|Year : 2015 | Volume
| Issue : 2 | Page : 48-52
Diagnostic role of ultra sound and computed tomography guided fine-needle aspiration cytology and Tru-cut biopsy experienced in 50 adult patients of mediastinal diseases
Dibyendu Saha1, Jaydip Deb2
1 Department of Pulmonary Medicine, K.P.C. Medical College and Hospital, Kolkata, West Bengal, India
2 Department of Pulmonary Medicine, Bankura Sammilani Medical College and Hospital, Bankura, West Bengal, India
|Date of Web Publication||16-Jun-2015|
Flat-202, A-10, Sugam Park, Kolkata - 700 103, West Bengal
Source of Support: None, Conflict of Interest: None
Context: Etiology and clinical spectrum of mediastinal diseases are very wide. Clinico-radiological pattern of mediastinal diseases depends on the size, location and etiology. Hence, noninvasive approach to these cases sometimes leads to diagnostic dilemma. Aims: We performed a prospective study over a 1-year period with the objective of evaluation of diagnostic yields and risk of trans thoracic ultra sound (TTUS) and computed tomography (CT) guided fine-needle aspiration cytology (FNAC) and Tru-cut biopsy along with comparison of cost-effectiveness among mediastinal diseases where clinical and noninvasive imaging could not conclude the diagnosis. Materials and Methods: A prospective study of mediastinal diseases of the adult population without having any diagnosis admitted in a tertiary care hospital in Eastern India was performed after clearance of the ethical committee of the institute. Fifty cases of mediastinal diseases were seen during the study period. One patient sometimes had undergone more than one procedure. The choice of a procedure depended upon the location of the lesion, need of further detail and patient's financial status. During the calculation of diagnostic yield of procedure, conclusive results and concordant results to more invasive procedures were considered. Statistical Analysis Used: Statistical analysis was performed using MedCalc ® Version 184.108.40.206 for analysis of data. Results: Among 50 patients TTUS guided FNAC were conducted in 26 (52%) occasions and CT guided FNAC were conducted in 26 (52%) occasions. TTUS guided Tru-cut biopsy were done in eight cases (16%), and CT guided Tru-cut biopsy were done in 32 cases (64%). CT guided Tru-cut biopsy had higher diagnostic yield (96.87%) than TTUS guided Tru-cut biopsy (75%). TTUS guided, and CT guided procedures had similar complication rates. Conclusion: Tru-cut biopsy if applicable is much superior to FNAC for a definite diagnosis of the mediastinal diseases. TTUS guided invasive procedures are very much cost-effective and comparable with CT guided invasive procedures in respect to risk and diagnostic yields.
Keywords: Computed tomography guided invasive procedure, fine needle aspiration, mediastinal diseases, transthoracic ultrasound, Tru-cut biopsy, ultrasound guided invasive procedure
|How to cite this article:|
Saha D, Deb J. Diagnostic role of ultra sound and computed tomography guided fine-needle aspiration cytology and Tru-cut biopsy experienced in 50 adult patients of mediastinal diseases. J Assoc Chest Physicians 2015;3:48-52
|How to cite this URL:|
Saha D, Deb J. Diagnostic role of ultra sound and computed tomography guided fine-needle aspiration cytology and Tru-cut biopsy experienced in 50 adult patients of mediastinal diseases. J Assoc Chest Physicians [serial online] 2015 [cited 2021 Mar 2];3:48-52. Available from: https://www.jacpjournal.org/text.asp?2015/3/2/48/158850
| Introduction|| |
Interest in the mediastinum is due to the diversity of the various structures it contains and the multiplicity of disease processes by which it can be affected. Most of these diseases have nonspecific clinical manifestation, which results in considerable challenges for clinical diagnosis. In addition, its relative inaccessibility for diagnostic examination result in considerable challenges to the clinician for evaluation of mediastinal diseases.  The diagnostic evaluation of the mediastinal disorders can be divided into two phases: Noninvasive investigations like imaging and invasive procedures to obtain tissue samples. Among the invasive procedures trans thoracic ultra sound (TTUS) guided and computed tomography (CT) guided fine needle aspiration cytology (FNAC), and Tru-cut biopsy are not new. ,, TTUS guided procedures are very much cost-effective in a low cost set up like ours and TTUS guided procedures are very much helpful for superior and anterior mediastinal disease evaluation.  Against this background, the present study was conducted to compare diagnostic yields, complication rates and cost-effectiveness of those invasive procedures.
| Materials and Methods|| |
This study was a prospective analysis of adult cases of mediastinal diseases without having any diagnosis after clinical and noninvasive radiological evaluation, admitted in the department of pulmonary medicine of a tertiary care teaching hospital in Eastern India over a period of 12 months (April 2010-March 2011).
Patients of any type of mediastinal diseases detected clinically and or radio logically of both genders of the adult population whose definitive diagnosis could not be made after clinical and noninvasive imaging. Written informed consent was taken from all patients, and the study was cleared by the Ethical Committee of the institute.
(1) Age < 15 years, (2) bleeding disorders, (3) very poor general condition (4) cases of intra-bronchial growths mimicking mediastinal lesion revealed by fiber optic bronchoscopy (FOB).
Detailed previous radiological evaluations were studied in all patients fulfilling the case definition. FOB was performed in all cases to exclude any intra-bronchial growth mimicking mediastinal lesion. Ultra sound (USG) and CT guided FNA were maximally employed in the study considering low risk and low cost of the procedure. Thin caliber (20-25 gauge) LP needles were used to obtain specimens for cytological evaluation. Mediastinal lesions, which were touching or near the chest wall were also selected for Tru-cut biopsy in the same occasion considering detailed and definite result. In addition, cases with inconclusive results from FNAC were all put for Tru-cut biopsy. Under image guidance after determination of the specific area of interest Tru-cut biopsy were done. Two types of Tru-cut biopsy needles were used, one is manually operated Shoney Cut Biopsy needle (16 g × 4.5 cannula) with 20 mm specimen notch and other one is automated Tru-cut biopsy needle named as automated spring loaded biopsy gun machine. After Tru-cut biopsy impression smears were prepared first from obtained material and the specimen was collected for histopathology and immunohistochemistry if necessary.
During the consideration of modes of image guidance, TTUS is preferred first due to its low cost wherever it is helpful considering different topographical distribution of mediastinal lesions. For anterior mediastinal lesions anterior parasternal and suprasternal approaches, for posterior mediastinal lesions paravertebral approach and for middle mediastinal lesions right and left anterior parasternal approaches were applied. Few large masses were approached in TTUS through intercostals spaces. Inconclusive and unapproachable cases by TTUS guided invasive methods were kept for CT guided invasive procedures. Only conclusive results and concordant reports to more sensitive investigations were considered during the evaluation of diagnostic yield of a test in this regard. Postprocedure observation was done in all cases keeping resuscitation kit and the emergency service ready at hand.
All cases were followed-up and cytopathological and histopathological reports were studied. Outcome was defined as one of the following.
A definitive diagnosis is made; hence proper therapeutic management can be made.
A definitive diagnosis is not possible (1) Due to poor qualitative and or quantitative sample (2) nonspecific cytological or histopathological features leading to in conclusion to draw a diagnosis.
High proportion of agreement is present between results of initial and subsequent test where initial result is hinting correctly the result of the subsequent test.
All the available information was recorded meticulously, and a database was created. A grand chart was prepared, and statistical analysis was performed using MedCalc ® Version 220.127.116.11 for analysis of data.
| Results|| |
A total of 50 patients fulfilling case definition were studied in the study period. Many of the patients had undergone more than one invasive procedure. In some cases, one procedure gave the evidence of presence of disease without any confirmation of specific disease. In those situations, other procedures were implicated for knowing histopathological details and immunohistochemistry of the lesion as needed. Total number of procedures was 92. During the calculation of diagnostic yield of a particular procedure, conclusive results and concordant results to higher procedures were considered.
Of 50 patients undergone invasive procedures [Table 1], TTUS guided FNAs were conducted among 26 patients (52%) with conclusive and or concordant results coming from 17 (65.38%) of them. So diagnostic yield of TTUS guided FNAC was 65.38%. Similarly, CT guided FNA was performed among 26 patients (52%) with high (84.61%) diagnostic yield. Eight cases (16%) undergone TTUS guided Tru-cut biopsy of mediastinal lesion and 6 (75%) out of them were conclusively diagnosed making diagnostic yield of 75%. CT guided Tru-cut biopsy was performed among 32 cases (64%) resulting a very high diagnostic yield (96.87%) [Table 1]. Of 50 patients, FNAC were considered in 52 occasions. Two patients were undergone both TTUS and CT guided FNAC. Among 52 occasions of FNAC conclusive and or concordant results were made in 39 resulting diagnostic yield of 75% among image-guided FNAC procedure. Similarly, Tru-cut biopsy was done in 40 occasions resulting conclusive result in 37 occasions making a diagnostic yield of 92.5%. As a whole TTUS guided invasive procedure and Thoracic CT guided invasive procedure had a diagnostic yield of 67.64% (23 conclusive and or concordant result out of 34 tests) and 91.37% (53 conclusive and or concordant result out of 58 tests) respectively.
A 50 patients fulfilling case definition had undergone total 92 invasive procedures. Among the procedures [Table 2] TTUS guided FNAC was done in 26 cases, and complication occurred on three occasions (11.53%). Similarly, in eight cases TTUS guided Tru-cut biopsy was done and complication occurred only once, making 12.5% complication rate of the procedure. Complications occurred once in 26 occasions of CT guided FNAC making complication rate of 3.84%, which is the least among all complication rates of the invasive procedures done in the study. CT guided Tru-cut biopsy were done 32 times, and complication occurred 4 times making the complication rate of 12.5%.
Cost, yield and complication comparison of different invasive procedures
Transthoracic ultrasound guided procedures were less costly than CT guided procedures [Table 3]. Average cost of TTUS guided FNAC and Tru-cut biopsy procedures were Rs. 250-500 and Rs. 1000-1200, respectively. Cost of CT guided FNAC was approximately Rs. 1250-1500 and that of CT guided Tru-cut biopsy was Rs. 2000-2500. TTUS guided FNAC, and Tru-cut biopsy were of low cost. Diagnostic yields of FNAC and Tru-cut biopsy were higher than same ones when done under TTUS guidance. Complication was least in CT guided FNAC (3.84%) and highest in Tru-cut biopsy when done under TTUS and or CT guidance (12.5% in each).
|Table 3: Cost, yield and complication comparison of different invasive procedures (n=92)|
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| Discussion|| |
Study of cell or tissue obtained from many kinds of procedures is very much important for exact diagnosis of mediastinal masses.  It is again reflected in the present study by the number of cases enrolled (50 over a 1-year period). Hence, it is obvious that invasive procedures are very necessary for diagnosis of mediastinal diseases. Among the invasive procedures TTUS and Thoracic CT guided FNAC and Tru-cut biopsy were studied thoroughly in the present study. Only conclusive results and concordant reports to more sensitive investigations were considered during the evaluation of diagnostic yield of a test. In the similar way one study  was done earlier where the diagnostic rates for needle aspiration for cytology and histology was determined by the number of positive or correct diagnoses divided by the total number of patients examined. Diagnostic yield of TTUS guided FNAC was 65.38% in our study. This finding has been supported by Hsu et al. (diagnostic rate of UG-FNA was 52%) and Rubens et al.  (US guided FNAC was 77% sensitive). Another study  in Springfield, USA on diagnostic accuracy of image-guided percutaneous FNA biopsy (FNAB) of the mediastinum also showed a high proportion of agreement (78%) between FNAB and subsequent histological diagnoses for a wide variety of mediastinal lesions. Diagnostic yield of TTUS guided Tru-cut biopsy was 75.0% in our study. A better diagnostic yield was found in the study of Annessi et al. (USG guided biopsy of anterior mediastinal masses among 42 patients showed accurate diagnosis in 100% cases) as that study concentrated only in anterior mediastinal cases, which are easy to approach by TTUS. In our study, diagnostic yield of thoracic CT guided FNAC, and Tru-cut biopsy were 84.61% and 96.87%, respectively. Similarly, Deb et al. in their study got a very high result before done on trans thoracic cutting needle biopsy where all the cases of intrathoracic mass lesion touching the chest wall were selected for Tru-cut biopsy and diagnostic yield was 97.95%. From the present study and different other studies, it is clear that image-guided procedures are quite helpful to produce good diagnostic yield of FNA and Tru-cut biopsy of mediastinal masses. In the present study, diagnostic yield of TTUS guided procedure was a bit low (comparable with study of Hsu et al. ) due to a small number of TTUS guided procedures. TTUS guided FNAC and Tru-cut biopsies were seen to be more successful among the antero-superior mediastinal lesions and large mediastinal masses reaching peripheral areas of thorax. However, Thoracic CT guided procedure showed a very high diagnostic yield. As a whole TTUS guided invasive procedure, and thoracic CT guided invasive procedure had a diagnostic yield of 67.74% and 91.37% respectively.
Present study showed complication rate of TTUS guided FNAC and Tru-cut biopsy are 11.53% and 12.5%, respectively. CT guided Tru-cut biopsy had 12.5% complication rate. However, CT guided FNAC made least complication (3.84%). The incidence of complications in this study is very small and compares favorably with several previously published series, ,,,,, where the rate varied from 11% to 24%.
Cost, yield and complication comparison in our study revealed that in a low cot set up TTUS guided invasive procedures are very much cost-effective and as comparable as costly CT guided invasive procedures when question of diagnostic yield and complication of procedure comes.
| Conclusion|| |
Tru-cut biopsy procedure if applicable is much superior to FNAC procedure for definite diagnosis of the mediastinal diseases. USG guided invasive procedures are very much cost-effective and have the advantage of real time guidance. It is also very much comparable with CT guided procedures in respect to risk and diagnostic yields, when performed by radiologist experienced in thoracic USG.
| Acknowledgment|| |
Dr. S. Chattopadhyay, Department of Radio-diagnosis R. G. Kar Medical College, Kolkata, West Bengal, India.
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[Table 1], [Table 2], [Table 3]