Hairy cell leukemia (HCL) is a rare type of chronic lymphocytic leukemia. There is no cure for hairy cell leukemia, but current treatments can lead to years of remission. What are the causes and symptoms of hairy cell leukemia? How is it treated and what is the prognosis?

Hairy cell leukemia(hairy cell leukemia - HCL) is a rare disease that is a rather "benign" neoplastic hyperplasia of the B-lineage of the lymphatic system. It accounts for 2 percent of all leukemias and 8 percent of chronic lymphoproliferative diseases.

Hairy cell leukemia owes its name to cells found in the peripheral blood.

These are large lymphoid cells with an oval or kidney-shaped, more rarely round, nucleus, with one or more nucleoli, and a ciliated, jagged cytoplasm that gives them a characteristic "hairy" appearance.

Based on microscopic observation, American researchers Robert Schrek and William J. Donnelly in 1966 proposed that this subtype of leukemia be labeled "hairy cell".

In hairy cell leukemia, these "hairy cells" (cancerous B lymphocytes) accumulate in the spleen and bone marrow, disrupting the production of normal white blood cells, red blood cells, and platelets.

Hairy cell leukemia: causes

As with most leukemias and lymphomas, the etiology of this disease is unknown. So far, no genetic or environmental factors responsible for its occurrence and development have been identified.

On January 23, 2003, the American Institute of Medicine (IOM) released a report titled "Veterans and Agent Orange" which showed that there is a "sufficiently documented link" between herbicide exposure and the subsequent development of chronic lymphocytic leukemias type B (including HCL) and lymphomas in general.

The basis for research in this direction was the poor he alth condition of many veterans who once served in Vietnam, who were then in contact with herbicides.

The following are factors that may increase your likelihood of developing chronic lymphocytic leukemia (CLL), including hairy cell leukemia (HCL):

  • age:medium or older (increased probability of occurrence, especially in old age
  • gender: men get sick four times more often
  • breed: white
  • chronic lymphocytic leukemia or cancer of the lymphatic system from family history
  • people who have relatives who are Eastern European Jews

Hairy cell leukemia: symptoms

  • 85-90 percent of patients have splenomegaly, i.e. enlargement of the spleen, and in 25 percent of them it reaches a very large size - even 7.5 kg!
  • abdominal discomfort with a feeling of excessive fullness and pains in the left hypochondrium resulting from significant splenomegaly
  • lean and fibrotic marrow
  • bleeding tendency in approximately 25 percent of patients due to thrombocytopenia
  • getting tired easily
  • lose weight
  • dizziness
  • usually no accompanying lymphadenopathy - enlarged lymph nodes
  • recurrent neutropenic infections (a haematological condition involving low neutrophil count) in 30 percent, some with infections caused by atypical microorganisms
  • hepatomegaly (enlarged liver) in 30-40 percent of patients

Hairy cell leukemia: diagnosis

  • peripheral blood count with manual smear:

worsening hypochromic anemia with anisocytosis and poikilocytosis - hemoglobin<5,27 mmol/l, mierna lub średniego stopnia pancytopenia, neutropenia i monocytopenia, występowanie komórek "włochatych"

  • cytochemical tests:

95% positive tartrate-resistant acid phosphatase reaction

  • immunophenotyping:

Myelofibrosis and other low-grade lymphomas should be included in the differential diagnosis!

typical: CD11c, CD25, CD103 and HC2 positive, which differentiates HCL and other chronic lymphoproliferative diseases, marrow aspiration is often impossible - "dry biopsy" due to increased fibrosis

  • trepanobiopsy:

reveals focal or diffuse HCL infiltrates, where cells have a characteristic cytoplasmic "halo". The diagnosis is confirmed by immunocytochemistry with anti-CD20 / DBA-44 and anti-TRAP

  • CT (computed tomography) of the abdomen detects enlarged lymph nodes (15-20 percent of patients)

Hairy cell leukemia: treatment

The disease progresses very slowly, sometimes not at all. For this reason, in some patients, often older ones, with or without minimal splenomegaly and cytopenia, the course may only be observed.

In most patients, however, it happens at some pointthe need for treatment. Treatment is required when hemoglobin concentration is below 6.21 mmol / l, neutropenia below 1.0 x 109 / l, thrombocytopenia below 100 x 109 / l, marked splenomegaly, recurrent infections, advancement beyond nodes, autoimmune complications, severe leukemia or a progressive disease. Interestingly, the early initiation of therapy does not significantly increase the patient's chances of extending the remission period. Note that there is no cure for hairy cell leukemia, but current treatments can result in remission for years.
• Supportive management: especially important in the early stages of treatment, when cytopenia increases, is to treat the infection promptly. Pay particular attention to the increased risk of atypical fungal infections.

• Splenectomy (removal of the spleen) is indicated in severe splenomegaly and is beneficial in the treatment of severe pancytopenia in patients with minimal bone marrow infiltration. Drug treatment should be avoided for 6 months after splenectomy.

• Purine analogs are generally accepted in first-line therapy. Requires prophylaxis of P. carini infections and irradiation of blood products.

• Bolus deoxycomfomycin every 1-2 weeks for maximal response plus two cycles. The creatinine clearance should be checked before starting. 75 percent of them go into complete remission.

• Cladribine infusion for 7 days gives a comparable chance of remission, but may be less durable.

• INF-alpha.

• G-CSF useful in patients with profound neutropenia Treatment should be monitored by trepanobiopsy with CD20 / BDA-44 and TRAP staining.

Worth knowing

Hairy cell leukemia: prognosis

There is no classification of the severity of the disease. Treatment response is probably the best prognostic factor. Increased abdominal lymphadenopathy at diagnosis correlates with a poor response to first-line treatment.

Hairy cell leukemia allows 95 percent of patients to survive for 5 years. Some people may achieve long-term remission with modern treatment. For others, careful treatment for relapsed (progressive) disease may result in prolonged, good-quality survival. If remission is achieved for more than 5 years, then further remission is likely with the same drug.

Category:

Oncology