastic T-cell lymphoma (AITL), or nodal T-follicular helper cell lymphoma, angioimmunoblastic type, is a rare and aggressive type of T-cell lymphoma characterized by a spectrum of clinical and histopathological features that can present diagnostic challenges. Derived from T-follicular helper cells, the genesis of AITL is thought to be a multistep process involving mutations in epigenetic regulatory genes such as TET2 and DNMT3A, followed by driver mutations in RHOAG17V and IDH2R172 which promote clonal expansion as well as a characteristic inflammatory milieu. This review aims to provide a comprehensive overview of AITL, including its clinical presentation, epidemiology, pathogenesis, histomorphology and treatment options. Despite advancements in the understanding of AITL biology and the development of novel treatment strategies, the prognosis for patients with AITL remains poor.

Primary Cutaneous Methotrexate-Associated T-Cell Lymphoproliferative Disorder in the Setting of Autoimmune Disease: A Case Series and Review of the Literature

ABSTRACT

Methotrexate (MTX), an antimetabolite targeting certain autoimmune conditions and various hematologic malignancies, has been associated with iatrogenic lymphoproliferative disease (LPD) primarily of B-cell lineage. Less commonly are T-cell neoplasms where primary skin involvement is considered rare. Three cases were encountered in the medical practice of one of the authors. The patients ranged in age from 38 years to 99 years (2 women and 1 man) with 2 having rheumatoid arthritis and 1 having ankylosing spondylitis. All 3 patients received MTX. The cases included subcutaneous peripheral T-cell lymphoma not otherwise specified (NOS) (1 patient), mycosis fungoides (1 patient), and a primary aggressive epidermotropic cytotoxic T-cell lymphoma (1 patient) that proved to be fatal. One patient had spontaneous regression following MTX withdrawal; she later developed a recurrence while off MTX. Two patients died, 1 of unrelated causes and 1 of lymphoma. Seven previously reported cases included subcutaneous panniculitis-like T-cell lymphoma (2 cases), primary cutaneous CD4+ LPD (2 cases), peripheral T-cell lymphoma (NOS) (1 case), anaplastic large cell lymphoma (1 case), and peripheral T-cell lymphoma localized to fat (1 case). Regression without recurrence occurred in 6 of the 7 patients with MTX withdrawal. The patients were on the MTX for an average of 4 years and had a median age of 61 years with a slight dominance of men over women. Three of the 7 cases showed Epstein-Barr encoding region (EBER) positivity while the 3 cases reported in this series were negative. MTX-associated T-cell LPD involves older patients on long-term MTX where EBER positivity is more frequent than extracutaneous MTX-associated T-cell LPD. A spectrum of classic forms of CTCL is seen with subcutaneous involvement representing a significant percentage of cases. Regression with MTX withdrawal occurs although not in every case.

Analysis of Notch1 protein expression in methotrexate-associated lymphoproliferative disorders

Methotrexate (MTX)-associated lymphoproliferative disorder (MTX-LPD) is a lymphoproliferative disorder in patients treated with MTX. The mechanism of pathogenesis is still elusive, but it is thought to be a complex interplay of factors, such as underlying autoimmune disease activity, MTX use, Epstein-Barr virus infection, and aging. The NOTCH genes encode receptors for a signaling pathway that regulates various fundamental cellular processes, such as proliferation and differentiation during embryonic development. Mutations of NOTCH1 have been reported in B-cell tumors, including chronic lymphocytic leukemia/lymphoma, mantle cell lymphoma, and diffuse large B-cell lymphoma (DLBCL). Recently, it has also been reported that NOTCH1 mutations are found in post-transplant lymphoproliferative disorders, and in CD20-positive cells in angioimmunoblastic T-cell lymphoma, which might be associated with lymphomagenesis in immunodeficiency. In this study, to investigate the association of NOTCH1 in the pathogenesis of MTX-LPD, we evaluated protein expression of Notch1 in nuclei immunohistochemically in MTX-LPD cases [histologically DLBCL-type (n = 24) and classical Hodgkin lymphoma (CHL)-type (n = 24)] and de novo lymphoma cases [DLBCL (n = 19) and CHL (n = 15)]. The results showed that among MTX-LPD cases, the expression of Notch1 protein was significantly higher in the DLBCL type than in the CHL type (P < 0.001). In addition, among DLBCL morphology cases, expression of Notch1 tended to be higher in MTX-LPD than in the de novo group; however this difference was not significant (P = 0.0605). The results showed that NOTCH1 may be involved in the proliferation and tumorigenesis of B cells under the use of MTX. Further research, including genetic studies, is necessary.

Multiple Ulcers in the Ileum and Lymphadenopathy Following the Usage of Methotrexate in a Patient With Rheumatoid Arthritis: A Case Report

This case report aims to highlight a rare occurrence of severe anemia and lymphadenopathy secondary to methotrexate (MTX)-induced ileal mucosa damage in a patient with elderly onset rheumatoid arthritis (EORA). We present the case of a 72-year-old female with a history of EORA, treated with MTX, who exhibited hematochezia without accompanying pain, diarrhea, or known infectious contacts. Diagnostic investigations included imaging and endoscopic procedures. The patient's presentation of severe anemia was atypical, given the absence of significant pain or discomfort associated with EORA. The lack of active bleeding observed during endoscopy, coupled with multiple ileal ulcers, suggested a chronic progression of mucosal damage. Laboratory findings, including normal lactate dehydrogenase, soluble interleukin-2 receptor levels, and the absence of malignancy in mucosal biopsies, ruled out MTX-induced lymphoma. The patient's condition improved with the cessation of MTX and the introduction of symptomatic treatment and anemia management. This case underscores the need for vigilant monitoring and comprehensive evaluation in patients with RA, especially the elderly, treated with MTX. It also highlights the importance of considering drug-induced complications in the differential diagnosis of anemia. The case demonstrates the necessity of a personalized approach to treatment, emphasizing regular follow-ups and adjustments based on the patient's response to therapy. This report contributes to the growing body of evidence on the complexities of managing RA in the elderly, particularly regarding the side effects of common medications like MTX.

Sigmoid Colon Perforation in Diffuse Large B-Cell Lymphoma Due to Tacrolimus-Induced Immunodeficiency: A Case Report

The sigmoid colon is an uncommon site for the origin of primary malignant lymphomas in the GI tract. Additionally, immunosuppressive agents, widely used in treating autoimmune diseases, have been associated with the induction of malignancies, including lymphoproliferative disorders. In this report, we present a rare case of GI perforation suggesting a link between immunosuppressive therapy, particularly tacrolimus treatment, and diffuse large B-cell lymphoma (DLBCL). A 75-year-old female patient presented with abdominal pain to our ER. She had a medical history of polymyositis and interstitial pneumonia, treated with the immunosuppressant tacrolimus. An abdominal CT scan revealed free gas in the abdominal cavity, leading to a diagnosis of GI perforation. The patient exhibited generalized peritonitis and underwent emergency surgery the same day. During surgery, a perforation in the sigmoid colon was identified, and a Hartmann procedure was performed. Postoperative pathology showed CD20+, CD30+, CD5-, CD10-, BCL6+, MUM1+, and MIB-1 LI of 50-60%. The diagnosis of DLBCL was confirmed, classified as EBV-positive diffuse large B-cell lymphoma, not otherwise specified (NOS), in the sigmoid colon, with positive EBER-ISH, LMP-1, and EBNA2 findings. Given her history of immunosuppressant use, she was categorized as having other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPD), according to the WHO Classification of 2017. This case highlights the importance for clinicians to consider the risk of oncogenesis associated with the prolonged use of immunosuppressive agents.

Clinicopathological findings, prognosis, and Epstein-Barr virus infection in rheumatoid arthritis patients with other iatrogenic immunodeficiency-associated T- and NK-cell lymphoproliferative disorders

BACKGROUND

Other iatrogenic immunodeficiency-associated (OIIA) T- and natural killer (NK)-cell lymphoproliferative disorders (TNK-LPDs) are rare in patients with rheumatoid arthritis (RA).

METHODS

We investigated the clinicopathological characteristics, Epstein-Barr virus (EBV) infection, genetic findings, therapeutic response, and prognostic factors in 21 RA patients with OIIA TNK-LPDs and compared these with those of 39 with OIIA B-cell LPDs (B-LPDs) and 22 with non-OIIA B-LPDs.

RESULTS

Immunohistologically, 11 patients (52%) showed CD4+ T-LPDs, and 7 had a T follicular helper (TFH) phenotype. The other nine patients (43%) showed CD8+ T-LPDs, and the remaining one (5%) had features of CD3+ CD4- CD8- nasal type TNK-cell lymphoma. CD30+, p53+, and CMYC+ atypical lymphocytes were identified in seven (33%), eight (38%), and five (24%) patients, respectively. In situ hybridisation detected EBV-encoded RNA (EBER) + large atypical lymphocytes in five patients (24%). Nine of 17 patients (53%) showed clonal peaks of TCRγ by polymerase chain reaction. Withdrawal of MTX and biologic drugs was effective in 12 patients (57%), and 8 (38%) received chemotherapies. Two patients with TFH+ or EBV+ CD4+ CD30+ large cell peripheral T-cell lymphoma, one with CD8+ systemic anaplastic large cell lymphoma, and two with systemic EBV+ CD8+ T-cell lymphoma of childhood showed a lethal progressive clinical course within 13 months. Moreover, > 500 U/L LDH, large atypical lymphocytes, expression of CD30, p53, and CMYC, and EBER+ atypical lymphocytes were significantly poor prognostic factors for overall survival (p < 0.05). Median interval from RA onset to OIIA TNK-LPDs was 72 months, which was shorter than 166 months in OIIA B-LPDs (p = 0.003). EBV+ atypical and reactive lymphocytes were frequently found in 15 patients with OIIA TNK-LPDs (71%), in 27 with OIIA B-LPDs (69%), and only in 3 with non-OIIA B-LPDs (14%).

CONCLUSIONS

OIIA TNK-LPDs occurred in early phase of RA, compared with OIIA B-LPDs, and occasionally showed a lethal progressive clinical course. Detection of OIIA TNK-LPD patients with poor prognostic factors is necessary. EBV infection in immunosuppressed patients due to persistent RA, MTX, and biologic drugs may play a role in forming the tumour microenvironment and lymphomagenesis of TNK-LPDs.

Angioimmunoblastic T-cell Lymphoma Presenting as a Methotrexate-associated Lymphoproliferative Disorder with Extreme Peripheral Blood Plasmacytosis

A 74-year-old man was admitted to our hospital because of systemic lymphadenopathy, weight loss, and a fever at night that had persisted for approximately 1 month. Blood tests revealed extreme peripheral blood plasmacytosis and hypergammaglobulinemia. A lymph node biopsy showed angioimmunoblastic T-cell lymphoma (AITL). Based on the history of methotrexate (MTX) administration, the established diagnosis was MTX-associated lymphoproliferative disorder (MTX-LPD). After MTX was discontinued, the lymphadenopathy spontaneously regressed and the plasmacytosis disappeared. He had no disease progression for three years. We found that AITL as an MTX-LPD can cause plasmacytosis, and the prognosis of this disease may not be poor.

Primary Central Nervous System T-cell Lymphoma as Methotrexate-associated Lymphoproliferative Disorders: Case Report

We report a rare case of primary central nervous system (CNS) lymphoma as methotrexate-associated lymphoproliferative disorders (MTX-LPD). A 75-year-old woman who had been treated for rheumatoid arthritis (RA) with MTX for 3 years was admitted to our hospital complaining of unsteady gait, nausea, and vomiting. T2-weighted image of magnetic resonance imaging (MRI) showed multiple high intensity mass-like lesions including right lateral, frontal and temporal lobes, and right cerebellar hemisphere. We performed surgical biopsy, and the pathological and immunohistochemical examinations identified T-cell lymphoma. The tumor regressed and the symptoms were resolved soon after MTX withdrawal. Primary CNS lymphoma due to MTX-LPD is a rare disease and only eight cases including ours are reported.

The first case of methotrexate-associated lymphoproliferative disorder presenting as follicular T-cell lymphoma

This is the first case of follicular T-cell lymphoma (FTCL) presenting as methotrexate-associated lymphoproliferative disorders (MTX-LPDs). A 69-year-old man treated rheumatoid arthritis with methotrexate presented with cervical swelling, hoarseness and fever. Imaging studies revealed multiple lymphadenopathy and lymphoma was suspected. Lymph node biopsy was performed to confirm the diagnosis. Pathologically, the lymph node was composed of atypical lymphocytes with a follicular growth pattern and area of necrosis. Immunohistochemical examination showed the atypical lymphocytes were positive for CD3, CD4, programmed cell death protein 1, and inducible T-cell co-stimulator. These findings are consistent with FTCL. During hospitalization, the patient's fever subsided and cervical lymphadenopathy improved, probably due to discontinuation of MTX. Here we presented the first case of FTCL presenting as MTX-LPDs. The T-cell phenotype MTX-LPDs are relatively rare and accounts for only 3.4%-6.3% of all MTX-LPD cases. Therefore, detailed clinicopathological features have not been clarified sufficiently. It is hoped that similar cases should be accumulated and studied to better understand the clinical and pathological features of this condition.

EBV-positive B-cell lymphomas and lymphoproliferative disorders: Review from the perspective of immune escape and immunodeficiency

Background

Epstein‐Barr virus (EBV) is detected in a variety of B‐cell lymphomas (BCLs) and B‐cell lymphoproliferative disorders (B‐LPDs). Immunodeficiency has been considered to play a key role in the pathogenesis of these diseases. In addition, immune escape of tumor cells may also contribute to the development of EBV⁺ BCLs and B‐LPDs. The PD‐1/PD‐L1 pathway is particularly important for immune escape of tumor cells that contribute to development of lymphoma through suppression of cytotoxic T‐cell function. We now consider PD‐L1 immunohistochemistry (IHC) a very useful method for predicting whether tumor cells of lymphoid malignancies are characterized by the immune escape mechanism.

Methods

We reviewed articles of EBV⁺ BCLs and B‐LPDs from the perspective of immune escape and immunodeficiency, particularly focusing on PD‐L1 IHC.

Results

Based on PD‐L1 IHC, we consider that EBV⁺ BCL and B‐LPD can be classified into three types: “immunodeficiency”, “immune escape”, and “immunodeficiency + immune escape” type. The immunodeficiency type includes EBV⁺ diffuse large BCL (DLBCL) of the elderly, EBV⁺ sporadic Burkitt lymphoma, EBV⁺ mucocutaneous ulcer, and methotrexate (MTX)‐associated B‐LPD. The immune escape type includes EBV⁺ classic Hodgkin lymphoma (CHL) and EBV⁺ DLBCL of the young. The immunodeficiency + immune escape type includes CHL type MTX‐associated LPD and a minor subset of EBV⁺ DLBCL of the elderly.

Conclusions

Recently, good results have been reported for immune check‐point inhibitors in treating lymphoma. Lymphomas and LPDs characterized by immune escape are regarded as good candidates for PD1/PD‐L1 blockade therapy. Therefore, from both the clinical and pathological perspective, we suggest that lymphoma diagnosis should be made considering immune escape and immunodeficiency.

Virus-Driven Carcinogenesis

Cancer arises from the accumulation of genetic and epigenetic alterations. Even in the era of precision oncology, carcinogens contributing to neoplastic process are still an important focus of research. Comprehensive genomic analyses have revealed various combinations of base substitutions, referred to as the mutational signatures, in cancer. Each mutational signature is believed to arise from specific DNA damage and repair processes, including carcinogens. However, as a type of carcinogen, tumor viruses increase the cancer risk by alternative mechanisms, including insertional mutagenesis, viral oncogenes, and immunosuppression. In this review, we summarize virus-driven carcinogenesis to provide a framework for the control of malignant cell proliferation. We first provide a brief overview of oncogenic viruses and describe their implication in virus-related tumors. Next, we describe tumor viruses (HPV, Human papilloma virus; HBV, Hepatitis B virus; HCV, Hepatitis C virus; EBV, Epstein-Barr virus; Kaposi sarcoma herpesvirus; MCV, Merkel cell polyoma virus; HTLV-1, Human T-cell lymphotropic virus, type-1) and tumor virus-related cancers. Lastly, we introduce emerging tumor virus candidates, human cytomegalovirus (CMV), human herpesvirus-6 (HHV-6) and adeno-associated virus-2 (AAV-2). We expect this review to be a hub in a complex network of data for virus-associated carcinogenesis.

Outcomes of methotrexate-associated lymphoproliferative disorders in rheumatoid arthritis patients treated with disease-modifying anti-rheumatic drugs

Recently, the use of targeted synthetic or biological disease-modifying anti-rheumatic drugs (ts/bDMARDs) in addition to conventional synthetic (cs)DMARDs including methotrexate (MTX) for rheumatoid arthritis (RA) has increased. However, whether ts/bDMARDs are associated with the development and clinicopathological features of MTX-associated lymphoproliferative disorder (MTX-LPD) in patients with RA remains unknown. Therefore, we evaluated the clinical outcomes of 121 patients with MTX-LPD. Results showed that prior use of ts/bDMARDs was not associated with the different histopathological subtypes of MTX-LPD. Patients with polymorphic-type LPD had a better event-free survival than those with diffuse large B-cell lymphoma (DLBCL), classical Hodgkin lymphoma and peripheral T-cell lymphoma. The pathological subtype of lymphoma could predict the clinical outcome of MTX-LPD. In patients with DLBCL, the use of tumour necrosis factor-alpha (TNF-α) inhibitors prior to MTX-LPD onset was associated with a higher non-relapse mortality. Further, patients with RA previously treated with Janus kinase (JAK) inhibitors more commonly required chemotherapy than those treated with csDMARDs alone, indicating disease aggressiveness. Hence, special caution should be observed when managing patients with MTX-LPD previously treated with JAK or TNF-α inhibitors for RA.

Primary cutaneous methotrexate-associated B-cell lymphoproliferative disorders other than EBV-positive mucocutaneous ulcer: clinical, pathological, and immunophenotypic features

Methotrexate (MTX)-associated B-cell lymphoproliferative disorders (B-LPD) may first present in the skin. Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) is now a well known disease listed in the 2017 World Health Organization classification. However, primary cutaneous MTX-associated B-LPD (pcMTX B-LPD), other than EBVMCU, appear to be underestimated, and their distinctiveness remains unproven. This study aimed to document the clinicopathological characteristics of nine patients with pcMTX B-LPD that were not EBVMCU to extend our understanding of this peculiar disease. The cohort included three males and six females, with a median age of 74 years (range 54-83 years). All patients were treated with MTX for RA. Of nine patients, four presented with a solitary lesion, and five had multiple lesions. Histologically, five cases showed a polymorphic pattern, and four showed a monomorphic pattern. Immunohistochemically, four cases showed positive EBER staining, and one showed positive CD5 staining. In eight cases, once pcMTX B-LPD was diagnosed, methotrexate was immediately withdrawn. All eight of these patients experienced spontaneous regression and achieved complete remission (CR), without relapse. The patient with CD5 positivity received cytotoxic chemotherapy as the initial treatment. This patient achieved a CR after the initial treatment, but eventually experienced disease relapse resulting in death. We also revealed that pcMTX B-LPD and MTX-associated EBVMCU exhibited similar biological behaviours. We concluded that most pcMTX B-LPD cases could be cured by stopping MTX treatment. We also highlighted the fact that pcMTX B-LPD and MTX-EBVMCU had overlapping features. This finding suggested that pcMTX B-LPD and MTX-EBVMCU might share an underlying mechanism.

Case Report: Composite Angioimmunoblastic T-Cell Lymphoma and Epstein-Barr Virus-Positive B-Cell Lymphoproliferative Disorder as Other Iatrogenic Immunodeficiency-Associated Lymphoproliferative Disorders

Immunosuppressants are widely used to treat patients with rheumatoid arthritis (RA), and their adverse effects have been known to cause other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPDs). We report a patient with RA who had been treated with methotrexate (MTX) and tacrolimus (TAC) and who developed whole body lymphadenopathy. We simultaneously confirmed angioimmunoblastic T-cell lymphoma (AITL) through a right cervical lymph node biopsy and Epstein-Barr virus-positive B-cell lymphoproliferative disorder (EBV-positive B-LPD) through a bone marrow examination. After cessation of immunosuppressant therapy, both LPDs completely disappeared. Patients with AITL are occasionally reported to develop B-cell lymphoma through reactivation of the EBV, which leads to clonal expansion in the microenvironment. Immunohistochemistry results revealed that both LPD components were positive for EBV-encoded RNA. Moreover, in this patient, the plasma EBV DNA level was found to be high; therefore, EBV infection was a probable etiology. Synchronous coexistence of AITL and B-LPD as an OIIA-LPD has rarely been reported. This case report is the first to discuss the disappearance of both LPDs on withdrawal of immunosuppressants only. AITL occasionally accompany B-LPD; however, this composite lymphoma comprised AITL and B-LPD, and OIIA-LPDs should not be overlooked.

Nodal EBV-positive polymorphic B cell lymphoproliferative disorder with plasma cell differentiation: clinicopathological analysis of five cases

Plasma cell differentiation (PCD) is frequently observed in some entities of non-Hodgkin B cell lymphoma, including both low-grade and high-grade lymphomas. However, except for plasmablastic lymphoma and primary effusion lymphoma, EBV⁺ B cell lymphoproliferative disorder (LPD) with PCD has not been well addressed due to its rarity. We clinicopathologically examined five cases of nodal EBV⁺ polymorphic B cell LPD with PCD (PBLPD-PCD) initially diagnosed as polymorphic EBV⁺ diffuse large B cell lymphoma, not otherwise specified (DLBCL-NOS) with PCD (n = 3) and methotrexate-associated B cell LPD (MTX-associated B-LPD) (n = 2). One case had a concomitant brain lesion which was clinically diagnosed as EBV-related encephalitis. This patient received therapy with vidarabine, and both the brain lesion and the nodal EBV⁺ PBLPD-PCD lesions disappeared. Another case was characterized by Mott cell differentiation. This case was the first reported case of EBV⁺ B cell lymphoma or LPD with Mott cell differentiation. The two cases of MTX-associated B cell LPD which arose in patients with rheumatoid arthritis spontaneously regressed after MTX cessation. TCRγ and IGH PCR analysis was performed in four cases. Two cases had TCRγ rearrangements, but no IGH rearrangements. The other two cases had no rearrangements in these genes. We concluded that nodal EBV⁺ PBLPD-PCD is rare, with heterogeneous characteristics. PCR analysis revealed that nodal EBV⁺ PBLPD-PCD may have only TCR clonality and no IGH clonality. Considering the partial or complete loss of CD20 expression on the tumor cells, this result may be confusing for accurate diagnosis of EBV⁺ PBLPD-PCD, and pathologists need to be aware of this phenomenon to avoid misdiagnosis.

A case of bilateral methotrexate-associated diffuse large B-cell lymphomas of the breasts with unique clinical presentation and outcome

A 54-year-old woman on methotrexate (MTX) treatment developed reddish skin change in her right breast. Mammography and ultrasound showed no masses in the breasts but bilateral mammary glands presented diffuse lower-level echoes. Only 19 days later, the patient developed bilateral breast masses. Histological examination showed that diffuse large B-cell lymphoma cells spread widely and sparsely in the bilateral breasts in addition to the tumor cell conglomerate, leading to the diagnosis of MTX-associated lympho-proliferative disorders (MTX-LPDs). Withdrawal of MTX resulted in complete disappearance of the left MTX-LPD in 2 months but no regression of the right MTX-LPD. Chemotherapy led to a partial response followed by re-growth of the right MTX-LPD. Re-biopsy of the right MTX-LPD revealed double/triple hit lymphoma. Second-line and later-line chemotherapies caused no regression of the right MTX-LPD. The patient died in a year after the diagnosis of MTX-LPDs. Breast oncologists should note the presence, biology, and diagnostic images of MTX-LPD.

PD-L1 expression on tumor or stromal cells of nodal cytotoxic T-cell lymphoma: A clinicopathological study of 50 cases

Inhibitors of programmed cell-death 1 (PD-1) and programmed cell-death ligand 1 (PD-L1) have revolutionized cancer therapy. Nodal cytotoxic T-cell lymphoma (CTL) is characterized by a poorer prognosis compared to nodal non-CTLs. Here we investigated PD-L1 expression in 50 nodal CTL patients, with and without EBV association (25 of each). We identified seven patients (14%) with neoplastic PD-L1 (nPD-L1) expression on tumor cells, including three males and four females, with a median age of 66 years. One of the seven cases was TCRαβ type, three were TCRγδ type and three were TCR-silent type. Six of the seven cases exhibited a lethal clinical course despite multi-agent chemotherapy, of whom four patients died within one year of diagnosis. Morphological findings were uniform, with six cases showing centroblastoid appearance. Among nPD-L1+ cases, two of three examined had structural variations of PD-L1 disrupting 3'-UTR region. Notably, all of the TCRγδ-type nodal CTL cases showed nPD-L1 or miPD-L1 positivity (3 and 10 cases, respectively). TCRγδ-type cases comprised 42% of nPD-L1+ cases (P = 0.043 vs. PD-L1- ), and 35% of miPD-L1+ cases (P = 0.037 vs. PD-L1- ). The results indicate that PD-L1+ nodal CTL cases, especially of the TCRγδ type, are potential candidates for anti-PD-1/PD-L1 therapies.

Other Iatrogenic Immunodeficiency-Associated Lymphoproliferative Disorders with a T- or NK-cell phenotype

Other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPDs) with a T- or NK-cell phenotype are markedly rare, with only a limited number of cases having been reported thus far. Methotrexate (MTX) is the most common agent used for OIIA-LPD patients, and 43 cases of MTX-associated T-LPDs (MTX T-LPDs) and five cases of MTX-associated NK/T-LPDs (MTX NK-LPDs) have been described. In addition to MTX T-LPDs and MTX NK/T-LPDs, T-LPD and NK/T-LPDs have been reported in patients receiving other immunosuppressive agents such as thiopurines, TNF antagonists, and cyclosporine. Hepatosplenic T-cell lymphoma (HSTL) is specifically associated with iatrogenic immunodeficiency, and 10% of HSTL cases develop in patients receiving thiopurines and/or TNF antagonists for inflammatory bowel disease (IBD). In this review, we focused on MTX T-LPD, MTX NK/T-LPD, and HSTL in patients with IBD. These T- and NK/T-cell associated OIIA-LPDs are the most common in daily medical practice.