Tumors of the hematopoietic and lymphoid tissues (
American English) or tumours of the haematopoietic and lymphoid tissues (
British English) are
tumors that affect the
blood,
bone marrow,
lymph, and
lymphatic system.[1][2] Because these tissues are all intimately connected through both the
circulatory system and the
immune system, a disease affecting one will often affect the others as well, making
aplasia,
myeloproliferation and
lymphoproliferation (and thus the
leukemias and the
lymphomas) closely related and often overlapping problems.
While uncommon in solid tumors,
chromosomal translocations are a common cause of these diseases. This commonly leads to a different approach in diagnosis and treatment of hematological malignancies.
Hematological malignancies are malignant
neoplasms ("cancer"), and they are generally treated by specialists in
hematology and/or
oncology. In some centers "hematology/oncology" is a single subspecialty of
internal medicine while in others they are considered separate divisions (there are also surgical and radiation oncologists). Not all
hematological disorders are malignant ("cancerous"); these other blood conditions may also be managed by a hematologist.
A subgroup of them are more severe and are known as haematological malignancies (
British English)/hematological malignancies (
American English) or blood cancer. They may also be referred to as liquid tumors.[3][4]
Diagnosis
For the analysis of a suspected hematological malignancy, a
complete blood count and
blood film are essential, as malignant cells can show in characteristic ways on
light microscopy. When there is
lymphadenopathy, a
biopsy from a
lymph node is generally undertaken
surgically. In general, a
bone marrow biopsy is part of the "work up" for the analysis of these diseases. All specimens are examined microscopically to determine the nature of the malignancy. A number of these diseases can now be classified by
cytogenetics (AML, CML) or
immunophenotyping (lymphoma, myeloma, CLL) of the malignant cells.[citation needed]
Classification
Historically, hematological malignancies have been most commonly divided by whether the malignancy is mainly located in the blood (
leukemia) or in
lymph nodes (
lymphomas).
Relative proportions of hematological malignancies in the United States[5]
Chronic lymphocytic leukemia (CLL) sorted under lymphomas according to current WHO classification; called small lymphocytic lymphoma (SLL) when leukemic cells are absent.
Other iatrogenic immunodeficiency- associated lymphoproliferative disorders
Histiocytic and dendritic cell neoplasms
Histiocytic sarcoma
Langerhans cell histiocytosis, NOS
Langerhans cell histiocytosis, monostotic
Langerhans cell histiocytosis, polystotic
Langerhans cell histiocytosis, disseminated
Langerhans cell sarcoma
Indeterminate dendritic cell tumour
Interdigitating dendritic cell sarcoma
Follicular dendritic cell sarcoma
Fibroblastic reticular cell tumour
Disseminated juvenile xanthogranuloma
Erdheim–Chester disease
Treatment
Treatment can occasionally consist of "watchful waiting" (e.g., in
CLL) or symptomatic treatment (e.g.,
blood transfusions in
MDS). The more aggressive forms of disease require treatment with
chemotherapy,
radiotherapy,
immunotherapy and—in some cases—a
bone marrow transplant. The use of
rituximab has been established for the treatment of B-cell–derived hematologic malignancies, including follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL).[7]
In addition to cure-directed treatment, people can benefit from
self-care to manage symptoms. For example, aerobic exercise, such as
walking, can reduce
fatigue and feelings of
depression in people with hematological malignancies.[8]
Follow-up
If treatment has been successful ("complete" or "partial remission"), a person is generally followed up at regular intervals to detect recurrence and monitor for "secondary malignancy" (an uncommon side-effect of some
chemotherapy and
radiotherapy regimens—the appearance of another form of
cancer). In the follow-up, which should be done at pre-determined regular intervals, general
anamnesis is combined with
complete blood count and determination of
lactate dehydrogenase or
thymidine kinase in serum. Hematological malignancies as well as their treatments are associated with complications affecting many organs, with the lungs being frequently affected[9][10]
Taken together, haematological malignancies account for 9.5% of new cancer diagnoses in the United States[13] and 30,000 patients in the UK are diagnosed each year.[14] Within this category, lymphomas are more common than leukemias.[citation needed]
^Horner MJ, Ries LAG, Krapcho M, Neyman N, et al. (eds).
"SEER Cancer Statistics Review, 1975–2006". Surveillance Epidemiology and End Results (SEER). Bethesda, MD:
National Cancer Institute. Retrieved 3 November 2009. Table 1.4: Age-Adjusted SEER Incidence and U.S. Death Rates and 5-Year Relative Survival Rates By Primary Cancer Site, Sex and Time Period{{
cite web}}: CS1 maint: multiple names: authors list (
link)
^al.], edited by Steven H. Swerdlow ... [et (2008). WHO classification of tumours of haematopoietic and lymphoid tissues (4th. ed.). Lyon, France: International Agency for Research on Cancer. p. 10.
ISBN978-9283224310. {{
cite book}}: |first1= has generic name (
help)
^Br J Hosp Med (Lond). 2014 Dec;75(12):691–7.
Non-infectious respiratory disease in non-HIV immunocompromised patients.
Jose RJ1, Faiz SA, Dickey BF, Brown JS.
doi:
10.12968/hmed.2014.75.12.691.
^Br J Hosp Med (Lond). 2014 Dec;75(12):685–90.
Infectious respiratory disease in non-HIV immunocompromised patients.
Jose RJ1, Dickey BF, Brown JS. PMID 25488531
doi:
10.12968/hmed.2014.75.12.685
^
abValikhani M, Rahimian E, Ahmadi SE, Chegeni R, Safa M. Involvement of classic and alternative non-homologous end joining pathways in hematologic malignancies: targeting strategies for treatment. Exp Hematol Oncol. 2021 Nov 3;10(1):51. doi: 10.1186/s40164-021-00242-1. PMID 34732266; PMCID: PMC8564991
^Senapati J, Sasaki K. Chromosomal Instability in Chronic Myeloid Leukemia: Mechanistic Insights and Effects. Cancers (Basel). 2022 May 21;14(10):2533. doi: 10.3390/cancers14102533. PMID 35626137; PMCID: PMC9140097