Introduction
Retroperitoneum is that portion of the abdomen located posterior to the peritoneal cavity. It is divided into three spaces by the anterior and posterior renal fascia. The anterior pararenal space is bordered anteriorly by the parietal peritoneum, posteriorly by the anterior renal fascia and posterolateral by the lateral continuation of the renal fasciae and the lateroconal fascia. This space contains the pancreas, retroperitoneal portion of the duodenum, and ascending and descending colons.
The perirenal space lies within the anterior and posterior renal fasciae and contains the kidneys, adrenals, proximal collecting systems and renal hilar vessels. The posterior pararenal space is the smallest of the three retroperitoneal spaces. It is located posterior to the posterior renal fascia and contains only a small amount of fat The psoas compartment, sometimes considered a fourth retroperitoneal space is located within and immediately adjacent to the psoas muscles.
Since its introduction in the 1970s, CT has become the primary imaging modality for imaging of the retroperitoneal structures because of its superior spatial resolution, its widespread availability and the speed in which examination can be performed. Much faster acquisition capability of current CT units strongly favour their use in patients who are critically ill or medically unstable. 1
Materials and Methods
The cross sectional study was carried out in the department of Radio Diagnosis, M.K.C.G Medical College, BERHAMPUR 50cases of retroperitoneal MASSES belonging to different age group referred from General Surgery, Urology, Gastroenterology, Medicine and Paediatrics IPD and OPD between the period from October2018 to OCTOBER 2020 have been included in the study.
Detailed clinical history was recorded in each case as per the proforma attached in appendix. Routine investigations like hemogram, blood urea/creatinine, blood sugar, chest X-ray done in these patients have also been recorded.
Ultrasound and CT scan (both NECT, CECT) were done in all suspected cases. The radiological features were correlated with surgical and postoperative histopathological findings. Diagnosis of lesion with respect to its anatomical location and characterization and find out incidence of different retroperitoneal masses in southern belt of Orissa.
Ultrasound was used to complement and supplement CT in the diagnosis of retroperitoneal tumours. Ultrasound was done using SHIMADZU 450 XL located in the Department of Radio diagnosis, M.K.C.G Medical College, Berhampur. Probe frequency varied from 2.5 to 5 MHz CT scan was done by SIEMENS SOMATOM ESPRIT located in the Department of Radiodiagnosis M.K.C.G Medical College, Berhampur. KODAK LASER/ DRY VIEW CAMERA and KODAK 14"x l7"films were used for prints. Non contrast and contrast enhanced axial scans were done in all the cases.
The patients were kept supine in the CT table with head properly positioned in the head rest. CT was performed in transverse axis 5 mm thick slices were taken from top of diaphragm to pubic symphysis level. If required further thin slices were taken for better characterization of lesion and to eliminate partial volume averaging. Non contrast CT is especially helpful for detection of intralesional haemorrhage and calcification.
After non contrast CT, 75 ml of 76% non-ionic contrast was administered intravenously as bolus. Scanning was then repeated and enhancement pattern of the lesion studied. Coronal and sagittal reconstruction were done wherever required to better appreciate the three dimensional anatomy of the lesions. The results obtained from clinical examination, ultrasound and CT scan were correlated with postoperative surgical and histopathological findings. Available literature was reviewed and compared with present findings.
Results
This section deals with the observation part of the study. Variables of both clinical and imaging parameters have been compiled, collated and analysed below.
Table 1
Age and sex distribution
|
Age in Years |
Male |
Female |
Total |
|
0-10 |
5 |
2 |
7 |
|
11-30 |
0 |
2 |
2 |
|
31-50 |
4 |
2 |
6 |
|
51-70 |
22 |
11 |
33 |
|
71-90 |
2 |
0 |
2 |
|
Total |
33 |
17 |
50 |
From the table above, it can be found that majority of cases (66%) are found in the ages group of 51-70 years. Further, it can be noted that males outnumber females in a ratio of 1.94:1.
Table 2
Clinical presentation in descending order of frequency
|
|
Number of Cases |
Percentage |
|
Mass abdomen |
20 |
40 |
|
Pain |
10 |
20 |
|
Jaundice Haematuria |
8 |
16 |
|
Jaundice |
7 |
14 |
|
Weight Loss |
5 |
10 |
Figures from the above table point to the fact that mass in the abdomen is the most common presenting feature seen in 40% of cases.
Table 3
Site and compartment of origin
It can be observed that renal masses are the most common retroperitoneal mass (48%) followed by pancreatic mass (32%). It can averaged from the above table that retroperitoneal masses are most commonly found in the perinephric space (60%).
Table 4
Types of masses in studied
The above tables shows that renal cell carcinoma is the most common renal mass (66.6%). pancreatic adenocarcinoma is the most common pancreatic mass 68.7%. It is clear from the above table that neuroblastoma was the most common suprarenal mass (40%).
It can be inferred that all the above mentioned masses have equal incidence (20%).
Table 5
CT findings in retroperitoneal masses
CT in diagnosing retroperitoneal masses has 96% accuracy of evaluating the cause of retroperitoneal masses. In the series, histopathological correlation was done in all the cases. Diagnostic discrepancy was noted in one case of adrenal metastasis which was later confirmed as adrenal adenoma
Figure 1
NCCT, CECT of Abdomen Shows Left Suprarenal mass showing Homogenous enhancement, Thin Rim Like capsule with posterior Displacement of Left Kidney Diagnosis: Left adrenal carcinoma.
Discussion
In this study conducted over a period of 2 years (Oct 2018 to Oct 2020) in the Department of Radiology, M.K.C.G Medical College & Hospital Berhampur, the clinical and CT features of retroperitoneal masses in 50 patients have been analysed. Age and sex distribution of 50 cases included in the study. There were 33 male patients and 17 female patients with a male to female ratio of1.94:1. Male to female ratio in renal mass was 3 :2, which correlates well with the studies of Coulange et al. 2 who studied 970 patients of renal cell carcinoma and found the male to female ratio to be 2 :1 and Yonedo et al 3 who studied 132 patients and found the male to female ration to be 2.07:1.
Maximum number of cases were seen in the age group 51 -70 years. Majority of renal cell carcinoma patients were in the age group 51 - 70yrs (66%) which correlates well with the study of Delahunt et al.4 who studied 1308 patients and found the majority of patients to be in 51 - 70 years age group (72%).
The most common clinical presentation in retroperitoneal masses was mass abdomen (Table 1). In renal cell carcinoma, the most common clinical feature was haematuria (60%). This is in accordance with the study of Yonedo et al. 3 who studied 132 patients of renal cell carcinoma and found the most common clinical symptom to be haematuria (55.4%). The classic triad of gross haematuria, flank pain and palpable flank mass was found in 10% of patients. This correlates well with the study of Yonedo et al.3 in which the classic triad of gross haematuria, flank pain and palpable flank mass was found in 12% of patients.
Jaundice was seen in 80% of cases of pancreatic adenocarcinoma arising in the head/periampullary region. This was in accordance with the study of Balthazar et al. 5 in which jaundice was a presenting feature in 83% of patients with pancreatic adenocarcinoma.
Renal cell carcinoma was the most common retroperitoneal tumour followed by pancreatic adenocarcinoma (Table 2). Renal cell carcinoma was the most common renal mass (Table 3). Pancreatic adenocarcinoma was the most common pancreatic mass constituted 68.7% of pancreatic tumours which correlates with the study of Lin Y et.al in which pancreatic adenocarcinoma constituted 70% of pancreatic tumours.6
VII shows the CT features of retroperitoneal tumours. Calcification was found in 20% of cases of renal cell carcinoma. This correlates with the study of Zagoria et al. 7 in which calcification was found in 25% of cases of renal cell carcinoma.
In all cases of pancreatic adenocarcinoma, mild contrast enhancement was seen. This was in accordance with the study of Balthazar et al5 in which all cases of pancreatic adenocarcinoma showed mild contrast enhancement 62% of cases of pancreatic adenocarcinoma were located in the head and 37.5% were located in the body and tail, this correlates with the study of Becker AE et al.8 in which 60% of cases of pancreatic ductal adenocarcinoma were located in the head and 35% were located in the body and tail. Abrupt termination of pancreatic duct and/or common bile duct was present in all cases of pancreatic adenocarcinoma. This correlates with the study of Baron et al,9 in which all cases of pancreatic adenocarcinoma had abrupt termination of pancreatic duct and/or common bile duct.
Conclusion
It is concluded from the above study that CT is an essential diagnostic modality in diagnosing and characterizing retroperitoneal masses. It establishes the location of such masses (anterior pararenal space, perinephric space, posterior pararenal space) and shows in great detail the associated findings such as cystic mass lesion tumoral calcification, haemorrhage, invasion of contiguous structures, vascular encasement and distant metastasis. It helps clinician to plan the treatment properly before any surgery is contemplated.
