Abdominal wall endometriosis : experience of the General Surgery

Objective: to study the characteristics of women undergoing abdominal surgery with suspected abdominal wall endometriosis or abdominal wall tumor, and to assess the association with age, race and previous cesarean delivery. Method: retrospective and analytical study carried out from January 2000 to December 2019, at the General Surgery Service of Hospital Universitário Antônio Pedro (HUAP) at Universidade Federal Fluminense (UFF). Medical records of 100 patients with abdominal wall endometriosis and other types of abdominal wall tumors were analyzed. Age, color, previous history of cesarean section or abdominal surgery and histopathological data were verified. The patients were classified as young adults (aged between 18 and 28 years and 11 months) and adults. The SPSS program was used for data analysis, Fisher’s test with a significance level of 0.05. Results: abdominal wall endometriosis with histopathological confirmation was found in 22%, the mean age was 52.28 ± 18.66 which was lower when compared to other diagnoses. There was an association between previous cesarean section and abdominal wall endometriosis (p <0.005). Conclusion: the women with a diagnosis of abdominal wall endometriosis had undergone previous cesareans (the majority) and were in an active reproductive age. Although the brown skin women were the most frequent, there was no statistical difference.

favorable for the development of endometriosis than the endometrium of late pregnancy 10 .
When in the abdominal wall, endometriosis is preferably located close to a surgical scar. Although in most cases it occurs in patients with previous cesarean section 11,12 , it has also been observed in postoperative, conventional or laparoscopic, hysterectomy 13,14 , appendectomy and inguinal hernia incisions, and it has been described in patients without any previous intervention 15 . The classic symptomatology of abdominal wall endometriosis consists of a tumor that is very sensitive to palpation, intermittently painful, which increases in volume and sensitivity according to the phase of the menstrual cycle.
Regarding pathogenesis, no theory can fully explain the exact mechanism of formation of abdominal wall endometriosis, and it is likely to result from a combination of events. However, two theories suggest that the occurrence of abdominal wall endometriosis 16 , the most accepted being the hypothesis of contamination of the abdominal wall, particularly during uterine-opening procedures 8,17 . The other would be the occurrence of reflux, through the fallopian tubes, of particles from the endometrium to the abdominal cavity and blood and lymphatic vessels 8,17 . Another possibility would be the presence of primitive multipotential cells outside the uterus that under certain conditions would produce endometriosis, which would explain the presence of abdominal wall endometriosis in individuals who have not undergone previous surgery 5, 17,18 .
As signs and symptoms, we can highlight the presence of a tumor in the abdominal wall that increases in volume and causes pain, especially in the menstrual period 8,19 . In fact, the diagnostic suspicion must occur when the signs and symptoms clearly coincide with the phases of the menstrual period 20  and adults (over 29 years) 6,7 .

RESULTS
We defined the sample size by convenience, therefore using no calculation for it. With the aid of the

DATA ANALYSIS
We submitted the collected data to statistical analysis using the IBM SPSS software, version 20.0.
We assessed normality of the age variable with the Kolmogorov-Smirnov test and expressed it as mean ± standard deviation when there was a normal distribution and as median and range otherwise. We Table 1. Characteristics of the patients included in the study.

Results
Age, mean ± standard deviation 52. 28   The main complaint in all cases was a tumor on the abdominal wall that increased in volume and became more painful with the beginning of the menstrual period.
The tumor was located in the iliac fossa in 18 patients (eight on the right and 10 on the left), and in the left flank in one. All were located near the cesarean section surgical scar. In three cases, it was located in the umbilical region. All had, at palpation, imprecise limits, smooth   In all cases, there was extensive excision of the tumor and adjacent affected tissues (Figure 1). In six cases,  However, analysis of endometriosis according to age showed no significant difference. In fact, women with endometriosis were younger, but we found the highest frequency in the age group considered adult, no in the young adult one (Table 3). Table 3 also shows the association between endometriosis and color. We observed no significant difference between them. Regarding previous cesarean section, we found an association with endometriosis, that is, the majority (95%) of women with endometriosis underwent previous cesarean section (Table 3).

DISCUSSION
Endometriosis is a well-known disease in gynecological literature, but it is still not well understood among general surgeons 8   (2019) 12 . This age represents the stage in which the woman is reproductively active, initially described by Chun, Nelson and Maull (1990) 24 and also found in more recent studies 12,35,38 . However, we found no association between abdominal wall endometriosis and the age group of young adults; in fact, there were more adult women (88%).