it is incidentally found in autopsy specimens and surgical specimens with cryptorchidism and testicular germ cell tumor .
this non - neoplastic lesion is usually seated in the mediastinum and septal part of the rete testis .
it may present as a very small lesion detected in microscopic examination or a solid - cystic mass lesion which is macroscopically evident . in microscopic evaluation
cryptorchidism was unilateral and the other testis was normal . there were no clinical or endocrine abnormalities .
the testis measured 4  2.5  2.2 cm in size and there was no tumoral lesion in gross examination . on the cut section close to the testis parenchyma , there was a gland like tubular structures .
some of these were in back - to - back position with little intervening stroma .
the testicular parenchyma was comprised of seminiferous tubules that had sertoli cells only and no spermatozoa ( fig .
ema ( novocastra ; 1/150 , clone gp 1.4 , newcastle , united kingdom ) and pankeratin ( novocastra ; 1/150 , clone ae1/ae3 , newcastle , united kingdom ) immunohistochemical stains were performed for diagnosis .
adenomatous hyperplasia of the rete testis is a benign lesion which can appear at any time during life and was first described by nistal et al . 
 .
it is important to recognize tumor - like lesions of the rete testis to make an accurate differential diagnosis whether the lesion is benign or malign .
ahrt etiology is not well understood yet but there seem to be associated conditions such as cryptorchidism , some kidney diseases , and germ cell tumors .
our case was cryptorchid and seminiferous tubules near the lesion were lined by only sertoli cells and had no spermatozoa .
the authors reported an adult case with ahrt in unilateral testis with no luminal spermatozoa .
there are different cases such as prostate adenocarcinoma or embryonal carcinoma together with ahrt in the literature [ 6 , 7 ] .
the true epithelial proliferation with gland - like or papillary proliferations replacing normal epithelium , continuous architecture of normal rete testis with adenomatous hyperplasia and lack of signs of malignancy are the proper diagnostic criteria for ahrt . in our case
the differential diagnosis should include adenoma , papillary adenoma , primary and metastatic adenocarcinoma and rete testis cystic transformations with epithelial metaplasia .
clinical history , localization , histologic features and immunohistochemistry are criteria for differentiating these lesions .
complete surgical resection is the proposed therapy for ahrt cases and no report for recurrence has been identified . in conclusion ,
adenomatous hyperplasia of the rete testis is a rare lesion that can be confused with malignancy and should be remembered in the differential diagnosis of rete testis lesions .
 there are several tumor - like lesions and miscellaneous neoplasms of the rete testis . 
 we present a case with adenomatous hyperplasia of the rete testis ( ahrt ) . 
 the patient was 24 years old with undescended testis and was referred to our hospital . 
 there were no clinical or endocrine abnormalities . 
 cryptorchidism was unilateral and the other testis was normal . 
 right orchiectomy was performed and sent to the pathology laboratory for examination . 
 morphologic and immunohistochemistry findings confirmed the diagnosis of ahrt in this case . 
 the patient 's postoperative course continues uneventfully . 
 ahrt is a rare lesion and can be confused with malignancy . 
 it is incidentally detected in microscopic investigation . 
 it may present as a very small lesion detected in microscopic examination or a solid - cystic mass lesion which is macroscopically evident . clinical history , 
 localization , histologic features and immunohistochemistry are criteria for differentiating these lesions.we present this rare case for both surgeons and pathologists due to its importance as it can be confused with malignancy . 
Introduction
Case presentation
Discussion
None