A rare content of congenital inguinal hernia: a case report of splenogonadal fusion
Splenogonadal fusion (SGF) is a rare congenital malformation that occurs during embryonic development. SGF typically presents as a left-sided scrotal swelling, left inguinal hernia, scrotal mass, or cryptorchidism. Therefore, it is easily misdiagnosed, and unnecessary orchiectomy may occur. This study aimed to report a rare case of SGF.
A 5-month-old male child presented with a history of obvious left scrotal swelling for 1 month, which progressively worsened 10 h before the hospital visit. The ultrasound examination exhibited a solid mass in the left scrotum, with echo quite similar to that in the testicle and went up into the abdominal cavity through an identical echogenic band structure. After surgical resection, the pathological examination confirmed that the submitted tissue was spleen tissue with extensive bleeding.
Ultrasound can provide important information regarding the diagnosis of SGF. The possibility of SGF should be considered for further differential diagnosis in the case of similar patients.
KeywordsCongenital malformation Inguinal hernia Pathology Splenogonadal fusion Ultrasound
Splenogonadal fusion (SGF) is a rare congenital malformation in which the spleen is abnormally connected to the gonads or rarely to the mesonephric structures such as vas or epididymis . SGF typically presents as a left-sided scrotal swelling, left inguinal hernia, scrotal mass, or cryptorchidism . To date, only a few cases of SGF have been reported worldwide. However, ultrasound manifestations of SGF are seldom reported. As a nonradiative and economical inspection method, ultrasound is often used as the first choice for superficial mass inspection, including scrotal lesions. SGF is usually misdiagnosed in most cases as testicular tumors, necrotic intestines, multiple testis, and so on. A priori knowledge of this condition can avoid unnecessary orchiectomy.
A 5-month-old male child with a history of obvious left scrotal swelling for 1 month was admitted to the emergency department of West China Hospital of Sichuan University (Chengdu, China). In the beginning, swelling and regression of the left scrotum alternated. The parents did not pay enough attention. However, 10 h before the visit, the swelling of the left scrotum progressively worsened and the color of the left scrotum wall turned red. No other abnormalities were found in the physical examination except for a soft and nonreturnable mass in the left scrotum. Specifically, the transillumination of the scrotum was negative.
Discussion and conclusion
Inguinal hernia repair is one of the most common surgical procedures performed in children worldwide [3, 4]. Inguinal hernia is a relatively common surgical problem in children, with a reported incidence ranging from 0.5 to 4.5% [5, 6]. The cumulative incidence of inguinal hernia repair is 7% in male patients and 1% in female patients for children aged less than 15 years . Splenogonadal fusion is a rather specific type of inguinal hernia in a male patient, characterized by its ectopic spleen tissue. As a rare congenital malformation, SGF is associated with other malformations such as cleft palate, micrognathia, cardiac anomalies, spinal anomalies, and so on .
Classically, splenogonadal fusion is classified into a continuous type that depicts a connection between the spleen and the gonad, and a discontinuous type that may demonstrate an ectopic focus of splenic tissue attached to the gonad . These two types occur at relatively equal frequencies . In the continuous type, the connection band may provide strong evidence for the diagnosis of SGF. The connection between the mass in the scrotum and the spleen can be determined by the connection band. However, the discontinuous type may have a higher rate of misdiagnosis compared with the continuous one. For example, it can be misdiagnosed as testicular or epididymal tumors, thus leading to inappropriate surgical decisions. The patient in this study belonged to the continuous type. Regrettably, this study failed to show the complete connection band between the mass and the spleen because of the obstruction of gas in the intestine. Finally, the lesion was completely removed during the surgery. No abnormalities occurred during the follow-up. The parents of the child were satisfied with the entire diagnosis and treatment process.
Generally considered, the adherence of the splenic primordium to structures derived from the mesonephric ridge occurs between the fifth and eighth weeks of gestation. The descent of the testis seems to draw out the developing spleen into a long band in some cases or to detach a portion of the splenic primordium and carry it down with the descending testis in others . Abnormal development at this stage can lead to SGF.
Magnetic resonance imaging is valuable for the diagnosis of SGF . However, it is less suitable for infants and young children who are not easily controlled unless sedatives are used. SGF is mostly found in infants and young children. In the early years, 99Tc-sulfur colloid imaging was used to identify ectopic splenic tissue . However, the role of ultrasound in the diagnosis of SGF has rarely been reported. This study depicted the performance of ultrasound in the diagnosis of SGF. The gray-scale ultrasound revealed a mass in the left scrotum with echo similar to that in the testicle, and the echogenic band structure went up into the abdominal cavity; however, this might not be the case in different types of SGF. The ultrasound has its own limitations and is susceptible to abdominal gas. Under conditions of fasting, the ultrasound may exhibit that the band is connected to the spleen in the continuous type by switching probes of different spectra. The blood supply is decided based on the necrosis in the inside of the mass.
In an early study, 37% of the reported cases were associated with orchiectomy , and unnecessary orchiectomy led to a high rate of misdiagnosis. Clinical awareness of SGF may avoid more invasive surgery and even unnecessary orchiectomy.
SGF is a rare congenital malformation that typically presents as a left-sided scrotal swelling, inguinal hernia, scrotal mass, or cryptorchidism. Ultrasound can provide important information regarding the diagnosis of SGF with seldom contraindications, no radiation, and no need for sedatives. Hence, it is more practical for infants and young children. The possibility of SGF should be considered for further differential diagnosis in the case of similar patients.
We all cared for the patient and contributed to the writing of the report. XX:acquired the data and figures and drafted the original manuscript. YJ: was responsible for tracking and analyzing of the pathological result. J-x L: performed ultrasound scanning and diagnosis, and data collection. LQ: devised the original idea for the report and drafted and approved the final manuscript as submitted. All authors have read and approved the manuscript, and ensure that this is the case.
Design of the study and collection, analysis, and interpretation of data and in writing the manuscript were funded by the Natural Science Foundation of China (project code 81671696) and Sichuan Science and Technology Department Project (project code 2019YFS0219).
Ethics approval and consent to participate
Consent for publication
Written informed consent was obtained from the patient’s parent for publication of this case report and any accompanying images.
The authors declare that they have no competing interests.
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