Cryptorchidism, the condition characterized by the absence of one or both testes from the scrotum, is the most prevalent birth defect of the male genitalia. It affects approximately 3% of full-term male neonates and up to 30% of preterm neonates. However, its occurrence decreases to 1% between the ages of 6 months and 1 year [1].

Several factors have been identified as predisposing to cryptorchidism, including prematurity, low birth weight, low gestational age, twinning, and maternal exposure to cigarette smoking and alcohol during pregnancy [1]. If left uncorrected between the ages of 6 months and 1 year, spontaneous descent of the testes is less likely to occur [3].

Cryptorchidism poses risks such as testicular cancer, ischemia, and infertility later in adulthood. Testicular seminoma is the most commonly observed malignant transformation of the undescended testis [4].

Testicular seminoma is a type of germinal cell tumor originating in the germinal epithelium of the seminiferous tubules within the testicle [2]. It accounts for approximately half of all testicular germ cell tumors and stands as the most prevalent malignancy among males aged 15 to 35 years [5]. Individuals with a prior history of cryptorchidism face a significantly heightened risk, being 10 to 40 times more prone to developing testicular seminomas [1].

The documented susceptibility of the undescended testis to malignant transformation, typically into seminoma, is widely acknowledged. This risk is notably reduced to 2 to 3 times the risk of the orthotopic testis if prepubertal orchidopexy is performed. Rates of malignancy in intra-abdominal testes have been reported as 5 times higher than the average malignancy rate in all undescended testes [6].

The undescended testis can be found at various points along the pathway of testicular descent, but the majority, around 66%, are situated distally to the external inguinal ring. Approximately 16% are located within the inguinal canal, while 10% remain in the abdominal region [7]. Additionally, it's noteworthy that an abdominal testis is four times more prone to developing tumors compared to an inguinal testis [8].

The exact pathophysiology driving the heightened risk remains unclear. Hypotheses suggest potential mechanisms such as abnormal temperature elevation leading to cell mutation, or the disruption of a shared regulatory pathway contributing to both maldescent and testicular cancer [9].

In cases of an undescended testicular seminoma, located in the abdominal area, clinical presentation can vary significantly. This range includes an asymptomatic mass to symptoms that mimic appendicitis, as well as symptoms related to mass effect or acute abdominal pain resulting from torsion or hemorrhage [7]. On the other hand, when it is located in the inguinal region, the most classic symptom is the appearance of a mass that mimics an inguinal hernia, but which is not reductible and can sometimes be painful, this highlights the importance of a scrotal examination in these situations [10].

Ultrasound exhibits a sensitivity as high as 95-97% in locating an inguinal testis. It could play a role in planning elective surgery to locate a non-palpable testis, as it may also detect a "peeping" testis, which is a testis that can variably be felt at the deep inguinal ring and can migrate back and forth through it. MRI may prove useful in identifying an intra-abdominal testis [10]. Seminoma typically manifests as a nodular appearance with homogeneous low signal intensity on T2-weighted MRI images [11].

The definitive diagnosis is ultimately established through histopathology. Histopathological examination typically reveals sheets of relatively uniform tumor cells with abundant clear or watery cytoplasm, characterized by large central nuclei with prominent nucleoli. These cells are often divided into poorly demarcated lobules by delicate fibrous septa and show minimal mitotic figures [2,5] The histopathological findings observed in our sample align with those commonly reported in the literature. If there is any doubt about the diagnosis, immunohistochemistry may be used. The tumour cells are positive for a panel of markers such as : SALL4, SDHB, CD117, D2-40, Ki-67 and PLAP [12].

Testicular seminoma can present and manifest itself through complications. The potential complications most frequently described in the literature are torsion of the cord of the tumor testicle and rupture of the testicle with hemorrhagic shock. (10) Abdominal cocoon syndrome has even been described, with a seminoma testis located intraabdominally [12].

Testicular cancer boasts a high survival rate of 97% at 5 years when detected and treated early [13]. However, delayed diagnosis can occur for various reasons, including patients not seeking medical advice regarding an otherwise asymptomatic empty scrotum or the challenge in diagnosing non-specific symptoms like abdominal ache or bloating [13,14]. Upon diagnosis, it's notable that 15% of pure seminomas have already metastasized and may present with symptoms such as abdominal pain or masses [14].

Initially, surgical management for adults with an uncomplicated intra-abdominal or inguinal testis typically involve orchidectomy, although there's been a shift towards conservative management with imaging surveillance. For patients with orthotopic testicular seminomas, approximately 80% of whom present with stage I disease, radical inguinal orchidectomy remains the preferred initial treatment. In the absence of adjuvant therapy, modern surveillance programs have shown a relapse rate of approximately 12–15% within the first three to four years, with an overall relapse rate of approximately 18%–20% over ten years [15].

Seminoma exhibits high sensitivity to radiotherapy and chemotherapy, and patients with stage I disease typically have favorable outcomes, achieving a 5-year cause-specific survival of 99.9% when treated with adjuvant chemotherapy and 100% when treated with adjuvant radiotherapy. More advanced disease may necessitate combination chemotherapy and radiotherapy, while lymph node dissection plays a more limited role due to a low rate of viable tumor in small residual masses and increased desmoplastic reaction and fibrosis following surgery [3,6,15].

In the presented case, no lymphadenopathy or other evidence of metastatic disease was observed. Consequently, the patient was referred for treatment with adjuvant chemotherapy.

Peer-reviewed guidelines advocate for orchidectomy in post-pubertal males with cryptorchidism as a means to minimize the risk of cancer [16,17]. Surveillance is only recommended for older patients who carry a significant anesthetic risk [16]. Beyond the malignancy risk, undescended testes do not seem to heighten the risk of fertility issues or testicular torsion [6].