Page 351 - Concise Pathology for Exam Preparation ( PDFDrive )

336 SECTION II Diseases of Organ Systems

- Lymphocytic, poorly differentiated
- Lymphocytic and histiocytic mixed
- Histiocytic
(ii) Diffuse NHL
- Lymphocytic, well differentiated
- Lymphocytic, poorly differentiated
- Mixed lymphocytic and histiocytic
- Lymphoblastic
- Diffuse undifferentiated, Burkitt’s and non-Burkitt’s.
Disadvantages of Rappaport classification:
• No T-cell and B-cell subpopulation identification
• Cell of origin not identified
2. Luke–Collins/Kiel classification (1974)
(a) Immunologic markers divide all lymphomas into B cell, T cell and, rarely, NK cell
derived.
(b) Sixty-five percent of NHL are B lymphocyte derived.
Classifies NHLs into:
(i) B-cell NHL
- Small lymphocytic
- Plasmacytoid lymphocytic
- Follicular centre cell
- Immunoblastic
(ii) T-cell NHL
- Small lymphocytic
- Convoluted lymphocytic
- Cerebriform
- Immunoblastic
(iii) Histiocytic NHL
(iv) Undefined NHL
Disadvantage of Luke–Collins/Kiel classification: Does not correlate with varying progno-
sis of different clinical types of NHL
3. Working formulation for clinical usage (1982): Based on normal history of disease
and long-term survival studies. Classifies NHLs into:
(a) Low-grade NHL: 5-year survival is 50–70%.
(i) Small lymphocytic
(ii) Follicular and predominantly small cleaved
(iii) Follicular, mixed small cleaved and large cleaved
(b) Intermediate-grade NHL: 5-year survival is 35–45%.
(i) Follicular and predominantly large cell
(ii) Diffuse and small cleaved cell
(iii) Diffuse mixed small and large cell
(iv) Diffuse and large cell
(c) High-grade NHL: 5-year survival is 25–35%.
(i) Large cell immunoblastic
(ii) Lymphoblastic
(iii) Burkitt’s
Disadvantage of Working formulation classification: No attempt is made to determine
whether the tumour cells are B cell or T cell or macrophage in origin.
4. Updated REAL (Revised European-American classification)/WHO classification
(2008): In 1994 REAL classification was proposed, however in view of the fact that it
showed poor reproducibility, it is not used anymore. Since 1995, members of the
European and American haematopathology societies have been collaborating on a new
World Health Organization (WHO) classification of haematological malignancies.
WHO classification uses an updated version of the REAL classification for lymphomas
and extends the principles of the REAL classification to the classification of myeloid
and histiocytic neoplasms. The REAL and WHO classifications recognize three major
categories of lymphoid malignancies that can be defined on the basis of a combination
of morphology and special studies that identify cell lineage: B-cell neoplasms, T-cell/
natural killer (NK)-cell neoplasms and Hodgkin disease/Hodgkin lymphoma (HD).

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