A total of 501 CE surgical cases were diagnosed and underwent surgery in two main hospitals in the 15-year period from 2004 to 2018, giving an average annual incidence of 33.4 cases. The mean age of the patients was 34.92 (±19.87) years. The youngest patient was a 2 years old girl and the oldest one was a 96 years old man. The majority of the cases (26.4%) were ≥ 50 years old. Out of 501 CE cases, 242 (48.6%) were male while 256 (51.4%) were female. The highest frequency of cases (62: 12.5%) was recorded in the year 2017. Figure 1 shows the frequency of CE cases, per year.
Considering the residential areas of the patients, the majority of cases (76%) originating from Fars Province, whereas cases from neighboring Provinces mainly Kohgiluyeh and Boyer-Ahmad (7%) and Bushehr (4.4%), were also among the patients.
The most commonly involved organs were liver (339 cases; 57.8%), and lung (279 cases; (47.6%). Also, 46 (7.8%) cases had hydatid cyst in other locations including spleen, heart, diaphragm, etc. Concurrent involvement of two organs was seen in 58 (9.9%) cases of both lung and liver, 10 (1.7%) cases of lung and other locations (excluding liver) and 22 (3.8%) cases of liver and other locations (excluding lung). Table 1 shows the location of hydatid cyst in CE cases in southwest Iran.
Table 1 location of hydatid cysts in CE cases in southwestern Iran, based on hospital record, during a 15-year period (2004-2018)
Location
|
Frequency (No.)
|
Percent (%)
|
Lung
|
279
|
47.6
|
Liver
|
339
|
57.8
|
Spleen
|
14
|
2.4
|
Pelvic cavity
|
7
|
1.2
|
Heart
|
4
|
0.7
|
Sub diaphragm
|
5
|
0.9
|
Abdominal and peritoneal cavity
|
5
|
0.9
|
Other locations*, **
|
12
|
2
|
Lung and liver
|
58
|
9.9
|
Lung and Spleen
|
2
|
0.3
|
Lung and Pelvic cavity
|
1
|
0.2
|
Lung and sub diaphragm
|
2
|
0.3
|
Lung and Heart
|
2
|
0.3
|
Lung and other locations*
|
3
|
0.5
|
Liver and Spleen
|
6
|
1
|
Liver and pelvic cavity
|
6
|
1
|
Liver and sub diaphragm
|
3
|
0.5
|
Liver and abdominal and peritoneal cavity
|
3
|
0.5
|
Liver and other locations**
|
5
|
0.9
|
Spleen and pelvic cavity
|
1
|
0.2
|
* CBD, mediastina, pancreas
** Kidney, mediastinum, mesothelium of the terminal ileum, pancreas, psoas muscle
Multiple organ involvement of lung, liver, and spleen were seen in 2 (0.3%) cases, lung, liver and pelvic cavity in 1 (0.2%) case, lung liver and sub-diaphragm in 1 (0.2%) case, and lung liver and pancreas in 1 (0.2%) case.
Secondary hydatid cyst or relapse were seen in 67 (13.37%) of the patients, in which the secondary cysts in 28 (41.8%) were lung cysts, 42 (62.7%) were liver cyst, 1 (1.5%) was pelvic cyst, 1 (1.5%) was spleen cyst, 1 (1.5%) was abdominal and peritoneal cavity and 1 (1.5%) was in the mesothelium of the terminal ileum. It is worth mentioning that 11 of the cases underwent surgery due to tertiary hydatid cyst or relapse for the third time and also 3 of the cases underwent a fourth surgery due to hydatid cyst. Table 2 shows the demographic features of the CE patients along with the cyst features.
From the 279 cases of lung hydatid cyst, the majority (174: 74%) had a single cyst while 46 (19.6%) cases had two and 15 (6.4%) cases had three or more cysts. It is worth knowing that from the 279 cases of lung hydatid cyst, 157 (56.3%) cases were male while 120 (43.3%) were female. There was a significant correlation between lung hydatid cysts and the patients’ gender (P=0.000).The size of the lung hydatid cyst varied, ranging between 2 to 24cm (mean = 7.33, SD= 3.737) with the highest frequency (175: 96.2%) of the largest diameter of the cyst being in group 11 to 15cm. The lung cyst area ranging from 2 to 490 cm2 (mean 42.27, SD = 50.061) with the majority in under 26 cm2 group (83:48.3%).
In our study, among the 339 cases of liver hydatid cyst, 194 (68.1%) had single cysts, 56 (19.6%) had two cysts, and 35 (12.3%) had three or more cysts. The size of liver hydatid cysts ranged from 1 to 26 cm (mean: 9.04, SD= 4.275) with the highest frequency of the largest diameter of the cyst being in group 6 to 10 cm. The area square centimeters of the liver cyst ranged from 1 to 392 cm2 (mean= 58.43, SD= 52.556) with the majority (82: 31.9%) in under 26 cm2 group.
In other locations, apart from lung and liver, the number of cysts varied were 21 (3.6%) cases had only a single cyst, 7 (1.2%) cases had two cysts, 8 (1.4%) cases had three or more. The size of the cysts varied, ranging between 2 to 18cm (mean=8.73, SD= 4.527) with the highest frequency (19: 55.9%) being in the 6 to 10cm group. The area square centimeters of the cysts in other locations ranged between 3 to 314cm2 (mean= 59.14, SD= 64.287).