Cardiac allograft rejection typified by lymphocytic infiltrate with associated damage to cardiac myocytes
Allograftvasculopathy:Graft coronary arteriosclerosis, demonstrationg severe diffuse concentric intimal thickening producing critical stenosis. The internal lamina(arrow) and media are intact
Hypertrophy myocarditis:disarray, extreme hypertrophy, branching of myocytes as well as characteristic interstitial fibrosis(collagen is blue in this massontrichome stain).
Hypersensitivity:interstitial inflammatory infiltrate composed largely eosinophils and mononuclear inflammatory infiltrate localised to perivascular and expanded interstitial spaces
GIANT CELL MYOCARDITIS:mononuclear inflammatory infiltrate containing lymphocytes, macrophages, extensve loss of muscle and multinucleated giant cells.
LYMPHOCYTIC MYOCARDITIS:lymphocyte infiltrate with myocyte injury
Chagasdisease:myofibrils distended with trypanosomes(arrow) is present along with inflammation and necrosis of individual myofibrils
A is amyloid n h are myocardial cells
Drug induced myocarditis
An approach to myocardial biopsy interpretation
DR. SAURAV SINGH
The endomyocardial biopsy remains the gold standarad mode of
investigation for diagnosing many primary and secondary
EMB a diagnostic interventional procedure after development
and application of cardiac catheterisation and cardiothoracic
In sophisticated centers, evaluation of cardiomyopathic patients
includes a detailed history and physical examination, coronary
angiography and EMB.
Importance of EMB to clinicians
Differentiating between established dilated cardiomyopathy
with no evidence of myocardial inflammation and active
Cardiac amyloidosis and myocarditis that can be definitely
Used to diagnose specifically various types of myocarditis.
Newer Flexible Bioptomes used due to less complication rates
Commonly used bioptomes are:
Single use 50cm Novatome
Argon endomyocardial biopsy forceps
Bipal 7 bioptome
Fluoroscopy is the standard imaging modality used to guide the
The easily assessable anatomy of venous return to the heart with
peripheral access makes the right ventricle an attractive location
for tissue sampling.
The interventricular septum is the preferred biopsy site due to:
Its thickness compared with the right ventrical wall
Its continuity with the left ventricle
Its location in the natural path of blood flow facilitating vascular
Myocyte disarray is normally encountered in the region of ventricular
apex and its junction with inter-ventricular septum.
Free wall perforation and haemopericardium is a major reason for
avoiding the free ventricular wall for biopsy.
Left ventricular biopsies(LVB)
Performed by needle biopsy at the time of open heart surgery or
via a trans-septal approach
Procedure performed percutaneously through the femoral artery,
retrograde through the aortic valve into the left ventricle.
Disease affecting L.V. walls and L.V. masses are the only
indications for LVB.
Proper tissue procurement and handling are essential for
optimal diagnostic evaluation
Biopsy specimens should be gently extracted from the bioptome
with a needle tip.
10% neutral buffered formalin is needed to diagnose:
Zeus fixative or saline (used primarily for immunofluorescence
studies to evaluate antigen-antibody rejection) can be used to
assess allograft rejection.
Trump’s fixative or 4% glutaraldehyde used for:
Drug induced cardiotoxicity.
Specimen in trump’s fixative or 4% glutaraldehyde can be viewed
with Transmission electron microscopy(TEM) in assessing:
Metabolic/ storage disorders
Light chain deposition disease
Snap freezing tissue is optimal for preserving tissue for
molecular analysis like PCR and real-time PCR in evaluation of
For routine diagnostic evaluation, overnight processing and
parrafin embedding are sufficient.
All of the biopsy pieces should be embedded in the same block.
A minimum of 3-6 slides prepared at 4-5micronM thickness
within the paraffin block.
Multiple paraffin ribbons are placed on each slide.
Routinely stain with hematoxylin and eosin.
For emergent cases, a 90min rapid(ultra) processing cycle is
available, and slides can be prepared within 2-3hrs.
Immunohistochemical, immunofluorescence, and molecular
studies are used for specific studies.
Paraffin section immunohistochemistry is used to evaluate for
infectious endocarditis by CMV, EBV.
In situ hybridization is helpful to demonstrate the presence of
EBV or other viral genome.
For diagnostic EMB, a sample should always be set aside for
transmission electron microscopy(TEM)
The sensitivity of detecting transplant rejection can approach
98% with five adequate biopsy fragments.
The adequacy of tissue fragments is very important for correct
diagnostic accuracy and interpretation.
The greatest limitation to EMB is Sampling error.
TEM(transmission electron microscopy) are indicated for
Infiltrative disorders(such as amyloidosis or glycogen storage
Universal fixative is recommended, although any 2%
glutaraldehyde based fixative is suffice.
Congo red or sulfated Alcian blue stain for amyloid fibrils.
Prussian blue stain for Iron deposition.
Masson’s trichome or Movat pentachrome stains to confirm the
presence of myocyte necrosis or interstitial fibrosis.
Gomori methanamine silver for Fungi
Gram stains for Bacteria(endocarditis)
ROLE OF ARTIFACTS IN EMB
Commonest artifact is contaraction bands in myocyte identical
to linear bands on acute ischaemic necrosis and catecholamine
Intussusception or “telescoping” of small arteries confused with
transplantation-related arteriosclerosis and luminal occlusion by
Accumulation of fresh platelet/ fibrin rich thrombus may be
identified along the endocardial surface of biopsy fragments.
(A) Section showing the typical pattern of myofibre disarray that can be seen at
previous biopsy sites.(B) Biopsy artifact showing intussusception of an intramural
vessel, not evidence of occlusion/vasculitis (arrow)
Ventricular perforation is identified by the prescence of
Other commonest is Crush artifact occur while cutting large
Bioptome-induced tissue distortion or Crush artifact can occur.
(A) Biopsy artefact showing pinching of the sample at the time of procurement
(arrows). Also note the region of fibrosis,represents the site of an earlier biopsy.
(B) Tissue fragment from transplant showing endocardial fibrosis, secondary to a
healed biopsy site (thick arrow). Also note the region of interstitial fibrosis and
mixed inflammatory infiltrate consistent with a “vasopressor effect” and probably
not the site of a healed episode of rejection.
s of EMB:
in the absence
CARDIAC ALLOGRAFT REJECTION: TYPIFIED BY LYMPHOCYTIC INFILTRATE WITH
ASSOCIATED DAMAGE TO CARDIAC MYOCYTES
Graft rejection reaction: (A)Early rejection: Foci of lymphocytic infiltrates. (B)Severe
rejection: Significant lymohoid infiltration and myocyte necrosis
Allograft vasculopathy: Graft coronary arteriosclerosis,shows severe diffuse concentric
intimal thickening. The internal lamina(arrow) and media are intact
EMB provides useful information in the following
Idiopathic hypertrophic cardiomyopathy:
Shows changes : Myofibrils disarray
Fibrous changes in intramyocardiac arteries.
Commonest finding is basophilic degenerationof myocardium
appears as finely granular basophilic.
Hypertrophy myocarditis:disarray, extreme hypertrophy, branching of myocytes as well as
characteristic interstitial fibrosis(collagen is blue in this masson trichome stain).
Idiopathic dilated cardiomyopathy:
Endocardial fibrosis, interstitial fibrosis
Hypertrophy of myocardial fibers
Degenerative changes of myocardial fibers
Leukocytic infiltrates are commonly present
Variable myocyte hypertrophy
In active stage, heavy component of eosinophils is present
In inactive stage, various nonspecific changes are seen
DCM demostrates variable myocyte hypertrophy and interstitial fibrosis(collagen
is highlighted as blue in Masson trichome stain)
Classification of Myocarditis :
Diagnosis of myocarditis requires presence of inflammation
infiltrate and myocyte necrosis or degeneration.
Etiology can be viral, bacterial, fungal, parasitic, collagen
vascular disease, drug and radiation induced or transplant
Infiltrate is of lymphocytic in nature admixed with histiocytes.
Fibrosis if present should be quantified(mild, moderate, severe)
and qualified(interstitial, endocardial replacement)
Lesser degree of necrotizing changes.
When both the myocyte damage and the inflammation persist
on subsequent biopsies.
Resolving or healing myocarditis:
When both the myocyte damage and the inflammation are
substantialy reduced, and resolved or healed.
Giant cell myocarditis:
Characterised by multicentric destruction of the cardiac myocytes by
cytotoxic cells and the multinucleated cells.
Recently described newer form of myocarditis characterised by T
lymphocytes that express the gamma-delta receptor and runs
a fulminant course.
Active disease: Interstitial inflammatory infiltrate
Focal myocyte necrosis.
Diffuse, mononuclear, lymphocytic infiltrate
GIANT CELL MYOCARDITIS: Mononuclear inflammatory infiltrate containing
lymphocytes, macrophages, extensive loss of muscle and multinucleated giant cells.
LYMPHOCYTIC MYOCARDITIS: Lymphocyte infiltrate with myocyte injury
Parasitization of myofibrils by trypanosomes
Inflammatory infiltrate by neutrophils, lymphocytes,
macrophages and occasional eosinophils.
Myofibrils distended with trypanosomes infiltration.
CHAGAS DISEASE: Myofibrils distended with trypanosomes(arrow) is present along with
inflammation and necrosis of individual myofibrils.
It includes various infiltrating conditions like:
Drug induced and radiation induced cardiomyopathies:
Adriamycin shows changes like:
Vacuolisation of cardiac myocytes is the earliest change
Appearance of adria cell(characterised by loss of cross striations
and myofilamentous bundles and basophilic staining)
Inflammation is nil or absent, which differentiates it from other
Changes are diffuse, dose dependent and tend to occur in
FINDINGS AND IMPORTANCE
Surgical pathology report should provide as much as diagnostic
information as possible, it includes:
Number of pieces of myocardium
Appearance of myocyte nuclei(hypertrophied, pkynotic,
attenuated, or atrophic)
Prescence of cytoplasmic pigments
Pattern of necrosis(focal or diffuse)
FINDINGS AND IMPORTANCE
Composition of interstitium(e.g., cellularity, fibrosis, edema,
Prescence of endocardial inflammation
The current complication rate with the intravascular procedure
at specialised centres is less than 1%.
Sampling error( if focal in nature or limited to L.V)
Cardiac perforation(most serious)
Tricuspid valve apparatus damage
Pericardial fibrosis/ Thickening
Air embolism and pneumopericardium
TAKE HOME MESSAGE
The endomyocardial biopsy remains the gold standard mode of
investigation, as there is considerable limitation to non-invasive
EMB is used to follow allograft rejection after heart
EMB is used to diagnose conditions like Cardiomyopathies
EMB is used as a research tool to investigate the natural history
EMB is a safe, simple, and effective interventional procedure
with a very low rate of morbidity and mortality.
Interpretation of EMB specimens requires knowledge of patients
It also requires appropriate understanding of cardiovascular
An approach to endomyocardial biopsy interpretation --
Cunningham et al_ 59 (2) 121 -- Journal of Clinical
Rosai and Ackermann’s
Sternberg surgical pathology