Chapter12- PERIPHERAL B-CELL NEOPLASMS:Hairy Cell Leukemia Flashcards
What is Hairy Cell Leukemia?
- rare
- but distinctive B-cell neoplasm
- constitutes about 2% of all leukemias.
- middle-aged white males,
- with a median age of 55
- male-tofemale ratio of 5 : 1.
” Mas hairy ang WHITE and MALES! “
Hairy cell leukemia derives its picturesque name from what?
the appearance of the leukemic cells, which have fine hairlike projections that are best recognized
under the phase-contrast microscope ( Fig. 13-21 ).
On routine peripheral blood smears, what is the appearanc of :Hairy Cell Leukemia?
- hairy cells have round, oblong, or reniform nuclei and moderate amounts of pale blue cytoplasm with threadlike or bleblike extensions.
- The number of circulating cells is highly variable.
- The marrow is involved by a diffuse interstitial infiltrate of cells with oblong or
- reniform nuclei, condensed chromatin, and pale cytoplasm.
What is the reason why Hairy Cell Leukemia cannot be aspirated?
Because these cells are
enmeshed in an extracellular matrix composed of reticulin fibrils, they usually cannot be aspirated (a clinical difficulty referred to as a “dry tap”) and are only seen in marrow biopsies.
What is a dry tap?
A clinical difficulty wherein there is difficulty in aspiration, for example in the case of Hairy Cell Leukemia, the cell are enmeshed in an extracellular matrix composed of reticulin fibrils and are only seen in marrow biopsies.
What is the apperance of the spleen in Hairy cell leukemia?
The splenic red pulp is usually heavily infiltrated, leading to obliteration of white pulp and a beefy red gross appearance.
Hepatic portal triads are also involved frequently
FIGURE 13-21 Hairy cell leukemia (peripheral blood smear). A, Phase-contrast
microscopy shows tumor cells with fine hairlike cytoplasmic projections. B, In stained
smears, these cells have round or folded nuclei and modest amounts of pale blue,
agranular cytoplasm
What is the immunophenotype and molecular pathogenesis of Hairy cell leukemia?
Hairy cell leukemias typically express the pan-B-cell markers CD19 and CD20, surface Ig (usually IgG), and certain relatively distinctive markers, such as CD11c, CD25, and CD103.
Analysis of Ig gene sequences has revealed a high incidence of somatic hypermutation,
suggesting a post-germinal center memory B-cell origin.
The Clinical manifestations of Hairy Cell Leukemia result largely from infiltration of what?
the bone marrow, liver, and spleen.
What is the most common and sometimes the only abnormal physical finding in Hairy Cell Leukemia?
Splenomegaly, often massive,.
What are the clinical features of Hairy Cell Leukemia?
- Splenomegaly, often massive, is the most common and sometimes the only abnormal physical finding.
- Hepatomegaly is less common and not as marked; lymphadenopathy is rare.
- Pancytopenia resulting from marrow involvement and splenic sequestration is seen in more than half the cases.
- About one third of those affected present with infections. There is an increased incidence of atypical mycobacterial infections, possibly related to frequent unexplained monocytopenia.
Why does about one third of Hairy cell leukemia those affected present with infections which has an increased incidence of atypical mycobacterial infections?
possibly related to frequent unexplained monocytopenia.
What is the course of Hairy cell leukemia?
follows an indolent course.
For unclear reasons, this tumor is exceptionally
sensitive to “gentle” chemotherapeutic regimens, which producelong-lasting remissions.
Tumors often relapse after 5 or more years, yet generally respond well when retreated with
chemotherapy. The overall prognosis is excellent
What is the overall prognosis of Hairy cell leukemia?
excellent
