Page 395 - Textbook of Pathology, 6th Edition

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Figure 14.23 Hairy cell leukaemia. A, Peripheral blood shows presence of a leukaemic cells with hairy cytoplasmic projections B, Trephine CHAPTER 14
biopsy shows replacement of marrow spaces with abnormal mononuclear cells.

chapter. There is infiltration by IgM-secreting monoclonal
failure and splenic sequestration, and identification of
characteristic hairy cells in the blood and bone marrow. lymphoplasmacytic cells into lymph nodes, spleen, bone
Hairy cells are abnormal mononuclear cells with hairy marrow, and sometimes in the peripheral blood. It behaves
cytoplasmic projections which are seen in the bone like an indolent B-cell lymphoma. Etiologic association of
this form of lymphoma with hepatitis C virus infection has
marrow, peripheral blood and spleen. These cells are best also been proposed.
recognised under phase contrast microscopy but may also
be visible in routine blood smears (Fig. 14.23). These iv) Nodal marginal zone lymphoma (monocytoid B-cell lymphoma)
leukaemic ‘hairy cells’ have characteristically positive is another uncommon subtype of aggressive NHL. At
cytochemical staining for tartrate-resistant acid phosphatase presentation, the patients often have disseminated disease,
involving bone marrow and leukaemic picture.
(TRAP).
The controversy on the origin of hairy cells whether PERIPHERAL(MATURE) T-CELL MALIGNANCIES
these cells represent neoplastic T cells, B cells or Disorders of Leucocytes and Lymphoreticular Tissues
monocytes, is settled with the molecular analysis of these Peripheral or mature T-cell lymphoid malignancies are
cells which assigns them B cell origin expressing CD19, relatively less common compared to mature B cell cancers.
CD20 and CD22 antigen. In addition to B cell markers, These arise at the stage when the lymphoid cells migrate to
hairy cells are also positive for CD11, CD25 and CD103. thymus and become committed to T-cell differentiation by
acquiring T cell antigen receptor genes. A few common
The disease often runs a chronic course requiring examples are discussed below.
supportive care. The mean survival is 4-5 years. Patients
respond to splenectomy, α-interferon therapy and 2- MYCOSIS FUNGOIDES/SÉZARY SYNDROME
chlorodeoxyadenosine (2-CDA). Mycosis fungoides is a slowly evolving cutaneous T-cell
lymphoma occurring in middle-aged adult males.
OTHER B-CELL MALIGNANCIES
MORPHOLOGICAL FEATURES. The condition is often
Brief mention is made below on the other types of B-cell preceded by eczema or dermatitis for several years
malignant tumours given in the WHO classification in (premycotic stage). This is followed by infiltration by CD4+T-
Table 14.8: cells in the epidermis and dermis as a plaque (plaque stage)
i) B-cell prolymphocytic leukaemia is involvement of blood and and eventually as tumour stage. The disease may spread to
bone marrow by large B lymphocytes having prominent viscera and to peripheral blood as a leukaemia
nucleoli. These patients have leucocytosis with splenomegaly characterised by Sézary cells having cerebriform nuclei
and lymphadenopathy. termed as Sézary syndrome.
ii) Splenic marginal zone lymphoma is another uncommon B- Mycosis fungoides/Sézary syndrome is an indolent NHL
cell neoplasm in which the splenic white pulp is infiltrated and has a median survival of 8 to 9 years.
by small monoclonal B lymphocytes. The condition has a
slow and indolent behaviour. ADULT T-CELL LYMPHOMA/LEUKAEMIA (ATLL)
iii) Lymphoplasmacytic lymphoma is tissue manifestation of This is an uncommon T-cell malignancy but has gained much
Waldenström’s macroglobulinaemia, discussed later in this prominence due to association with retrovirus, human T-cell