CD4(-)/CD8(-) variant of T-cell large granular lymphocytic leukemia or hepatosplenic T-cell lymphoma: a clinicopathologic dilemma

[Forensic pathological diagnostics of rare T-cell leukemia in re-examination]

A forensic pathological case of rare T-cell leukemia is reported. Autopsy samples (paraffine blocks and slides) from 32 years old female with long-term existing anemia and leukopenia, number of chronic inflammatory diseases, died from fulminant pneumonia, were presented for forensic pathological re-examination. A routine histological examination was done using standard H&E stain. Additionally, we used IHC stain with antibodies to CD3 and CD20 when examining bone marrow and liver samples. The T-cell infiltration in bone marrow (interstitial and intrasinusoidal type) were found. The next step was IHC bone marrow examination with CD4, CD5, CD8, CD56 antibodies. We concluded that the patient had unrecognized T-cell leukemia, based on anamnestical, clinical data and results of our histological and IHC examination. In this case, the T-cell leukemia was not found neither vitally nor at primary forensic pathological examination after autopsy. The necessity of minimal IHC stain sets usage in primary forensic pathology units and IHC's decisive role in bone marrow pathological examination are discussed.

Defining TCRγδ lymphoproliferative disorders by combined immunophenotypic and molecular evaluation

Tγδ large granular lymphocyte leukemia (Tγδ LGLL) is a rare lymphoproliferative disease, scantily described in literature. A deep-analysis, in an initial cohort of 9 Tγδ LGLL compared to 23 healthy controls, shows that Tγδ LGLL dominant clonotypes are mainly public and exhibit different V-(D)-J γ/δ usage between patients with symptomatic and indolent Tγδ neoplasm. Moreover, some clonotypes share the same rearranged sequence. Data obtained in an enlarged cohort (n = 36) indicate the importance of a combined evaluation of immunophenotype and STAT mutational profile for the correct management of patients with Tγδ cell expansions. In fact, we observe an association between Vδ2/Vγ9 clonality and indolent course, while Vδ2/Vγ9 negativity correlates with symptomatic disease. Moreover, the 7 patients with STAT3 mutations have neutropenia and a CD56-/Vδ2- phenotype, and the 3 cases with STAT5B mutations display an asymptomatic clinical course and CD56/Vδ2 expression. All these data indicate that biological characterization is needed for Tγδ-cell neoplasm definition.

Tγδ large granular lymphocyte leukemia (Tγδ LGLL) is a rare lymphoproliferative neoplasm characterized by the expansion of T large granular lymphocytes expressing γδ TCR. Here, based on deep sequencing analysis of the clonotype repertoire, the authors show that leukemic Tγδ cells are characterized by recurrent public clonotypes that are diversified between symptomatic and asymptomatic patients.

Hepatosplenic γ-δ T-Cell Lymphoma: Who Is on Your Speed Dial?

Hepatosplenic γ-δ T-cell lymphoma, an exceptionally uncommon subtype of peripheral T-cell lymphomas, commonly presents with advanced-stage disease manifesting with hepatosplenomegaly, cytopenias, and constitutional symptoms. Management of this subset is challenging as a result of the unique presentation and refractory nature to conventional treatment approaches. There is a lack of consensus guidelines for up-front induction strategies, and the role of consolidative autologous or allogeneic stem-cell transplantation is controversial. Prospective studies are lacking, and treatment is often guided by literature on the basis of case series or single-institution studies, lending to expert opinions influencing treatment paradigms.

T-Cell Large Granular Lymphocytic Leukemia with Extremely Rare Immunophenotype (CD4/CD8 Double-Positive) Followed by Multiple Myeloma Diagnosis

T-cell large granular lymphocytic leukemia is characterized by clonal expansion of a CD3⁺/CD57⁺ subpopulation, which are typically CD8⁺ positive cytotoxic T- cells, and can only be diagnosed if there is a persistent, greater than 6 months, elevation of LGL in the blood (usually 2–20 × 10⁹/L), in the absence of an identifiable cause. T-LGLL has been associated with reactive conditions such as autoimmune diseases and viral infections and has also been reported in association with hematologic and non-hematologic malignancies. We report a case of asymptomatic CD4/CD8 double-positive T-LGLL. Flow cytometry on peripheral blood revealed a subpopulation of CD4/CD8 double-positive T cells expressing CD57 and cTIA. Clonality was established by flow cytometric analysis of T-cell receptor V(â) region repertoire which showed that >70% of the cells failed to express any of the tested V(â) regions. Clonality was further confirmed by PCR with the detection of clonal TCR beta and TCR gamma gene rearrangements. Six months later, she presented with persistent lower back pain and diagnosed with IgG kappa multiple myeloma. CD4/CD8 double-positive T-large granular leukemia is the first case reported in the literature. This rare phenotype is either underreported or a truly rare clinical entity. More studies are warranted to characterize the pathogenesis and clinical characteristics of this group of patients and to further assess the relationship between multiple myeloma and T-LGLL as a cause-and-effect relationship or simply related to the time at which diagnosis has been made.

Causes of double-negative T-cell lymphocytosis in children and adults

AIMS

The causes and diagnosis of 'double-negative' (CD3+CD4-CD8-) T-cell lymphocytosis are not well studied. We aimed to define the causes of double-negative T-cell lymphocytosis in children and adults, and to identify simple clinical and laboratory features that would help to differentiate between the underlying conditions.

METHODS

We collected clinical and laboratory data on 10 children and 30 adults with significantly increased peripheral-blood double-negative T-cells (>10% of total lymphocytes). We identified conditions associated with double-negative T-lymphocytosis with flow cytometry, peripheral-blood morphology and T-cell receptor-gene rearrangement studies. Patients were assigned to diagnostic categories on the basis of these test results.

RESULTS AND CONCLUSIONS

The causes of double-negative T-cell lymphocytosis in children were autoimmune lymphoproliferative syndrome (ALPS) and reactive γ/δ Τ-lymphocytosis. T-cell large granular lymphocyte (T-LGL) leukaemia, reactive γ/δ T-lymphocytosis and hepatosplenic T-cell lymphoma (HSTL) were the the most common disorders underlying double-negative T-cell lymphocytosis in adults. Less common causes included hypereosinophilic syndrome, peripheral T-cell lymphoma, ALPS and monoclonal, double-negative T-lymphocytosis of uncertain significance. CD5/CD7/Vδ2 expression and absolute double-negative lymphocyte count (<1.8×10⁹/L) were useful discriminators for distinguishing patients with reactive γ/δ T-lymphocytosis from those with γ/δ lymphoproliferative disorders. Differentiating between γ/δ T-LGL and HSTL can be difficult. Expression of CD57 and cellular morphology (pale cytoplasm with distinct granules) would support a diagnosis of γ/δ T-LGL.

Hepatosplenic T-cell lymphoma in a young immunocompetent man

Hepatosplenic T-cell lymphoma (HSTCL) is a rare, aggressive type of peripheral T-cell lymphoma that is characterised by extranodal disease, with infiltration and proliferation of malignant T-cells within the liver, spleen and bone marrow. The authors report the case of a young immunocompetent man, who was admitted to the hospital with a history of prolonged, unexplained fever, fatigue and weight loss. Initial blood work showed mild pancytopaenia and imaging studies revealed hepatosplenomegaly. The diagnosis was challenging, initially mimicking infectious disease, and it required an extensive investigation that ultimately revealed the characteristic clinical, histopathological and cytogenetic features of HSTCL. The clinical course was aggressive, and despite multiagent chemotherapy, the patient died 4 months after the diagnosis. This case highlights the difficulty of diagnosing HSTCL and the importance of considering it in a differential diagnosis of hepatosplenomegaly in young men who present with constitutional symptoms and no lymphadenopathy.

Hepatosplenic T-Cell Lymphoma: A Clinicopathologic Review With an Emphasis on Diagnostic Differentiation From Other T-Cell/Natural Killer-Cell Neoplasms

Hepatosplenic T-cell lymphoma is a rare, aggressive T-cell lymphoma, characterized by hepatosplenic sinusoidal infiltration of monotonous, medium-sized, nonactivated cytotoxic T cells, usually of γ/δ T-cell receptor type. Hepatosplenic T-cell lymphoma occurs more frequently in immunocompromised patients, especially in those receiving long-term immunosuppressive therapy. Patients usually manifest hepatosplenomegaly without lymphadenopathy. The bone marrow is also involved in two-thirds of cases and is often accompanied by circulating lymphoma cells, which, along with anemia and thrombocytopenia, may raise suspicion for acute leukemia. The differential diagnosis includes aggressive natural killer-cell leukemia, T-large granular lymphocytic leukemia, T-lymphoblastic leukemia, enteropathy-associated T-cell lymphoma type II, primary cutaneous γ/δ T-cell lymphoma, other peripheral T-cell lymphomas, myelodysplastic syndrome, and infectious mononucleosis. The diagnosis is usually established from the combination of clinical findings, histologic features, and immunophenotype, although cytogenetic/molecular studies are occasionally needed. Hepatosplenic T-cell lymphoma exhibits a dismal clinical course with a poor response to currently available therapies.