Lymphoblastic lymphoma
Lymphoblastic lymphoma is an aggressive precursor lymphoid neoplasm identical to acute lymphoblastic leukemia but presenting as a mass with under 20% marrow blast involvement, classically a T-cell anterior mediastinal mass in an adolescent or young adult male causing respiratory compromise or superior vena cava syndrome. It is diagnosed by biopsy showing TdT-positive lymphoblasts and treated on ALL-type multi-agent chemotherapy protocols with mandatory central nervous system prophylaxis.
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What this article covers
- Overview
Definition: lymphoblastic lymphoma is an aggressive lymphoma of precursor T- or B-lymphoblasts, the same malignant cell as acute lymphoblastic leukemia (ALL), presenting predominantly as a tissue…
- Epidemiology
Age and sex pattern: the T-cell subtype classically affects adolescent and young adult males, presenting with a rapidly enlarging anterior mediastinal mass.
- Risk factors
Age and sex: adolescent or young adult male demographic carries the strongest association with the T-cell, mediastinal presentation.
- Pathophysiology
Clonal precursor lymphoblast proliferation: a malignant clone of T- or B-lymphoblasts, arrested at an immature stage of lymphoid development, infiltrates tissue rather than predominantly the blood and marrow.
- Clinical features
Anterior mediastinal mass: the hallmark of T-lymphoblastic lymphoma, often found on chest imaging for respiratory symptoms; causes wheezing, stridor, cough, and dyspnea from airway compression.
- Differential diagnosis
Acute lymphoblastic leukemia: identical precursor lymphoblasts by immunophenotype, distinguished from lymphoblastic lymphoma by marrow blast burden, not by a different malignant cell (acute lymphoblastic leukemia).
- Diagnosis
Established by tissue biopsy demonstrating TdT-positive lymphoblasts: confirmed histologically and immunophenotypically, with terminal deoxynucleotidyl transferase (TdT) positivity marking the…
- Management
Stabilize mediastinal mass emergencies first: with stridor, significant dyspnea, or hemodynamic compromise from SVC syndrome, secure the airway and hemodynamics before definitive biopsy; avoid…
- Complications
Airway compromise and respiratory failure: direct tracheobronchial compression by the mediastinal mass, the most immediately life-threatening complication at presentation.
- Prognosis
Outcome tracks ALL-type prognosis: biology and treatment mirror ALL, so prognostic factors overlap, including age, lineage, cytogenetics, and response to induction.
- Prevention
No primary prevention exists: no modifiable risk factor or screening test is established, so prevention focuses on pre-empting the disease's emergencies once diagnosed.
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