Case Presentation
First Case: A twenty-five-year-old male presented to the emergency
department with lower back pain for three months. It further escalated
leading to progressive weakness of the lower limbs. Magnetic resonance
imaging (MRI) revealed a large dorsal epidural lesion measuring 6cm in
greatest dimension at the level of L4-5 displacing the thecal
sac. There was severe compression of the thecal sac due to the
lesion. According to radiology the differential diagnoses included
hematoma, lymphoma, infected arachnoid cyst, primary neuro-ectodermal
tumor (PNET) and metastasis. Neurosurgery was consulted and the patient
was started on immediate steroid therapy, with dexamethasone 10mg every
six hours to provide immediate relief for the pressure symptoms and
meanwhile the patient was worked up for earliest surgical resection of
the lesion. The patient received three doses of dexamethasone prior to
his surgery.
The surgical specimen revealed diffuse proliferation of lymphoid tissue
with fibrosis and necrosis, on hematoxylin and eosin staining. The
lesion consisted mostly of small lymphocytes with scattered larger cells
and there were numerable apoptotic bodies noted. (Figure 1) The
initial IHC panel showed unusual cytoplasmic granular staining for CD3,
CD19 and CD20, while the controls were unremarkable, making it difficult
to interpret the stains. A more extensive panel, showed CD10, CD21,
CD30, MUM1, MYC, Cyclin D1, LMP1, CD34, CD56, synaptophysin,
chromogranin, ALK1, AE1:3 and TdT to be negative. The large cells
occasionally stained for BCL6, PAX5, P53 and CD79a. BCL2 was positive in
the smaller lymphocytes and very occasionally in the larger cells.
Histologically the lesion was suspicious of a large B-cell lymphoma.
Fluorescence in-situ hybridization (FISH) on formalin-fixed, paraffin
embedded (FFPE) tissue sections revealed polysomy (3-5 copies) of BCL6
(3q27), MYC (8q24), and BCL2 (18q21.3) in 44-55% interphase nuclei.
There was no rearrangement of BCL6, MYC, and BCL2 probes. It was
diagnosed as a lymphoma with over-expression of the MYC, BCL2 and BLC6
proteins which is termed as Double Expressor diffuse large B cell
lymphoma . Modified R-CHOP (rituximab, cyclophosphamide, doxorubicin,
vincristine and prednisone) and intrathecal therapy was initiated for
the patient.
Second case: A fifty-four-year-old woman presented with a neck mass
which had been progressively increasing in size in the past one month.
Computed tomography (CT) scan revealed multiple enlarged lymph nodes in
the neck. The most prominent was a 2.3cm lymph node between the right
jugular vein and carotid artery (Level 3). Patient also had enlarged
lingual tonsils and underwent a laryngoscopic biopsy for the same and
excision of the Level 3 lymph nodes. Patient was administered 4mg
dexamethasone intraoperatively to avoid edema during the procedure. This
information was not conveyed to the pathologists.
The surgical pathology specimen revealed diffuse proliferation of medium
to large pleomorphic lymphoid cells that had completely effaced the
nodal architecture. The atypical lymphoid cells had round to oval nuclei
with vesicular nuclear chromatin, distinct nucleoli, and moderate amount
of cytoplasm. Mitoses and apoptotic bodies were frequently seen and
there were extensive areas of necrosis. CD3 and CD20 were challenging to
interpret due to the similar staining pattern as described in the
previous case. (Figure 2) The IHC panel helped diagnose it as
DLBCL, with positive staining for PAX5, BCL2, BCL6 and rarely p53 and
Ki67 of 60%. The CD10, CD30, MUM1 and MYC were negative in the
neoplastic cells. FISH revealed polysomy of MYC, BCL2 and BLC6 proteins
in 50-60% of interphase nuclei with no rearrangement.
Discussion : DLBCL is the most common and aggressive Non-Hodgkin
B-cell lymphoma, accounting for 30-40% of B-cell lymphoma in the United
States.3 It is a heterogeneous entity with various
forms of clinical presentations and response to treatment. The lymphoma
cells in DLBCL are characteristically large and diffuse in growth
pattern, effacing the normal nodal or extranodal architecture. DLBCL
like all lymphoma work ups starts with B and T cell antibodies (for
example CD3/CD20). The neoplastic cells show positivity for the pan-B
cell markers, CD19, CD20, CD22, PAX5 and OCT2.Pre-diagnosis treatment
such as radiation or steroid is a clinical dilemma.4It might be essential and lifesaving in some situations especially when
there is respiratory compromise due to a lesion or as in the first case
threat of neurological damage.5,6 However the
treatment can have major effect on the antigen expression of lymphomas
and lead to a challenge in diagnosis. The rationale for steroid
administration before biopsy is to reduce tumor burden, thereby
minimizing morbidity and this has particularly discussed in patients
requiring intubation.
Steroid treatment can lead to complete disappearance of the lesion or
may show increased apoptotic bodies and necrosis. Giannini et al. in
their review of primary central nervous system lymphoma (PCNSL)
discussed the various ways in which steroids can impact tumor morphology
ranging from appearance of frequent apoptotic bodies to complete
disappearance which is termed as “vanishing”
lymphoma.7 They have described the presence of
granular CD20 stain in patients who had been treated with steroids.
Interestingly we saw a similar pattern of expression in the initial IHC
stains for CD3, CD19 and CD20. However, without knowing the clinical
management, the staining pattern of CD markers could be misleading or
even lead to a wrong diagnosis. Hence, a thorough clinical history and
seeking information of steroid use is needed in addition to judicious
interpretation of the immunostain. This is strongly encouraged when a
cytoplasmic staining pattern is encountered. Staining for the other
nuclear markers such as PAX5 was interpretable in our cases.
Borenstein et al. have studied the effect of pre-biopsy steroid therapy
in pediatric patients with mediastinal lymphoma. They reported an
adverse effect on the pathological diagnosis in 22% of their
patients.8 They suggest that preoperative steroids
lead to distortion of cellular morphology, compromising accuracy of
diagnosis and more importantly delaying or altering diagnosis and
management plans. In their study the diagnostic accuracy was not
affected for any patients and it was interesting to note that they did
not find any significant difference based on the dose and duration of
steroid used.8 Our 1st patient had
received a higher dose of steroid and for a longer duration as compared
to the 2nd patient. The morphological and IHC impact
was more evident on the 1st case, however it is
noteworthy that an intra-operative administration of steroid also led to
a similar pattern. Two cases are not enough to completely understand the
dose and duration which can impact the cell morphology and antigen
profile, but it may be sooner than expected. The administration of
steroids increased the number of stains required to reach the diagnosis
and led to delays.
Conclusion: These cases highlighted the impact of pre-biopsy
steroid therapy on pathological diagnostic accuracy. As discussed in
previous literature the final diagnosis may not always be affected but
it impacts the patient adversely through delay in reaching the final
diagnosis. Also, for training pathologists it is important to study
controls and know the history before interpreting such cases to avoid
errors which can impact decisions on immunotherapy requiring accurate
information about antigen positivity. However, the administration of
steroid is a clinical necessity in some cases and for these it is
important for pathologists to be aware of these changes which might be
encountered.
References:
1. Swerdlow SH, Campo E, Harris NL, et al. WHO Classification of
Tumours of Haematopoietic and Lymphoid Tissues, Fourth Edition .
2008:439.
2. Swerdlow SH, Campo E, Pileri SA, et al. The 2016 revision of the
World Health Organization classification of lymphoid neoplasms.Blood . 05 2016;127(20):2375-90.
3. Rosenthal A, Younes A. High grade B-cell lymphoma with rearrangements
of MYC and BCL2 and/or BCL6: Double hit and triple hit lymphomas and
double expressing lymphoma. Blood Rev . 03 2017;31(2):37-42.
4. Loeffler JS, Leopold KA, Recht A, Weinstein HJ, Tarbell NJ. Emergency
prebiopsy radiation for mediastinal masses: impact on subsequent
pathologic diagnosis and outcome. J Clin Oncol. 1986 May;4(5):716-21.
5. Pullerits J, Holzman R. Anaesthesia for patients with mediastinal
masses. Can J Anaesth. 1989 Nov;36(6):681–8.
6. Ferrari LR, Bedford RF. General anesthesia prior to treatment of
anterior mediastinal masses in pediatric cancer patients.
Anesthesiology. 1990 Jun;72(6):991-5.
Giannini C, Dogan A, Salomão DR. CNS lymphoma: a practical diagnostic
approach. J Neuropathol Exp Neurol . Jun 2014;73(6):478-94.
7. Giannini C, Dogan A, Salomão DR. CNS lymphoma: a practical diagnostic
approach. J Neuropathol Exp Neurol. Jun 2014;73(6):478-94.
8. Borenstein SH, Gerstle T, Malkin D, Thorner P, Filler RM. The effects
of prebiopsy corticosteroid treatment on the diagnosis of mediastinal
lymphoma. J Pediatr Surg . Jun 2000;35(6):973-6.
Figure 1 : Patient 1. Diffuse proliferation of small lymphocytes
with occasional larger cells (a, Hematoxylin and eosin stain, 100X) with
high nucleus/cytoplasmic ratio and frequent apoptosis (b, Hematoxylin
and eosin stain, 400X). Cytoplasmic staining CD19 (c, 200X), PAX5 (d,
200X), CD79a (e, 200X) and Ki67 (f, 200X).
Figure 2 : Patient 2, Diffuse lymphocytic proliferation (a,
Hematoxylin and eosin stain, 100X and b, Hematoxylin and eosin stain,
200X), CD3 cytoplasmic staining (c, 200X), CD20 cytoplasmic staining
(d, 200X).