1. Hodgkin lymphomas (NL Harris) and lymphoid hyperplasias and
their differential diagnosis with lymphomas (JKC Chan). The goal
is to provide guidance related to practicing state-of-the-art lym-phoma
pathology in 2014.
Hematopathology: LC14-1
DIFFUSE LARGE B-CELL LYMPHOMA (DLBCL): STILL
A PANDORA’S BOX?
Stefano A. Pileri
Chair of Pathology and Haematopathology Unit, Department of
Experimental, Diagnostic and Specialty Medicine, Bologna
University School of Medicine, Bologna, Italy
DLBCL is the most common lymphoid malignancy worldwide. It
includes tumors that cannot be morphologically classified (NOS)
and clinic-pathologic variants characterized by specific features
(e.g., age, primary site, immunodeficiency, and/or relationship
with infectious agents).Nowadays, the cell of origin and complex
cytogenetic alterations deserve great attention by affecting the
disease behavior and therapeutic decisions.
Gene expression profiling (GEP) studies have subdivided
DLBCL/NOS into two main categories, related to germinal center
and activated blood B-lymphocytes. The former has a more
favorable course also in thepresent immunochemotherapy era.
The attempts to surrogate GEP by immunohistochemistry ensued
in algorithms, none of which as effective as GEP. More recently,
an approach based on 15 genes and Nanostring technology has
revealed excellent accuracy, inter-lab reproducibility and afford-able
costs.
Equally important is the search for double/triple hits involving
BCL2, MYC and BCL6, which can be detected by FISH and confer
protection against apoptosis and high proliferative activity. The
search for the corresponding proteins does not represent an
absolute surrogate of cytogenetics. However, BCL2/MYC double
expression heralds a poor prognosis. Further relevant parameters
are CD30 expression and EBV infection.
Finally, next generation sequencing has highlighted a series of
mutations that might represent the rationale for innovative-targeted
therapies.
Hematopathology: LC14-1
SMALL B-CELL LYMPHOMAS. DIAGNOSIS OF
MALIGNANT LYMPHOMAS IN 2014
Leticia Quintanilla-Fend
University of Tuebingen, Germany
The 2008 WHO classification of tumors of hematopoietic and
lymphoid tissues has adopted consensus guidelines for the definition
of well-defined entities. The major principle of the classification is
the recognition of distinct diseases according to a combination of
morphology, immunophenotype, genetic, molecular and clinical
features. These disease entities are stratified according to their cell
lineage and their derivation fromprecursor ormature lymphoid cells.
Although the new 2008 WHO classification intentionally does not
divide lymphomas by grade, traditionally mature B-cell lymphomas
composed mainly of small lymphocytes have been called low-grade
lymphomas. These small B-cell lymphomas include chronic
IAP 2014 ABSTRACTS S21
lymphocytic leukemia/small lymphocytic lymphoma (CLL),
follicular lymphoma (FL), nodal marginal zone lymphoma
(MZL), MALT lymphoma, hairy cell leukemia, and lymphoplas-macytic
lymphoma (LPL).An entity that should be included in the
differential diagnosis of lymphomas composed mainly by small
lymphocytes but with a rather aggressive behaviour is mantle cell
lymphoma (MCL).
As a consequence of new and better available techniques in routine
diagnosis, an increased recognition of early and precursor lesions
of lymphoid neoplasms has emerged. This talk aims to review the
morphological and phenotypic characteristics of the most frequent
small B-cell lymphomas and expand on emerging concepts like,
BCL2 negative FL, grading of FL, Pediatric FL, and indolent and
cyclin D1 negative MCL, differential diagnosis of CD5þ low-grade
lymphomas and more.
Hematopathology: SC14-1
CHALLENGES IN BONE MARROW PATHOLOGY
Robert P. Hasserjian1 and Sa A. Wang2
1Department of Pathology, Massachusetts General Hospital,
Boston, MA, and 2Department of Hematopathology, UT MD
Anderson Cancer Center, Houston, TX, USA
Bone marrow diagnosis presents unique challenges: distinction
between benign and neoplastic conditions may be subtle and the
pathologist must effectively incorporate information from sev-eral
morphologic modalities (trephine biopsy, aspirate smear,
peripheral blood smear) as well as a myriad of ancillary testing
results. In this Short Course, several difficult diagnostic
scenarios will be explored using actual clinical cases that
illustrate key points in the differential diagnosis of bone marrow
diseases. These will include hypocellular bone marrow (in
which distinction between hypoplastic myelodysplastic syn-drome
and aplastic anemia may be difficult), fibrotic bone
marrow, and marrow lymphoid infiltrates, with discussion of
both B-cell and T-cell lymphomas. Hypercellular bone marrow
raises distinct differential diagnoses depending on whether the
patient is cytopenic or presents with elevated counts, and can reflect
a myeloid neoplasm or various reactive conditions in either situation.
An accurate diagnosis relies on understanding the spectrum of
diseases that can produce specific patterns in the bone marrow
and awareness of clues that help distinguish among the differential
diagnostic possibilities. Depending on the clinical context, the
pathology may variably weigh morphology, clinical information,
and ancillary test results in arriving at the final diagnosis.
Hematopathology: SS14-1
T AND NK CELL NEOPLASMS, LESSONS FOR THE
WORLD FROM ASIA
Shigeo Nakamura
Nagoya University Hospital, Nagoya, Japan
The WHO classification of lymphoid neoplasms was published
in 2001, then was updated in 2008, and will be evolving in the
future. This classification is based on the disease discovery and
accurate description by pathologists beyond the heterogeneity in
the geographical distribution of the disease entities. It is now
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