# Extranodal NK/T-Cell Lymphoma without Nasal Cavity Involvement Associated with Epstein-Barr Virus: A Multimodality-Based Diagnosis of Two  Cases

Authors: Fernando Cobo; Clara Chamorro; Francisco Ramos; Ángel Concha
Journal: Scholarly Research Exchange
 (2009)

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## Abstract

We report two cases of extranodal NK/T-cell lymphoma, nasal type, in immunocompetent patients without nasal cavity involvement. In the two cases, the initial presumptive diagnosis was tuberculosis and there was a rapid dissemination of the tumor with short survival after the hospital admittance. An autopsy was performed showing infiltration in several organs including lymph nodes and mesenteric and retroperitoneal fat. Histological sections showed an angiocentric and angiodestructive growth pattern and the immunophenotype was CD45+, CD3+ (cytoplasmic), as well as Granzyme B+ and EBV+. However, CD56 expression was only positive in a case in which the molecular study showed T-cell gene rearrangement with monoclonal appearance and associated with hemophagocytic syndrome. These cases represent rare examples of NK/T-cell lymphoma disseminated outside the nasal cavity highly aggressive that lead to the rapid death of the patients.


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## Body

## 1. Introduction

Extranodal
NK/T-cell lymphomas are a group of neoplasias characterized by a broad
morphologic spectrum. These tumors mainly show an extranodal presentation such
as nasal cavity and nasopharynx, but may have other sites of involvement.
Extranodal NK/T-cell lymphomas occur most commonly in South East Asia and South America and are rare elsewhere [1].These lymphomas are
more frequent in immunocompetent patients though have also been described in
immunosuppressed patients [2, 3]. The etiology of this kind of lymphoma is
unknown but NK/T-cell lymphomas of nasal type are constantly associated with
EBV irrespective of the geographic origin [1]; although EBV has a special
tropism with B-cell type, this virus can infect T and NK cells and this
infection leads to a higher risk of lymphoma [4]. Although in Asian
populations the association of NK/T-cell lymphomas extending outside the nasal
cavity with EBV is strong, this association seems less clear in white
populations [1]. EBV probably has an oncogenic role in these lymphomas but the
mechanisms by which EBV can produce the cell transformation or gain entry into
tumor cells of NK/T-cell lymphomas are unknown.The histological
features of these tumors are often a diffuse angiocentric infiltrate, with
necrosis and vascular destruction [1]; however, these histological
characteristics might be seen in other types of lymphoma [5]. Characteristically,
NK/T-cell lymphomas express CD2, CD56, and intracellular CD3ε, and might
produce cytotoxins perforin, granzyme B, or TIA-1 [6], but there are cases with
CD56-cytotoxic T-cell phenotype [1]. The clinical features are those related
with the affected organ, but the disease might quickly disseminate to several
locations such as gastrointestinal tract and skin, and in some cases, may be
complicated by a hemophagocytic syndrome [7, 8].The detection of
monoclonal expansion of the TCRγ chain genes can be an important supplement
for the diagnosis of NK/T-cell lymphomas. In the nasal type, NK/T-cell lymphoma
clonal T-cell receptor gene rearrangement has been reported in several cases
with molecular methods obtaining different detection rates [9].In this
manuscript, we have described two recent cases of extranodal NK/T-cell lymphoma
in white patients without nasal cavity involvement, EBV+, dissemination to
several organs with important infiltration of mesenteric-intraperitoneal fat
tissue, quick fatal progression, and presumptive clinical diagnosis of tuberculosis.
The final diagnosis of these cases was performed by means of
multiple approaches correlating clinical and morphological, immunophenotypic, molecular data from the
autopsy.


## 2. Case Reports

Case 1.
A 61-year-old
Spanish man was admitted to hospital due to the presence of fever with
pancytopenia 5 months before this visit. The patient had been diagnosed with diabetes
mellitus type 2 eight years ago. At presentation, his temperature was 39.5°C, blood
pressure was 90/55 mmHg and pulse was 108/min. Physical examination showed
hepatosplenomegaly and the rest of the physical examination was unremarkable.
The initial presumptive diagnosis was an infection (e.g., disseminated
tuberculosis) or neoplasia because the Ca 19.9 level was elevated. A thoracoabdominal
CT scan was performed and showed hepatomegaly, ascitic fluid, and bilateral
pleural effusion. A bone marrow biopsy was also carried out showing presence of
haemophagocytic histiocytes infiltration. Serologies for HBV, HCV, HIV, CMV, EBV, Leishmania,
and Toxoplasmosis were carried out but were normal.
On day 15 of the
admittance, the patient developed progressive dyspnea and multiorgan failure leading
to death. An autopsy was later performed. The main macroscopic findings were several
necrotic-hemorrhagic nodules in the mesenteric-intraperitoneal fat (Figure1(a))
and multiple necrotic foci in lung, liver, kidney, and suprarenal (Figure 1(b)). Congestive
lung parenchyma with the presence of pleural effusion as well as the presence
of pericardial effusion also was observed. Hepatomegaly with ascitic fluid in peritoneal cavity and congestive
splenic parenchyma was discovered. The rest of the organs were normal,
including the brain and the nasal cavity.
Multiple samples
of tissues from all
these organs were taken and histological sections were stained with hematoxylin
eosin and also immunostains were carried out for different primary antibodies for immunophenotyping the
cellular infiltrate. The microscopic study showed liver, spleen, lung, pancreas,
bone marrow, and suprarenal infiltration by a lymphoproliferative infiltrate, as
well as signs of haemophagocytic syndrome. The infiltrate was predominantly angiocentric,
with necrosis and vascular destruction (Figures1(c) and 1(d)).
The
immunochemical study was performed using reagents and materials provided by
Dako Diagnostic (Carpinteria, Calif, USA) and Novocastra (Newcastle, UK) and
used following the manufacturer's recommended specifications and by means of
the automatic immunostainer Horizon (Dako Diagnostic, Glostrup,
Denmark).
The
immunophenotype of this tumor was CD45+, CD2+, CD3ε+, CD56+ (Figure 1(e)), Granzyme
B+ and TIA+ (Figure 1(f)), as well as CD20−, CD79a−, CD43− and CD45Ro−. The
abundant histiocytic infiltrate was CD68+.
A PCR study for
EBV viral genome of Bam-HI-W system was performed and the result was positive.
This was also corroborated by the LMP1 immunochemistry for EBV.
Finally, a
multiplex real-time PCR study for T-cell gene rearrangement was performed on
DNA extracted from the paraffin block. A capillary electrophoresis in
polyacrylamide gel by means of the ABI-PRISM 310 genetic analyzer (Applied
Biosystems, foster City, Calif, USA) was carried out. This study showed T-cell
gene rearrangement with monoclonal appearance.(Case1).
(a)
An image showing
abundant necrotic-hemorrhagic nodules corresponding to
mesenteric-retroperitoneal fat tissue (see the red arrows)(b)
A photograph showing the
important suprarenal infiltration for the lymphomatous cells (see the red
arrows)(c)
Polymorphous lymphocytic
infiltrate of fat tissue with atypical elements(d)
Fibrinoid changes in
vascular walls and abundant necrotic cellular debris. Note the isolated
pleomorphic nuclei of neoplastic cells(e)
Expression of the CD56
marker in the malignant cells(f)
The neoplastic cells also show
TIA expression in the malignant cellsCase 2.
A 46-year-old
Spanish man was diagnosed with ulcerative colitis in 2003, and with treatment
with azathioprine (200 mg/day) since February 2005. In December 2006, the
patient was admitted to hospital due to the presence of arthralgias and fever. The
physical examination was unremarkable and treatment with prednisone was
started. A few days later, the patient had general disturbance with neurological
symptomatology (facial paralysis, loss of strength) and loss of consciousness.
A brain CT scan was performed showing images that could seem a
meningoencephalitis of probable tuberculous or cryptoccocal etiology. The
cerebrospinal fluid analysis showed an elevation of the pressure and the
leucocytes (80% lymphocytes). The rest of the studies were unremarkable. A
treatment with antituberculous, antifungal, and antibiotic drugs began, but the
symptoms did not remit, and in February 2007, the patient died. An autopsy was also
performed. As in Case1, the main macroscopic findings were
necrotic-hemorrhagic nodules of the mesenteric-intraperitoneal fat tissue (Figure 2(a)). Other findings were as follows: plentiful pleural effusion with turbidity,
several pleuro-pleural adherences, and acute haemorrhagic congestive of both
lungs; plentiful ascitic fluid with turbidity, with several peritoneal-mesenteric
adherences and multiple enlarged mesenteric, peripancreatic and paraaortic lymph
nodes; hepatomegaly with necrotic nodular parenchymal lesion of 1 cm; colonic mucosa with multiple ulcerative
lesions and multiple mesenteric adenopathies; heart appearing with thickness of
perimiocardium and important infiltration of the fat (Figure 2(b)); both kidneys
had multiple cortical necrotic lesions; as well as a cerebrospinal fluid with
turbidity and thick meninges were observed. There was no malignant infiltration
in the nasal cavity. A histological examination was performed and microscopic
slides of all organs were stained with hematoxylin eosin and also immunostains
were carried out for different primary antibodies to immunophenotype the
cellular infiltrate. The meninges’ alteration was induced by unspecific inflammation
but there was no evidence of neoplastic infiltration. The microscopic
examination showed renal, liver, and intestinal infiltrations as well as evidence
of mesenteric-intraperitoneal fat infiltration by neoplastic cells (Figures 2(c) and 2(d)).
The
immunochemical study was performed using reagents and materials provided by
Dako Diagnostic (Carpinteria, Calif, USA) and Novocastra (Newcastle, UK) and
used following the manufacturer`s recommended specifications and by means of
the automatic immunostainer Horizon (Dako Diagnostic).
The
immunophenotype of this tumor was CD45+, CD2+, CD3ε+, granzyme B (Figure 2(e)), and
CD56−, CD20−, CD4−, CD8−, CD72a−. EBER-EBV in situ hybridization was also
positive (Figure 2(f)) as well as LMP-1 immunochemistry for EBV (figure not
shown).(Case2).
(a)
An image showing abundant necrotic-hemorrhagic nodules
corresponding to the mesenteric fat tissue with enlargement of lymph nodes (see
the red arrows)(b)
Macroscopic heart
infiltration visualized as white indurate nodules more evident in the
pericardium fat and in the superficial ventricular myocardium (see the red
arrows)(c)
Diffused infiltration of fat
tissue by atypical lymphocytes(d)
High magnification of
polymorphic cellular population with occasional pleomorphic nuclei(e)
There is a
cytoplasmic-granular positivity in the malignant cells for granzyme B
(cytotoxic molecules)(f)
The EBER-EBV in situ
hybridization appears positive in numerous tumoral cells


## 3. Discussion

Extranodal
NK/T-cell lymphoma, nasal type, is a lymphoproliferative disorder
characterized, in the majority of cases, by an angiocentric infiltrate with vascular
destruction and necrosis [1]. In these kinds of lymphomas, the etiology is
still unkown, but they are always associated with EBV, irrespective of the
geographic origin [1]. These tumors are more frequent in Asian and South
American populations and are rare in Western countries; however, in our
hospital, we have recently diagnosed three cases, two of them are described in
this report and the other has already been published [3].The most common
location of NK/T-cell lymphoma is the nasal cavity although some cases might be located in other places and lymph nodes also might be infiltrated. Curiously, in our cases, the
most important affectation was observed in lymph nodes and in retroperitoneal
and mesentery fat tissue as well as abdominal organs. In both cases, massive
infiltration of retroperitoneal fat tissue and mesentery with pancreatic
involvement was demonstrated.Another important
unexpected fact is that in our two cases there was no nasal cavity affectation like
in the case we recently published [3]. For this reason, we can speculate the possibility of less nasal cavity affectation and more abdominal involvement in extranodal
NK/T-cell lymphomas originated from patients in western countries.On the other
hand, a few reports have shown the association of extranodal NK/T-cell lymphoma
with haemophagocytic syndrome [7, 8]. This complication is characterized by the
presence of fever, pancytopenia, and hemophagocytic histiocytes in bone marrow.
In Case 1, a hemophagocytic syndrome and bone marrow affectation could be seen.At present, the
diagnosis of these kinds of lymphomas is made with greater precision by using
immunophenotyping [6]. Extranodal NK/T-cell lymphoma characteristically express
T-cell marker CD2, NK cell marker CD56, and lack surface CD3 expression (but
express intracellular CD3ε). Also, this tumor may produce cytotoxins perforin, granzyme
B, and TIA-1. However, NK/T-cell lymphoma with CD56 expression represents the
most common immunophenotype among these tumors [8]. However, several studies
have demonstrated that CD3ε+, CD56−, EBV+, and cytotoxic molecule  +  cases can
be also nasal type NK/T-cell lymphomas because these cases show a similar
clinical course as in cases with CD56 expression. This marker, although it is
highly useful for these lymphomas, is not specific and can be expressed in other
peripheral T-cell lymphomas that express the γδ T-cell receptor. Moreover, this
diagnosis should not be made in the absence of cytotoxic molecule expression or
EBV positivity. In this report, a case with CD56 expression (Case 1) and other
CD56− (Case 2) could be seen; both cases are EBV+ and granzyme B+, thus the phenotype
was concordant with these criteria.NK/T-cell
lymphomas may disseminate quickly to several organs and the symptomatology will
depend on the site of involvement. In patients with rapid dissemination and
affectation outside the nasal cavity, this tumor is highly aggressive, with
short survival times and poor response to therapy, as occurred in our cases. In
these situations, in order to carry out a final and precise diagnosis and to
improve the knowledge of true incidence and clinical symptomatology, an autopsy
is necessary. The lymphomatous infiltrate in several organs might show an
angiocentric and angiodestructive growth pattern. Also, extensive necrosis and
vascular destruction are very common. In these cases, the differential
diagnosis should be established with necrotizing granulomatous lesions such as
tuberculosis and aspergillosis, with pancreatitis/penniculitis, vasculitis and
histiocytosis, and finally with other kinds of lymphomas such as angiocentric, high-degree
extranodal lymphomas, as well as NK/T panniculitis-like lymphomas. In Case1,
we also carried out the differential diagnosis with nontumoral lesions such as
necrotizing pancreatitis and with tumoral lesions like pancreatic
adenocarcinomas due to the high level of Ca 19.9 and the ductus pancreatic distortion
by necrotic and inflammatory lesions. Curiously, in our two cases, the initial
presumptive diagnosis was tuberculosis.To conclude,
NK/T-cell lymphomas are tumors mainly caused in Asian and South American
countries, but can also be produced in the Western population. These tumors
mainly involve the nasal cavity although in some cases this area cannot be
involved, as in our reports, so it is necessary to keep in mind this fact in
order to suspect the diagnosis. Several cases can disseminate outside the nasal
cavity and multiple organs could be infiltrated; these cases are more
aggressive than those localized in the nose and the response to treatment is
poor. The mortality is high in these lymphomas and an autopsy could be
necessary to carry out the correct diagnosis. This usually requires a
multimodality approach correlating clinical, morphological, inmmunophenotypic,
and molecular data.



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*Source: 963781-2009-02-25.xml*