Haemoblastosis
*Haemoblastosis*
For medical students2 min readUpdated 2026-10-10
Haemoblastoses are a group of neoplastic diseases affecting the hematopoietic and lymphoid tissues. They are fundamentally driven by the malignant transformation of blood cells at various stages of their development.
Two groupsThe diseases are divided into leukemias (involving the bone marrow) and lymphomas (involving lymphoid organs).
Leukemic infiltratesNeoplastic cells accumulate around blood vessels, causing the destruction of organ parenchyma.
MetastasisSpread of tumor cells occurs via hematogenous dissemination, affecting the liver, spleen, and lymph nodes.
Classification of Haemoblastoses
Depending on the primary site of tumor growth, two main types are distinguished:
- Leukemias (leukemia): Primary neoplasms of the bone marrow. The tumor substrate consists of stem cells or pluripotent cells that have undergone malignant transformation directly within the bone marrow tissue.
- Lymphomas: Monoclonal tumors arising from lymphoid cells at various stages of differentiation. They develop either before or after contact with central organs of lymphopoiesis (the thymus, lymph nodes, or spleen).
Morphology and Dissemination Features
A key characteristic of leukemias is the ability of neoplastic cells to undergo hematogenous dissemination. Organ involvement typically proceeds in two stages:
- Primary stage: Involvement of hematopoietic organs (spleen, liver, lymph nodes).
- Secondary stage: Involvement of other tissues and organs throughout the body.
Microscopically, this manifests as the formation of leukemic infiltrates. These are located in the interstitium, surrounding blood vessels and invading their walls. Such diffuse infiltration inevitably leads to the destruction of the functional parenchyma of the affected organ.
Mnemonic
Leukemia = "bone marrow" (inside), Lymphoma = "lymph nodes" (outside).
Frequently asked questions
- Which organs are considered central organs of lymphopoiesis in the context of lymphoma development?
In the context of lymphoma development, central organs of lymphopoiesis include the thymus, lymph nodes, and spleen.
Lymphomas arise either before or after contact of the malignant lymphatic cell (at various levels of differentiation) with these organs. In general immunological classification, the central (primary) lymphoid organs, where antigen-independent differentiation takes place, include:
- Thymus — ensures T-lymphocyte maturation.
- Bone marrow — ensures the development of B-lymphocytes and natural killer (NK) cells.
- What is the main difference between leukemia and lymphoma?
Leukemia primarily affects the bone marrow, whereas lymphomas develop from lymphatic cells within lymphoid organs.
- Why does organ parenchyma destruction occur in leukemias?
Due to the formation of diffuse leukemic infiltrates around blood vessels, which disrupt tissue architecture and blood supply.
- Which organs are primarily affected in leukemias?
Hematopoietic-related organs are affected first: the spleen, liver, and lymph nodes.
Go deeper
Cytogenetic basis of stem cell transformation
Differential diagnosis of leukemia subtypes
Stages of lymphoma development relative to thymic contact
Comparative characteristics of diffuse versus nodular infiltration
Impact of cell differentiation grade on disease prognosis
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