INTERVENTIONAL BRONCHOSCOPY

Diagnostic Value of Blood Clot Core During EndobronchialUltrasound-Guided Transbronchial Needle Aspirate

Emily N. Amin • Christopher D. Russell •

Konstantin Shilo • Shaheen Islam • Karen L. Wood

Received: 7 January 2013 / Accepted: 10 March 2013 / Published online: 31 March 2013

� Springer Science+Business Media New York 2013

Abstract

Background Endobronchial ultrasound-guided transbron-

chial needle aspiration (EBUS-TBNA) is being increasingly

used in the sampling of pulmonary masses and mediastinal

lymphadenopathy. The blood clot core (BCC) often obtained

during EBUS-TBNA may not be a true core and therefore

may not be submitted for histological analysis. The fre-

quency in which the blood clot core is positive in patients

with negative cytology undergoing EBUS-TBNA is not

known. The purpose of this study was to evaluate the diag-

nostic role of the blood clot core obtained during EBUS-

TBNA.

Methods An Institutional Review Board-approved retro-

spective chart review was performed from January through

September 2011 for all patients who underwent EBUS-

TBNA at The Ohio State University. The data collection

included cytology and histology results for each procedure.

Blood clot cores obtained from the EBUS-TBNA needle

were sent in formalin for histological examination.

Results Seventy patients underwent EBUS-TBNA and 51

(72.8 %) patients had procedures that yielded a BCC for

histology and aspirate for cytology. Forty-nine percent of

patients with a BCC were diagnosed with malignancy. Of

those with a BCC obtained, five (9.8 %) patients diagnosed

with malignancy were done so based only on the results of

blood clot core alone with negative cytology.

Conclusions Blood clot cores obtained at EBUS-TBNA

contain diagnostic material and should be subjected histo-

pathological examination. When blood clot cores are sent

for analysis, there is the potential to spare up to 10 % of

patients more invasive diagnostic biopsy procedures.

Keywords Endobronchial ultrasound � Transbronchial

needle aspiration � Mediastinal lymph node �Mediastinal staging � Core biopsy

Introduction

Transbronchial needle aspiration (TBNA) is a widely avail-

able diagnostic option to obtain cytologic material from

mediastinal lymph nodes and lung masses. Recently, endo-

bronchial ultrasound-guided TBNA (EBUS-TBNA) has been

increasingly used compared with conventional TBNA for a

variety of indications, including mediastinal staging of lung

cancers [1]. EBUS-TBNA has been shown to have a higher

sensitivity and specificity than conventional TBNA without

ultrasound guidance with only modest increase in duration of

the procedure [2]. The 21- or 22-gauge EBUS-TBNA needles

result in aspiration samples for cytologic examination and

often a blood clot core (BCC) is obtained from the needle

during the procedure when suction is applied. Unlike the core

that can be obtained with the 19-gauge needle used in con-

ventional TBNA, this BCC obtained during EBUS-TBNA

may not represent a true core biopsy specimen. Therefore, it

may not be sent for pathologic examination. In our practice,

we routinely send the BCC when available for pathological

examination in addition to the needle aspiration specimen,

which is examined by a pathologist. The present study was

done to evaluate the diagnostic role of BCC when combined

with cytologic analysis.

E. N. Amin (&) � C. D. Russell � S. Islam � K. L. Wood

Division of Allergy, Pulmonary, Critical Care and Sleep

Medicine, The Ohio State University Medical Center, 201

DHLRI, 473 West 12th Avenue, Columbus, OH 43210, USA

e-mail: emily.amin@osumc.edu

K. Shilo

Department of Pathology, The Ohio State University,

Columbus, OH, USA

123

Lung (2013) 191:305–309

DOI 10.1007/s00408-013-9457-5

Materials and Methods

An Institutional Review Board-approved retrospective chart

review of patients who underwent EBUS-TBNA at our

institution from January through September 2011 was per-

formed. Data, including demographics, cytology, and histo-

pathology results, as well as diagnosis, were recorded for each

patient. All EBUS-TBNA procedures were performed pri-

marily by a pulmonary fellow under the supervision of a

skilled pulmonologist under deep sedation in the bronchos-

copy suite using the same EBUS bronchoscope (BF-UC160F-

0L8, Olympus America, Inc.). The number of passes per sta-

tion was not standardized. The specimen from the EBUS

needle was expelled onto a slide by first replacing the guide-

wire to push any solid material out. Then, a 10-cc syringe was

used to expel the remaining material from the needle onto the

slide and was collected in Roswell Park Memorial Institute

medium (RPMI). Any BCC that was expelled on the slide was

then transferred to 10 % formalin using a blunt needle. Rapid

on-site cytology examination (ROSE) analysis was routinely

performed by a cytotechnician. Cytology smears were stained

with hematoxylin-eosin and Papanicolaou. Cell blocks were

stained with hematoxylin-eosin and when indicated with

immunohistochemical stains.

Results

During the study period, a total of 70 patients underwent

EBUS-TBNA at our institution. Age, sex, and diagnoses are

listed in Table 1. Fifty-one (72.8 %) patients had procedures

that yielded a BCC for histopathologic examination in addi-

tion to cytology. BCC samples (Fig. 1) commonly included

abundant blood components (Fig. 2) admixed with solid

fragments of diagnostic tissue (Fig. 3). Of these 51 patients,

25 (49 %) were diagnosed with malignancy, 8 (15.7 %) had

granulomatous disease, 15 (29.4 %) had benign lymphocytes

on cytology and histology, and 3 (5.9 %) had inadequate

specimens. Of the eight patients with granulomatous disease,

three (37.5 %) were diagnosed with sarcoid, three (37.5 %)

had histoplasmosis, and two (25 %) had granulomas without a

specific diagnosis.

Of the 25 patients diagnosed with malignancy, 15

patients had malignant cells present in both the BCC and

cytology material. These included six with adenocarci-

noma, eight with small cell carcinoma, and one with B-cell

lymphoma. In five patients, only the cytology was positive

for malignancy and the BCC was nondiagnostic. These

included three squamous cell carcinomas and two adeno-

carcinomas. Mutations were obtained from the BCC in six

of the eight patients diagnosed with adenocarcinoma.

The remaining five patients diagnosed with malignancy

had positive BCC with negative or nondiagnostic cytology

results. These included two with squamous cell carcinoma,

one with melanoma, one with B-cell lymphoma, and one

with undifferentiated non-small cell carcinoma (Table 2).

These five patients account for 9.8 % of patients with a

BCC sent for examination. Overall, a diagnosis in 5 of 70

(7.1 %) patients would not have been made if the BCC was

not sent for histology.

The overall diagnostic yield, including a malignancy

diagnosis or granulomas, was obtained in 14 of 19 (73.6 %)

patients if a BCC was not sent and 33 of 51 (64.7 %)

patients if a BCC was evaluated.

Table 1 Characteristics of study population

Patients with BCC

obtained (n = 51)

Patients with BCC not

obtained (n = 19)

Age (year) 15–84 (median 61) 28–87 (median 60)

Sex 51 % male 74 % male

Malignant diagnosis

Adenocarcinoma 8 (16 %) 4 (21 %)

Squamous cell

carcinoma

5 (10 %) 2 (11 %)

Small cell

carcinoma

8 (16 %) 4 (21 %)

NSCLC NOS 1 (2 %) 1 (5 %)

Lymphoma 2 (4 %) 1 (5 %)

Melanoma 1 (2 %) 0 (0 %)

Nonmalignant diagnosis

Sarcoid 3 (6 %) 2 (11 %)

Histoplasmosis 3 (6 %) 0 (0 %)

Granulomas, no

specific

diagnosis

2 (4 %) 0 (0 %)

Benign

lymphocytes

15 (29 %) 4 (21 %)

Inadequate

specimen

3 (6 %) 1 (5 %)

Fig. 1 Gross picture of a BCC obtained during EBUS-TBNA

306 Lung (2013) 191:305–309

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Discussion

EBUS-TBNA has become an important diagnostic proce-

dure in both the interventional pulmonology and thoracic

surgery fields. It has been shown to be a valuable diagnostic

tool for the evaluation of mediastinal lymphadenopathy and

masses. It has been studied most extensively in the role of

mediastinal staging in lung cancer patients. American Col-

lege of Chest Physician (ACCP) guidelines found a com-

bined sensitivity from eight studies of 90 % for EBUS-

TBNA when utilized for staging [1]. These guidelines rec-

ognize EBUS-TBNA as a reasonable modality to stage the

mediastinum in patients with suspected or known non-small

cell lung cancer (NSCLC) with discrete mediastinal lymph

node enlargement or those with central tumors or N1 lymph

nodes. Two studies since the guidelines were published

directly compared EBUS-TBNA and mediastinoscopy and

showed no significant difference between the two procedures

in their ability to stage the mediastinum in patients with

NSCLC [3, 4]. EBUS-TBNA also has been shown to have

good diagnostic yield for benign diseases, including sarcoid

and tuberculosis, especially when combined with other

standard bronchoscopic modalities [5–7].

Given that EBUS-TBNA is a relatively new procedure,

ways to increase its diagnostic accuracy have been and will

continue to be investigated. Although ROSE has been shown

to decrease the number of aspirations needed for diagnosis, it

is not available uniformly [8]. Combination of EBUS-TBNA

with transesophageal ultrasound-guided fine needle aspirate

(EUS-FNA) also has been shown to increase the diagnostic

yield for patients undergoing mediastinal staging for known

or suspected lung cancer [9]. Three studies suggest that

obtaining a core biopsy during the EBUS-TBNA procedure

can increase diagnostic yield [10, 11]. In one study, patients

with metastatic malignancy of unknown primary or patients

with previous extrathoracic malignancy underwent EBUS-

TBNA to evaluate their mediastinal lymphadenopathy.

Tissue cores obtained with the 22-gauge needle were sent for

histology and it was noted that three patients had positive

histology despite negative cytology [10]. Another study

investigated the optimal number of aspirations from each

lymph node station during EBUS-TBNA without ROSE.

This study obtained tissue cores defined as the ‘‘solid sub-

stances in the aspiration needle’’ in the majority of their

aspiration attempts. When tissue cores were obtain in the first

or second aspiration of a lymph node, the sensitivity and

diagnostic accuracy was increased compared with those

without core tissue on the first two passes [11]. In another

study, evaluation of obtaining the ‘‘tissue clot coagulum’’ in

filter paper before placing in formalin for a cell block was

compared with a saline rinse of the coagulum. It was found

that sample adequacy and diagnostic yield was higher in the

‘‘tissue clot coagulum’’ cell block method samples [12].

Our review shows that solid material consisting of BCC

is frequently obtained during EBUS-TBNA procedures

when suction is applied. This is consistent with previous

findings [11]. We sent our BCC tissue in formalin, whereas

others have suggested putting blood clot core material

directly into RPMI for cell block. Our routine clinical

practice includes washing the needle in RPMI, and even

with this practice, the BCC secured the diagnosis in these

additional patients. It is unknown if there is a difference in

diagnostic yield between these two methods and prospec-

tive study is warranted. Although the BCC may not be a

true core biopsy, sending this sample from the EBUS-

TBNA needle for histopathologic evaluation is valuable.

This material can contain diagnostic tissue that in some

cases will be the only specimen that yields a diagnosis. In

Fig. 3 A solid component of the BCC in case 1 represents metastatic

poorly differentiated squamous cell carcinoma (hematoxylin and

eosin stain, 9400, original magnification)

Fig. 2 BCC obtained at EBUS-TBNA of right paratracheal lymph

node in case 1 reveals solid tumor fragments (hematoxylin and eosin

stain, 940, original magnification)

Lung (2013) 191:305–309 307

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our review, almost 10 % of patients (5/51) that had a BCC

sent received a diagnosis of malignancy based on the BCC

alone and were spared further invasive testing. Further-

more, mutations were able to be performed on the BCC in

six of eight patients diagnosed with adenocarcinoma. It is

unknown if these mutations would have been available on

cytology alone without the BCC. Prospective study to

determine if BCC increases the ability to perform muta-

tions would be beneficial. In addition, there are potential

cost savings by avoiding mediastinoscopy in favor of

EBUS-TBNA.

Interestingly, in this small sample we were able to

diagnose lymphoma in two cases. It is believed that his-

topathologic examination is necessary but aspirate when

combined with flow cytometry can yield a conclusive

diagnosis in some cases.

There are limitations to this review that should be noted.

First, it is a retrospective review, which may have limited our

conclusions, because the number of passes, experience of the

operator, and other potential factors were not standardized.

Second, the overall diagnostic yield was not improved by

sending the BCC compared with the group that did not have

the core sent. It may have been that the BCC was less likely to

be sent for formal pathologic examination if ROSE was

positive. This may have decreased the number of BCC

results that we had to review and affected the yield. There

also are occasions that a BCC may not be obtained depending

on the consistency of the lymph node or mass being aspi-

rated. Lastly, negative results were followed clinically in

most cases and were not confirmed with mediastinoscopy so

the sensitive and specificity were not able to be obtained for

this method. Prospective study is needed to eliminate some

of these biases and answer important questions that have

come from this study.

Conclusions

BCC evaluation may provide the only diagnostic tissue

during EBUS-TBNA when cytologic examination is neg-

ative. Given the clinical significance of saving potentially

7.1 % of patients from further invasive testing, the yield of

sending the BCC from each sample seems easily justified.

In addition, there is no increased risk to the patient or

change in procedure required. Therefore, our study adds to

data that suggest that any BCC obtained during EBUS-

TBNA should be sent for evaluation in conjunction with

cytologic examination.

Conflict of interest None.

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