seminoma is the most frequent carcinoma of the testicle in the fourth decade of life and constitutes 60% to 65% of germ cell neoplasias .
several histopathological characteristics of the tumour have been evaluated and three types of pure seminoma have been described : classic , anaplastic and spermatocytic .
we report a patient with seminoma arising in an undescended testis which presented as a palpable painful mass of lower abdomen .
a 29 year old man with no known previous complaint presented with 4 month history of progressively enlarging mass on his left lower abdomen .
the mass was slightly tender and located immediately above the left groin ( figure 1 ) .
ct scan revealed a mass of 211311 cm located between the abdominal subcutaneous and external oblique fascial layers .
mass was located immediately above the left groin he underwent surgery and en - bloc resection of the tumour via a left oblique flank incision was performed ( figure 2 ) .
the specimen demonstrated typical characteristics of classical seminoma with a smoothly demarcated fibrous capsule , which had a vascularized outer surface , and some spermatic chord structures were also identified macroscopically .
immunohistochemistry studies revealed plap ( plasental alchaline phosphatase ) positive ( figure 3 ) , p53 positive and cd45 negative tumour cells .
tunica vaginalis was intact , however , the tunica vasculosa that was located under tunica albuginea nested tumour cell piles ( positive lymphovascular invasion ) .
plap positive tumour cells ( x200 ) he was referred to oncology clinic after discharge .
germ cell tumours ( gct ) of testes can be benign ( teratomas ) or malignant ( seminoma and non - seminoma ) .
gct most frequently occur in the gonads , only 2 - 5% of them arise in extragonadal regions such as the mediastinum , retroperitoneum , pineal gland and sacral area ( 1 ) .
the undescended testicles carry 20 - 48 times higher potential for malignant transformation than the normally descended testicles ( 2 ) .
testicular ectopia is uncommon and the most frequent ectopic location of testis are superficial inguinal pouch , infront and lateral to the external inguinal ring and very rarely in the abdomen ( 3 ) .
the position of the undescended testis is related to the likelihood of carcinogenesis with intra - abdominal testis having the highest malignant potential .
the majority of undescended testes locate distal to the external inguinal ring and are palpable ( 2 ) .
exogenous estrogen administration to the mother during pregnancyhas been associated with an increased relative risk for testicular tumours in the fetus , ranging from 2.8 to 5.3 over the expected incidence .
other acquired factors such as trauma and infection - related testicular atrophy have been associated with testicular tumours ; however , a causal relationship has not been established .
our patient had his right testis in the scrotum and there was no palpable testis in the left scrotum .
this rapidly enlarging tumour was detected in the region betwen the external oblique fascia and the abdominal subcutaneous layer , distal to the external inguinal ring ( figure 4 ) .
exogenous estrogen administration to his mother during pregnancywas not reported . rapidly enlarging tumour distal to the external inguinal ring .
approximately 7 - 10% of testicular tumours develop in patients who have a history of cryptorchidism ; seminoma is the most common form of tumour these patients have .
however , 5 - 10% of testicular tumours occur in the contralateral , normally descended testis .
the relative risk of malignancy is highest for the intra - abdominal testis ( 5% ) and is significantly lower for the inguinal testis ( 1.25% ) ( 4 ) .
orchiopexy does not alter the malignant potential of the cryptorchid testis ; however , it facilitates examination and tumour detection ( 5 ) .
three clinical stages for the determination of the extension of the tumour have been described .
stage i is where the tumour is limited to the testis with or without invasion of epididymis or the spermatic cord . in stage
the germ cell tumour often gives lymph node metastasis , except from choriocarcinoma , which is characterized by early hematogenous spread .
age , tumour size , lymphovascular invasion , mitotic count , necrosis , percent of giant cell and tumour infiltrating lymphocytes are possible prognostic factors in the treatment of seminomas . in this particular case ,
the tumour was classified as stage i classical seminoma with positive lymphovascular invasion ( tunica vasculosa nested tumour cells ) .
unilateral rapidly enlarging tender abdominal wall mass with undescended testis should alert clinicians towards consideration of the possibility of seminoma and initiation of prompt intervention .
 seminomas in undescended testes may present as abdominal wall tumours . 
 a unilateral testis tumour in a 29 year old man with ipsilateral undescended testis is presented and relevant literature is reviewed.a 29 year old man presenting with a tender left lower abdominal mass was admitted to our clinic and initial diagnostic tests followed by abdominal computerized tomography ( ct ) and positron emission tomography / computerized tomography ( pet / ct ) were performed . 
 abdominal ct clearly demonstrated the tumour location between the lower left abdominal subcutaneous layer and the external oblique fascia . 
 he underwent surgery and the tumour was resected via en - bloc excision.pathological diagnosis of the resected specimen was consistent with classical seminoma and no distant metastasis was detected with pet / ct . 
 he was referred to oncology clinic after discharge.tumours of undescended testis can present as an abdominal wall mass and clinicians must be aware of their existence . 
INTRODUCTION
CASE REPORT
DISCUSSION