Lecture Notes on Lymphomas

Overview of Lymphomas

• Lymphomas: Heterogeneous group of malignancies from B cells, T cells, or NK cells.
• Origin: Lymph nodes or extranodal tissue.
• Types: Non-Hodgkin lymphomas are more common than Hodgkin lymphomas.
• Causes: Chromosomal translocations and infections.

Key Distinction

• Hodgkin Lymphoma (HL): Presence of Reed-Sternberg cells.
• Non-Hodgkin Lymphoma (NHL): Absence of Reed-Sternberg cells.

Hodgkin Lymphoma

• Subtypes: Classical and non-classical.
• Reed-Sternberg Cells: Large binucleate lymphocytes with eosinophilic nuclei.

Non-Hodgkin Lymphoma

• Divided into B cell and T cell lymphomas.

B Cell Non-Hodgkin Lymphomas

• Burkitt Lymphoma:

  • Common in children and young adults.
  • Chromosomal translocation 8;14.
  • Subtypes: Endemic (associated with EBV), sporadic, and immunodeficiency.
  • Histology: Starry Sky pattern.

• Diffuse Large B Cell Lymphoma (DLBCL):

  • Most common NHL in adults.
  • Mutations: BCL2, BCL6, p53.

• Follicular Lymphoma:

  • Most common low-grade B cell lymphoma.
  • Chromosomal translocation 14;18.
  • Histology: Presence of centrocytes and centroblasts.

• Mantle Cell Lymphoma:

  • Common in adult males.
  • Chromosomal translocation 11;14.
  • Rapid spread and advanced diagnosis.

• Marginal Zone Lymphoma:

  • Chromosomal translocation 11;18.
  • Association: Autoimmune diseases, gastric MALT, H. pylori infection.

T Cell Non-Hodgkin Lymphomas

• Mycosis Fungoides:

  • Most common low-grade T cell lymphoma.
  • CD4+ T cell infiltration of skin.
  • Features: Patches, plaques, nodules, Sezary cells.

• Adult T Cell Lymphoma:

  • Associated with HTLV-1, IV drug abuse.
  • Features: Elevated LDH, calcium, hepatosplenomegaly.

Clinical Features

• Symptoms: B symptoms (fever, night sweats, weight loss).
• Age: HL bimodal (young adults, 55+); NHL increases with age.
• Spread: HL - local, contiguous; NHL - extranodal, non-contiguous.
• Associations:
  • HL: Immunosuppression, EBV.
  • NHL: Chromosomal translocations, autoimmune conditions.

Associated Syndromes

• Tumor Lysis Syndrome:

  • Cause: Release of intracellular components after tumor cell destruction.
  • Features: Hyperphosphatemia, hyperkalemia, hypocalcemia, hyperuricemia.

• Superior Vena Cava Syndrome:

  • Cause: Obstruction of SVC.
  • Features: Edema, JVD, neurological symptoms.

Important Concepts

• Know chromosomal translocations and their associated lymphomas.
• Understand the significance of Reed-Sternberg cells.
• Recognize key histological patterns and clinical syndromes.

This concludes the lecture on lymphomas, covering essential information for exams such as USMLE and COMLEX.