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Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Peripheral smear description | Positive stains | Negative stains | Flow cytometry description | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosisCite this page: Lymphoblastic lymphoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bonelymphoblasticlymphoma.html. Accessed July 14th, 2017.
Definition / general
- Lymphoblastic lymphoma (LBL) is a clonal hematopoietic stem cell disorder committed to early B or T cell differentiation
- LBL is characterized by the presence of immature blasts, with minimal morphologic evidence of differentiation
- See also Lymphoma chapter
Terminology
- Lymphoblastic lymphoma (LBL) and Acute Lymphoblastic Leukemia (ALL) are combined into the term acute lymphoblastic lymphoma / leukemia, due to the significant overlap between clinical and biological features
- Leukemia is designated when the disease involves peripheral blood and bone marrow
- By definition, lymphoma involves mainly nodal and extranodal sites, with < 25% bone marrow blasts
Epidemiology
- LBL accounts for 2% of all NHL
- T- LBL constitutes ~90% of lymphobastic lymphoma / leukemia, while B-LBL constitutes 10%
Sites
- T-LBL frequently involves mediastinum
- B-LBL most commonly involves skin, bone is #2 most common site (Am J Surg Pathol 2000;24:1480)
- B-LBL reported in femur, tibia, humerus, vertebrae, scapula, foot and rib; can occur in multiple bony sites
Clinical features
- Bone pain mimicking inflammatory lesion
- Gait disturbances
- Vertebral body collapse and related symptoms
Diagnosis
- Diagnosis based on clinical, morphologic, immunophenotyping, molecular features
- Molecular studies are essential for diagnosis, prognosis, classification, and treatment
Radiology description
- Nonspecific, variable
- Lytic, sclerotic, or lytic and sclerotic lesions
- Diffuse osteopenia
- Periosteal new bone formation
- Metaphyseal bands
Radiology images
Images hosted on other servers:
Multiple lytic areas
Lytic destruction of vertebral body
Irregular lytic lesion with intense periostal reaction
Progressive lesion on left side
Progressive osteodestructive process
Abnormally high signal intensity in T11 vertebral body
Radionuclide and PET
Prognostic factors
- Number of bones involved, stage (St. Jude Children Research Hospital Staging System)
Case reports
- 2 year old boy with extensive skeletal lesions in childhood acute lymphoblastic leukemia (Mymensingh Med J 2009;18:88)
- 13 year old boy with primary bone lymphomas thought to be osteomyelitis (Anticancer Res 2012;32:4905)
- 27 year old man with solitary lymphoblastic lymphoma of thoracic spine (J Korean Neurosurg Soc 2012;52:564)
- Precursor B cell lymphoblastic lymphoma / leukemia presenting as osteoblastic bone lesions (Ann Diagn Pathol 2002;6:236)
Treatment
- Chemotherapy
Microscopic (histologic) description
- Diffuse pattern
- Starry sky appearance may be seen, at least focally
- Lymphoblasts are small to medium sized cells, with minimal cytoplasm, nuclei larger than histiocytes, high N / C ratio, fine dusty “salt and pepper” chromatin, absent to inconspicuous nucleoli, irregular nuclear contour
- In some cases, cells have abundant cytoplasm and prominent nucleoli
Microscopic (histologic) images
Images hosted on other servers:
Malignant small round cells
CD34+, MIB1+
Cytology description
- Hypercellular smears with uniform, medium sized lymphoid blasts
- Minimal cytoplasm with no / few cytoplasmic vacuoles; cytoplasmic pseudopods project from cell in a "hand mirror" pattern
- Nuclei are round to convoluted with finely granular “dusty” chromatin and inconspicuous nucleoli
- In some cases, lymphoblasts are larger with more cytoplasm and prominent nucleoli
- Tingible body macrophages may be seen
Peripheral smear description
- Lymphoblasts may be seen as either medium sized cells with scant cytoplasm, distinct chromatin and indistinct nucleoli; or large cells with moderate cytoplasm, dispersed chromatin, and multiple nucleoli
Positive stains
Flow cytometry description
- Optimal method to assess markers simultaneously and quantitatively
Electron microscopy description
- Lymphoblasts are medium sized cells with scanty cytoplasm with few organelles, high N / C ratio, irregular nuclei with frequent convolusions, evenly dispersed chromatin with peripheral condensation, and dense nucleoli adjacent to nuclear membrane
Molecular / cytogenetics description
- Characteristic molecular abnormalities correlate with immunophenotyping: 11q 23 translocation, t(9;22), t(12;21)
Differential diagnosis
- Small blue cell tumors of bone
- Neuroblastoma: rosettes and neuroendocrine marker positivity
- Ewing Sarcoma: CD99 positivity
- Osteosarcoma, small cell variant: osteoid
- Mesenchymal chondrosarcoma: chondroid differentiation, S100+
- Other hematologic neoplasms (by morphology and immunophenotyping)
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