Terminal deoxynucleotidyl transferase negative T-cell lymphoblastic lymphoma in aleukemic patient

T-Cell Acute Lymphoblastic Leukemia/Lymphoma (T-ALL) With Negative Screening Immaturity Markers and Gamma-Delta Receptor Expression

T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) is characterized by the combination of T-cell lineage and the presence of immaturity marker(s). Sometimes, the most common immaturity markers for initial flow cytometry screening in T-ALL may be negative, which can be a diagnostic pitfall. When a lack of common first-line immaturity markers is encountered in combination with gamma/delta T-cell receptor expression, a misdiagnosis of mature gamma-delta T-cell leukemia/lymphoma could be rendered. Here, we discuss two T-ALL cases with the absence of common flow cytometry immaturity markers and positive gamma/delta receptor expression.

A New Treatment Strategy for Early T-Cell Precursor Acute Lymphoblastic Leukemia: A Case Report and Literature Review

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is an aggressive and extremely fatal subtype of T-cell acute lymphoblastic leukemia (T-ALL), characterized by the similar transcriptional and immunophenotypic profiles to those of early T-cell precursors and positive expressions of myeloid antigens. Besides, the gene expression profile in ETP-ALL is similar to that in myeloid malignancies. The clinical characteristics, treatments and prognoses of ETP-ALL are significantly heterogeneous. In the present study, we reported a 43-year-old female patient who lacked terminal deoxynucleotidyl transferase (TDT) expression in immunophenotype and displayed mutations of fms-like tyrosine kinase-internal tandem duplication (FLT3-ITD), paired-box domain 5 (PAX5) and SH2B adaptor protein 3 (SH2B3) (PAX5 and SH2B3, the genes critical to B cell identity and function), which represent myeloid and precursor B-lineage associated gene mutations, respectively. It was a rare T-ALL or T-lineage case. Because of multiple poor prognostic factors in this case, conventional induction regimens, like hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, dexamethasone), were invalid. The patient showed inadequate response, suggesting that this treatment was not employed on the basis of the immunophenotype. FLAG-IDA regimen (fludarabine, cytarabine [Ara-C], granulocyte-colony stimulating factor [G-CSF] and idarubicin), which is usually applied to eliminate leukemia cells, was administered combining with sorafenib as an effective induction chemotherapy. The case achieved long-term survival following the allogeneic hematopoietic stem cell transplantation (allo-HSCT). We recommend that adult ETP-ALL patients can be treated with a myeloid-oriented chemotherapy (as frontline induction treatment) along with gene-targeting inhibitors, followed by allo-HSCT.

Terminal deoxynucleotidyl transferase (TdT)-negative T-cell lymphoblastic lymphoma with loss of the T-cell lineage-specific marker CD3 at relapse: a rare entity with an aggressive outcome

Terminal deoxynucleotidyl transferase (TdT)-negative T-cell lymphoblastic lymphoma is a variant of T-cell lymphoblastic lymphoma/T-cell lymphoblastic leukaemia. TdT is a marker of immaturity expressed in 90%-95% cases of lymphoblastic lymphoma and useful in differentiating it from other mature lymphomas/leukaemias. It has been associated with poorer response to chemotherapy and a more aggressive outcome. Here we present a case of TdT-negative T-cell lymphoblastic lymphoma in a 28-year-old man who presented with superior vena cava syndrome. The patient was treated with hyper-cyclophosphamide,vincristine, Adriamycin, dexamethasone (CVAD), however unfortunately suffered a relapse 1 year later. A unique feature of our case was that on relapse, the patient lost expression of the T-cell lineage-specific marker CD3, which has previously not been reported in association with TdT-negative T-cell lymphoblastic lymphoma. The patient failed to respond to chemotherapy on his relapse and died.

Primary T-cell lymphoblastic lymphoma in the middle ear

T-cell lymphoblastic lymphoma (T-LBL) is a highly aggressive lymphoma characterized by precursor T-cell malignancy and lymphadenopathy or mediastinal involvement. We present the case of an 11-year-old boy with a diagnosis of middle ear T-LBL, which manifested as a headache, hearing loss and peripheral facial paralysis. The child was given intensive chemotherapy and had a complete response. To our knowledge, this is the first case reported in the literature of T-LBL originating in the middle ear. This case aims to help clinicians to be vigilant about the possibility of primary lesions at atypical sites in some special diseases.

Absence of terminal deoxynucleotidyl transferase expression identifies a subset of high-risk adult T-lymphoblastic leukemia/lymphoma

Terminal deoxynucleotidyl transferase (TdT) can be downregulated in minimal residual disease of T-acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) after chemotherapy. TdT-negative T-ALL/LBL cases are rare and have not been well characterized. We studied the clinicopathologic features of de novo T-ALL/LBL patients treated at our institution during 2003-2011, with an emphasis on immunophenotype and survival of TdT-negative versus TdT-positive cases. Absence of TdT expression was defined as <10% lymphoblasts positive. Seven (12%) TdT-negative cases were identified from a cohort of 59 de novo T-ALL/LBL. The TdT-negative and TdT-positive cases were similar with regard to gender, percentage of patients with a high leukocyte count (>100 × 10(9)/l), central nervous system involvement, and an abnormal karyotype. However, patients with TdT-negative T-ALL/LBL had a significantly higher rate of disease progression and shorter overall survival. Although not statistically significant, TdT-negative T-ALL/LBL cases were associated with an older median age and higher percentage of 'early T precursor' (ETP) immunophenotype than TdT-positive cases. Absence of TdT expression identifies a subset of high-risk T-ALL/LBL that overlaps with, but is not identical to, the ETP leukemia, providing additional prognostic value.