The treatment of hematologic malignancies is specifically challenging. Hematologic malignancies have a diverse and heterogeneous etiology and genetic pathophysiology. This exceptional diversity results in complex diagnoses and treatments of these cancers.
The three most common blood cancers are leukemia, multiple myeloma, and lymphoma. While these malignancies all start in the bone marrow, major differences exist among these cancers. This overview compares the symptoms, diagnostic workup, and treatment options for multiple myeloma, leukemia, and lymphoma.
How Rare Are Hematologic Malignancies?
The American Cancer Society projects that approximately 1.9 million patients will be diagnosed with cancer in the US in 2022. Hematologic malignancies comprise approximately 10% of these total incident cancer cases . Lymphoma accounts for roughly 50%, leukemia 30%, and multiple myeloma 20% of all incident hematologic cancers.
Lymphoma is divided into Hodgkin and Non-Hodgkin Lymphomas (NHL). Hodgkin lymphoma usually affects young adults, most commonly young men, except for one variant (nodular sclerosis), which affects young females. Symptoms of Hodgkin lymphoma include fever, diaphoresis, pruritis, and leukocytosis. Hodgkin Lymphoma is characterized by the presence of Reed-Sternberg, or “popcorn” cells, and has a better prognosis than NHL. The Reed-Sternberg cell variants get their name from their multi-lobated, or extremely folded nucleus. Hodgkin lymphomas are further classified as “classical” and nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL).
Non-Hodgkin lymphoma is a malignant neoplasm that arises from lymphoid tissues originating from B-cells and T-cells. Common B-cell Non-Hodgkin lymphoma subtypes are follicular lymphoma, Burkitt lymphoma, diffuse large B-cell lymphoma, and mantle cell lymphoma. Common T-cell lymphomas include Adult T-cell lymphoma and mycosis fungoides. Overall, Non-Hodgkin lymphoma tends to affect adults older than 60 years of age at the time of diagnosis. Non-Hodgkin lymphoma patients typically present with complaints of fever, weight loss, or night sweats as well as peripheral lymphadenopathy .
Biopsies are taken, and a histopathological examination is done to confirm the type of lymphoma. Both Hodgkin and Non-Hodgkin lymphoma have many sub-variants, complicating the diagnosis. With modern staging systems and aggressive treatment therapies, both types of lymphoma can be treatable if diagnosed early .
Non-Hodgkin lymphoma is the most common lymphoma variant Hematopathologists play an important role in diagnosing these cases properly. Lymph node biopsy is usually taken, and the specimen is examined to look for characteristic findings. Generally, the tests below are leveraged:
- Physical examination
- Lymph node biopsy
- Blood tests
- Flow cytometry
- Cytogenetic analysis
- Gene expression profiling and microarray analysis