Page 394 - Textbook of Pathology, 6th Edition

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Figure 14.22 Burkitt’s lymphoma. The tumour shows uniform cells having high mitotic rate. Scattered among the tumour cells are benign
macrophages surrounded by a clear space giving ‘starry sky’ appearance.
SECTION II

MORPHOLOGIC FEATURES. Histologically all three MORPHOLOGIC FEATURES. It is characterised by
types of Burkitt’s lymphoma are similar. Tumour cells are diffuse infiltration by monoclonal small B lymphocytes
intermediate in size, non-cleaved, and homogeneous in which are negative for CD5.
size and shape. The nuclei are round to oval and contain
2-5 nucleoli. The cytoplasm is basophilic and contains lipid MALT lymphoma has a good prognosis. Rarely, it may
vacuolation. The tumour cells have a very high mitotic be more aggressive and may metastasise, or transform into
rate, and therefore high cell death. This feature accounts diffuse large B-cell lymphoma.
for presence of numerous macrophages in the background
of this tumour containing phagocytosed tumour debris MANTLE CELL LYMPHOMA
giving it a ‘starry sky’ appearance (Fig. 14.22). This subtype of NHL comprises about 8% of all NHLs. It
Burkitt’s leukaemia is identified by classical appearance
of monomorphic medium-sized cells having round nuclei, was earlier included in SLL but has been identified as a
separate subtype due to characteristic chromosomal
frequent mitoses, multiple nucleoli, and basophilic translocation, t(11;14) and overexpression of BCL-1 and
cytoplasm with vacuoles. surface immunoglobulins IgM and IgD protein. However,
Immunophenotypically, the tumour cells are positive
for CD19 and CD10 and surface immunoglobulin IgM. both SLL and mantle cell NHL are positive for CD5 antigen.
Patients of mantle cell lymphoma are generally older males.
Typical cytogenetic abnormalities in the tumour cells are The disease involves bone marrow, spleen, liver and bowel.
t(8;14) and t(8;22) involving MYC gene on chromosome
8, with overexpression of MYC protein having trans- MORPHOLOGIC FEATURES. Mantle cell lymphoma
forming activity. arises from B-cells of mantle zone of normal lymphoid
Haematology and Lymphoreticular Tissues
Burkitt’s lymphoma is a high-grade tumour and is a very follicle. The tumour cells show diffuse or nodular pattern
rapidly progressive human tumour. of involvement in the lymph node and have somewhat
indented nuclei.
EXTRANODAL MARGINAL ZONE B-CELL LYMPHOMA It is more aggressive than other types of SLLs.
OF MALT TYPE (SYNONYM: MALTOMA)
This type comprises about 8% of all NHLs. In the earlier HAIRY CELL LEUKAEMIA
classification, it was included under SLL, but in the WHO Hairy cell leukaemia (HCL) is an unusual and uncommon
scheme it is categorised separately for 2 reasons: etiologic form of B-cell malignancy characterised by presence of hairy
association with H. pylori infection and occurrence at cells in the blood and bone marrow and splenomegaly. It
extranodal sites. Most frequent is gastric lymphoma of MALT occurs in the older males. HCL is characterised clinically by
type with its characteristic etiologic association with H. pylori; the manifestations due to infiltration of reticuloendothelial
other extranodal sites for this subtype of NHL are intestine, organs (bone marrow, liver and spleen) and, hence, its
orbit, lung, thyroid, salivary glands and CNS. About half previous name as leukaemic reticuloendotheliosis. Patients have
the cases of gastric MALT lymphoma show Genetic mutation susceptibility to infection with M. avium intercellulare.
t(11;18). Median age for this form of NHL is 60 years and
often remains localised to the organ of origin but may MORPHOLOGIC FEATURES. Laboratory diagnosis is
infiltrate the regional lymph nodes. made by the presence of pancytopenia due to marrow