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Anaplastic Large Cell Lymphoma: Muscle

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Characteristics

• Non-Hodgkin lymphoma, high grade
• Malignant proliferation of large & often bizarre lymphoid cells
• Cells: 2 types
  • Mononucleated
    • Cytoplasm: Prominent, Basophilic, Vacuolated
    • Nuclei: Eccentric, Multi-lobulated
    • Cell morphologic variants
      • Common
      • Lymphohistiocytic
      • Small cell
  • Multinucleated
    • Nuclear distribution: "Wraith-like"
    • Nucleoli: Prominent
• Molecular markers
  • CD30 (Cytokine receptor; Ki-1): 100%
    • Also present on: Hodgkin & Reed-Sternberg cells of classic Hodgkin disease
  • Epithelial membrane antigen (EMA): 75%
  • ALK expression: Some ALCL
    • ALK+
      • Males in the first three decades
      • Caused by chromosomal translocations: Most commonly t(2;5)
    • ALK-
      • Older patients
      • Poorer prognosis
      • Neoplasm: More pleomorphic cells
  • PAX5, Desmin & CD15: Negative (Positive in Hodgkin's lymphoma)
  • Lymphocyte phenotype: T-cell (60% to 70%); B-cell (10% to 20%); Null (10% to 30%)

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Clinical: ALCL

• Frequency: 3% of adult & 10% of childhood NHL
• Types
  • Primary systemic
    • Locations: Usually lymph nodes; Occasionally muscle
      • Extranodal features: Waldayer’s ring, skin, lung, bone, soft tissue, respiratory & GI
    • Muscle involvement: Rare
      • Mass: Most common
      • Rhabdomyolysis
      • Compartment syndrome
      • Pain
      • Source: May be dissemination or primary
      • Skeletal muscle lymphoma: Differential diagnosis
        • ALCL
        • Non-Hodgkin lymphoma: B- or T-cell
        • Large B-cell lymphoma
        • Marginal zone lymphoma
        • Follicle center cell lymphoma
  • Primary cutaneous
    • Sub-types: de novo; Extranodal spread
    • de novo: Indolent course

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Pathology: ALCL

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Return to: Neuromuscular Home Page

References
1. Diagn Cytopathol 2010;38:208-212

2/5/2018