59 / 366
L. Burbat
*
, C. Mangano, R. Lanzellotto, E. Petrini, C. Forcato, F.
Fontana, N. Manaresi, B. Hirsch, M. Hummel
*
Charité, Pathology, Berlin, Germany
Objective:
Classic Hodgkin
’
s lymphoma (cHL) is characterized by the pres-
ence of CD30-positive and morphologically distinct
—
often multinucleat-
ed
—
tumour cells, the so-called Hodgkin (H) and Reed Sternberg (RS) cells.
A unique feature of cHL is the low tumour cellularity, comprising up to 5 %
of all cells. In the present work we demonstrate the purification of HRS cells
from FFPE tissue sections using the DEPArray
™
technology.
Method:
FFPE tissue sections were disaggregated to a single cell suspension
and stained for CD30 (BerH2) and DAPI. By DEPArrayTM technology,
CD30-positive HRS cells were selected and morphologically evaluated.
Then, pools of HRS cells and lymphocytes were recovered consecutively
and whole genome amplified. Ultimately Ampli1
™
LowPass sequencing
kit was used to assess genome-wide copy-number aberrations (CNA).
Results:
CNA profiles enabled a distinct discrimination of malignant
HRS cells from non-malignant lymphocytes: HRS cells exhibited an
aberrant CNA profile with multiple gains and losses, while lymphocyte
pools showed a generally flat profile.
Conclusion:
The automated, image-based DEPArray
™
sorting technol-
ogy enables the precise selection and isolation of rare HRS cells from
FFPE cHL-derived samples as demonstrated by the aberrant CNA pro-
files of the purified HRS cells.
OFP-14-012
Type-I Interferon signature in cutaneous blastic plasmacytoid den-
dritic cell neoplasm
L. Lorenzi
*
, D. Vairo, S. Fisogni, S. Lonardi, M. Bugatti, S. Licini, S.
Giliani, F. Facchetti
*
University of Brescia, Pathology Unit-DMMT, Italy
Objective:
Expression of type I Interferon (IFN-I)-induced genes in cu-
taneous Blastic Plasmacytoid Dendritic Cell Neoplasm (cBPDCN).
Method:
Skin biopsies of 19 cBPDCN, 5 acute myeloid leukemia
(cAML), 28 Lupus Erythematosus (cLE) and 7 normal skin (NS) were
used. Immunohistochemistry (IHC) for MXA and phosphorilated STAT1
(p-STAT1) were performed on all samples. RNA was extracted from
FFPE sections of 5 cBPDCN, 5 cAML, 4 cLE and 4 NS cases. qRT-
PCR was performed for RSAD2, STAT1, SIGLEC1, IFIT1, MXA and
IFI27 genes to calculate the Interferon Score (IFN-S)(Rice et al., 2013).
Results:
All cLE showed diffuse expression of MXA and pSTAT1 on in-
flammatory infiltrate and keratinocytes. In 18/19 cBPDCN cases MXA was
positive on tumour cells, while its expression in keratinocytes was observed in
6/18, similarly to pSTAT1. MXA and pSTAT1 were negative in cAML and
NS. IFN-S was positive (186.137) in all cLE and negative (17.531) in
cBPDCN. Interestingly, samples withMXA+ keratinocytes had higher expres-
sion of MXA, but not of other genes. Moreover, cAML did not express MXA,
but RSAD2, STAT1, SIGLEC1 and IFI27 were higher than in cBPDCN.
Conclusion:
Data on IFN-I production by BPDCN are conflicting. This
study shows lack of IFN-S in this tumour and identifies a subgroup of
cases with isolated high MXA expression.
OFP-15-001
Lymphomatosis cerebri: A rare and under-recognised pattern of pri-
mary central nervous system lymphoma
H.-Y. Lee
*
, Y.-H. Ho, T. C. C. Lim, C. S.-Lyn Ding, K.-L. Chuah, W.-M.
Yap, T. Umapathi, J. X. Han, J. P. Rao
*
Tan Tock Seng Hospital, Dept. of Pathology
Objective:
Primary central nervous system (CNS) lymphoma (PCNSL)
is a diffuse large B-cell lymphoma (DLBCL) confined to the CNS in
immunocompetent patients. PCNSL usually forms a mass; biopsy and
histopathological confirmation are necessary for appropriate treatment.
Rarely, PCNSL diffusely infiltrates the CNS, with no discrete mass
(
“
lymphomatosis cerebri
”
). Coupled with corticosteroid effects in a biop-
sy, this presentation may cause diagnostic delay.
Method:
A previously well 21-year-old female presented with progressively
unsteady gait and seizures. Magnetic resonance imaging showed confluent
white matter T2 / FLAIR hyperintensity involving the cerebral hemispheres,
cerebellum and brainstem, consistent with an infective, inflammatory or de-
myelinating process. Following a clinical diagnosis of acute disseminated
encephalomyelitis, methylprednisolone, intravenous immunoglobulin, plas-
mapheresis, and cyclophosphamide were administered without sustained im-
provement. A brain biopsy performed at an external institution 3 months after
presentation showed gliosis and perivascular macrophage infiltrates.
Results:
A second biopsy from the right cerebral hemisphere, performed
in our centre after severe clinical deterioration in the subsequent 4 months,
showed an infiltrative tumour consisting of large pleomorphic lymphoid
cells with the immunoperoxidase staining profile of a DLBCL. The pa-
tient expired 6 weeks later.
Conclusion:
Awareness of lymphomatosis cerebri, and that corticoste-
roids might compromise the diagnostic yield in a biopsy may aid more
timely management.
OFP-15-002
Dual-genotype oligoastrocytoma: An underestimated entity?
V. Barresi
*
, S. Lionti, L. Valori, G. Gallina, M. Caffo, S. Rossi
*
University of Messina, Dept. of Human Pathology, Italy
Objective:
To describe a unique case of dual-genotype oligoastrocytoma
with IDH2 mutation.
Method:
The tumour was resected from the temporal lobe of a 25 year-old
man. The whole surgical specimen was formalin fixed and paraffin embedded
for histological examination with haematoxylin and eosin (H&E) stains and
immunohistochemistry. IDH1 and IDH2 genes sequencing, Telomerase
Reverse Transcriptase (TERT) promoter mutational analysis and 1/19q
Fluorescent In Situ Hybridization (FISH) were performed separately in tu-
mour fragments with different morphology and immuno-phenotype.
Results:
Histological examination showed distinct oligodendroglial and
astrocytic areas. The former retained alpha-thalassaemia/mental retarda-
tion X-linked (ATRX) immuno-expression and had absent staining for
p53, while the latter had ATRX loss and p53 over-expression. Gene
sequencing disclosed IDH2 mutation in both areas, while oligodendrog-
lial, but not astrocytic areas, had 1p/19q codeletion and Telomerase
Reverse Transcriptase (TERT) promoter mutation. Based on those find-
ing,s low grade dual-genotype oligoastrocytoma was diagnosed.
Conclusion:
Identification of dual-genotype oligoastrocytoma might be clin-
ically relevant for prognosis and therapy. The incidence of this entity might be
underestimated due to sampling biases or to the use of immunohistochemistry
and molecular analyses in a limited portion of the tumour. We believe that
further analyses on morphologically heterogeneous diffuse gliomas are war-
ranted before dismissing oligoastrocytoma as a distinct nosological entity.
OFP-15-003
Rhabdoid meningioma: Grading and prognostic significance of this
unusual histotype
V. Barresi
*
, M. Caffo
*
University of Messina, Dept. of Human Pathology, Italy
Objective:
To describe the histopathological features and clinical out-
come of two rhabdoid meningiomas with no histological evidence of
malignancy.
Wednesday, 6 September 2017, 14:00
–
16:00, Emerald Room
OFP-15 Joint Session: Neuropathology / Ophthalmic Pathology
Virchows Arch
(
2017
)
471
(
Suppl 1
):
S1
–
S352
S45