A Study Protocol for Assessing the Correlation of USG Guided Fine Needle Aspiration Cytology and Histopathology of Intra-abdominal Masses

Background: Deeply situated, solitary or nonpalpable lesions of abdomen are a common problem in surgical practice and are generally hard to evaluate. impair the quality of life and may have poor prognosis leading to higher mortalities. By using imaging technique difference between malignant and non-malignant lesions is generally done. USG guided FNAC Expected Results: A significant correlation is expected between histopathology and ultrasound guided fine needle aspiration cytology of intra-abdominal masses. Conclusion: Conclusion will be drawn from on the basis of results obtained from this study.


INTRODUCTION
Deeply situated, solitary or nonpalpable lesions of abdomen are frequently hard to evaluate. For better patient management it is vital to differentiate between non neoplastic and neoplastic lesions and importantly lesions with inflammatory aetiology. By using imaging technique difference between malignant and non-malignant lesions is generally done. With the increasing use of radiological techniques identification of relatively small lesions can be achieved with consistent targeting, but the diagnosis is mainly reliant on obtaining precise tissue specimen collection, which is often done by transcutaneous tissue aspiration [1].
Cytopathology is a major diagnostic technique and there has been an increase in the number of FNACs performed during the last 15 years, since it was first instituted by Martin and Ellis in 1930 [2]. FNAC under image guidance has brought about revolution in the field of cytological diagnosis. Because of high degree of accuracy and minimum discomfort to the patient through this technique permits the accurate localisation of non-palpable and deep-seated lesion in the body. Image guided FNAC is routinely done in when single and multiple lesions are located in inaccessible site. It is very important to confirm the diagnosis as well essential for both initiation of treatment and categorisation of cancer according to stage [3].
USG proposes numerous benefits as a guidance system for biopsy. It is quite affordable, easily available and mobile; it can provide imaging in many tissue planes like transverse, longitudinal and oblique. It is free of harmful ionizing radiation. The utmost benefit of this system is that needle tip can be seen while performing USG (real time) and this tip can be seen passing through various tissue levels of the target area [4]. In case of malignant lesions FNAC has shown 100% specificity and is considered to be the first choice for evaluation of abdominal lesions [5,6,7]. These advantages emphasize the need to establish USG guided FNAC of intraabdominal masses as a diagnostic modality and facilitates treatment planning. Histopathological correlation aids in sensitivity and specificity of Ultra sound guided FNAC thereby making it first investigation of choice for evaluation of intraabdominal masses.

Research Gap
The aim of present study to assess the utility of "Ultra sound guided fine needle aspiration cytology of intra-abdominal masses and their histopathological correlation."

Research Question
With the understanding of results obtained from "USG guided fine needle aspiration cytology of intra-abdominal masses and their associated histopathological evaluation", the following research question is framed-"Does correlation exists between histopathology and ultrasound guided fine needle aspiration cytology of intraabdominal masses."

Study Design
Observational, analytical and prospective.

Methods
Prior informed consent will be taken from the patients participating in the study. Total 30 cases with clinical or radiological diagnosis of intraabdominal mass will be studied . Thorough clinical data in terms of patient's history, physical examination findings will be taken and related investigations will be done. The patients will undergo radiological examination (ultrasonography) to determine the source of the mass and its association with the nearby organs.
Fine needle aspiration of the abdominal lump will be done in the Department of Radiology, using real time USG in aseptic environment, using shortest route to target area, as to be recommended by the radiologist. The coagulation profile of all patients with abdominal mass will be done. A commercial disposable 22gauge needle fitted to a 10ml plastic syringe will be utilized. For deeply situated lesions, 9cm long 22 -gauge spinal needle will be utilized. Several smears will be made and promptly will be fixed with 95% alcohol fixative. These smears will be stained by using 'Papanicolaou's stain and Haematoxylin and Eosin stain (H & E).' Smears will be air dried and stained with Giemsa stain. Whenever required special stains such as 'Ziehl Neelsen' and 'Periodic Acid Schiff' can be utilized. Whenever fluid will be obtained, macroscopical evaluation of fluid and centrifugation will be done. Smears will be made from sediment and then stained by appropriate stains. Each smear will be examined after staining under 10X magnification to get idea of overall cellularity, then under 40X magnification to get morphological details of individual cells. The smear will be categorized into inflammatory, benign, malignant lesions on the basis of individual cell and nuclear morphology. Resected intra-abdominal masses will undergo histopathological evaluation and correlation will be made with outcome of USG directed fine needle aspiration cytology. The collected data will be tabulated and results will be calculated and analysed by using appropriate statistical methods.  Patients in which peritonitis is suspected 3.
Swellings arising from uterus, cervix, prostate, bone and abdominal wall.

Statistical Analysis
Proportions, Chi square/t-test for proportions, bars, charts, contingency tables, frequencies and percentages will be used for statistical evaluation.

EXPECTED RESULTS
The study will be conducted for a period of 2 years and all the observations will be depicted in a well-tabulated master chart.  2%). The sensitivity of their study was 89.7%. They concluded that "ultrasound guided FNAC is a sensitive investigative method in a wide range of intra-abdominal neoplastic and non-neoplastic lesions." [1].

Mishra BM et al evaluated intra-abdominal lumps
where special reference was given to ultrasonography and FNAC. Eighty cases were included in the study. Male predominance was observed and malignancies were more common than benign lesions. Amongst the malignancies, carcinoma of stomach (45%) was the most common. False positive and negative diagnosis in the study was noted to be 2.5% and 15% respectively. The diagnostic accuracy was recorded to be 82.5% [12].
Pereiras RV et al used Chiba needle. Their technique permitted that without doing high risk exploratory surgery cytological diagnosis of malignancy can be done. Which also suggested that this technique can prevent prolonged hospitalization of patient and also early initiation of treatment is quite possible [13].
Ahmed SS et al did a study on 200 patients with abdominal lump. These patients were subjected to USG guided FNAC and cytohistological correlation was done. Overall sensitivity and specificity were 94.11%, 100%, respectively, with 95.7% of diagnostic accuracy [14].
Abdominal masses are known to propose clinical dilemma to the surgeon. So, differentiation between neoplastic and non-neoplastic lesions are crucial, especially in case of advanced non resectable neoplastic lesions to prevent exploratory laparotomy. FNA is considered to be more precise and sensitive than core needle biopsy [15].
Ultrasonography (USG), a new diagnostic imaging technique, that has enhanced the outcome of surgical biopsies in terms of localization of lesions which are difficult to access as well diagnostic accuracy. For deeply situated lesions image guided FNA found to be a good modality with high sensitivity. It has reduced time taken to diagnose a lesion as it can be performed as the first step in the patient's diagnostic workup, thereby it can be considered as satisfactory rapid diagnostic tool for the clinician [4].
In this modern era of technology different types of tissue imaging techniques like fluoroscopy, computerized tomography (CT), ultrasound (USG) are available which we can use as a guide for FNA of abdominal masses. But, out of all these, ultrasonography has an upper hand over others because of its rapidity, reproducibility and versatility. It is safer as no ionizing radiation are used [9]. As we know Maximum of the intra abdominal masses are clinically non-palpable and even if they are palpable, it is very difficult to know the extent, shape and size of lesion [14]. Before initiation of therapy, a documented evidence of the type of the pathology is obligatory. It is also important for prognostication of disease. In most of the cases, results achieved by FNAC can be utilized as substitute for surgical procedures like diagnostic laparotomy [16].
FNA is an ideal outpatient procedure which can be used for the diagnosis of lesions of any location. Accuracy and benefits of FNAC are backed by many literatures but they also stated need for caution in interpretation. This technique also requires meticulous attention as it has its own limitations in terms of diagnosis [17].
The benefits which makes USG superior than CT scan for FNA are that it is quick, cheap, and versatile, also without any risk of radiation exposure, can be easily repeated when necessary & no contrast medium is required [18].

CONCLUSION
Conclusion will be drawn from the outcome of the study.

CONSENT
Prior informed consent will be taken from the patients participating in the study.

ETHICAL APPROVAL
It is not applicable.