von hippel  lindau ( vhl ) disease is a rare inherited condition affecting 1 in 36 000 births and is associated with the development of various multi - system tumours , including haemangioblastomas , phaeochromocytomas , renal cell carcinomas , endolymphatic sac tumours and papillary cystadenomas of the epididymis ( in men ) and broad uterine ligament ( in women ) .
although the association between vhl and primary epididymal papillary cystadenomas is well known , there is extremely limited information about its malignant counterpart ( i.e. papillary cystadenocarcinomas ) with only a few cases reported in the literature [ 26 ] .
the few case reports available have not been associated with vhl disease . as a result , there is also limited information regarding their optimal long - term management .
we present the first reported case of a 43-year - old gentleman with vhl disease presenting with azoospermia and subsequently diagnosed with a primary epididymal papillary cystadenocarcinoma , infiltrating the spermatic cord and accompanied by a metastatic deposit in the right testis .
the patient was ultimately managed by a combination of radical orchidectomy and onco - microtese .
a 43-year - old gentleman with known vhl disease and a history of multiple renal carcinomas presented with primary infertility and non - obstructive azoospermia . on examination , he had an atrophic left testis ( secondary to a previous orchidopexy for cryptorchidism ) and a firm mass in the right epididymis .
he was referred for testicular sperm extraction . at the time of surgical sperm retrieval ,
a biopsy was taken from the epididymal mass , which was reported as a cystadenocarcinoma .
a further biopsy was taken of a mass incidentally noted in the upper pole of the right testis , which on histology was suggestive of a metastatic deposit of renal cell carcinoma .
an orchidectomy was advised , but declined by the patient as he was keen to start a family .
after successfully having a child via in vitro fertilisation  ( ivf ) treatment , he re - attended the urology department for definitive management of his epididymal and testicular tumours .
he was asymptomatic and clinical examination revealed a palpable mass in the head of the epididymis measuring  ~1.5 cm .
a separate small mass was also palpable in the upper pole of the right testis .
blood tests revealed normal testicular tumour markers ( -fetoprotein , -human chorionic gonadotrophin and lactate dehydrogenase ) .
follicle stimulating hormone and leutenizing hormone levels were 36 and 13 miu / ml respectively , with a testosterone level of 12.2 nmol / l .
preoperatively , the optimal management strategy of his testicular and paratesticular lesions was complicated given the rarity of the case coupled with the challenge of multiple issues including : 
 future fertility preservation.atrophic , previously undescended , contralateral testis.borderline testosterone levels.propensity to develop further tumours on a background of vhl disease .
initially , a partial orchidectomy was considered to preserve future fertility . however , after review at the multidisciplinary team ( mdt ) meeting , it was felt that a radical orchidectomy was the safest oncologocial management option and was agreed by the patient .
this was performed via an inguinal approach and an onco - microtese ( microsurgical testicular sperm extraction in azoospermic cancer patients performed once the testicle has been removed ) was carried out to allow for future family planning .
isolated areas of dilated tubules were retrieved under 20 magnification with viable sperm cryopreserved for future ivf .
subsequent histological review revealed a multinodular tumour in the head and body of the epididymis , which exhibited varying architectural patterns .
in some areas , the tumour resembled that of a classical papillary cystadenoma with papillary structures projecting into cystic spaces lined by cuboidal to columnar cells with pale eosinophilic to clear cytoplasm .
however , in other areas , the tumour was composed of cystic as well as solid sheets of polygonal cells with clear cytoplasm .
there was also a separate deposit in the upper pole of the testis , which was composed of cystic spaces filled with eosinophilic secretions and lined by polygonal cells with clear cytoplasm .
based on the immunohistochemical findings , it was felt that the intratesticular tumour deposit most likely represented a metastasis from the papillary cystadenocarcinoma of the epididymis ( figs 1 and 2 ) . 

the epididymal tumour resembled that of a classical papillary cystadenoma ( 4 magnification ) . 

figure 2:histology of separate tumour deposit in testis composed of cystic spaces filled with eosinophilic secretions and lined by polygonal cells with clear cytoplasm ( 4 magnification ) .
histology of epididymal tumour showing varying architectural patterns . in some areas , the epididymal tumour resembled that of a classical papillary cystadenoma ( 4 magnification ) .
histology of separate tumour deposit in testis composed of cystic spaces filled with eosinophilic secretions and lined by polygonal cells with clear cytoplasm ( 4 magnification ) .
given the unusual nature of the case , the unknown prognosis of papillary cystadenocarcinomas and the lack of established treatment protocols post - orchidectomy , an mdt decision of close clinical surveillance with regular follow - up was made .
papillary cystadenomas of the epididymis are known to occur in association with vhl disease . however , the development of a papillary cystadenocarcinoma , its malignant counterpart , is incredibly rare .
there is a single case report , which has documented metastases from such tumours to the paraureteral region .
however , metastasis to the testis has not been previously reported in the available published literature .
the presentation on a background of infertility and atrophic undescended contralateral testis raises further dilemmas in management .
surgical debulking remains as the cornerstone for the treatment of primary malignant epididymal tumours either via partial or radical orchidectomy .
a radical orchidectomy was considered to be the optimal treatment in view of the nature and location of his tumour , but the limited functional potential of his contralateral atrophic testis made his management more challenging . in this case ,
fertility preservation was paramount to the patient . combining his radical orchidectomy with a simultaneous surgical sperm retrieval using an onco - microtese allowed safe oncological management and optimal fertility preservation .
referral to specialist units with expertise in performing onco - microtese is important in such difficult cases .
written consent was obtained from the patient for publication of this case report and the accompanying images .
 papillary cystadenomas of the epididymis are known to occur in association with von hippel  lindau ( vhl ) disease . 
 the development of a papillary cystadenocarcinoma , its malignant counterpart , is rare with only a few sporadic cases reported in the literature . 
 metastatic deposits are exceedingly uncommon ; in fact , only a single case report has documented metastases to the paraureteral region , but metastases to the testis have never been reported . a 43-year - old gentleman with vhl disease presented with non - obstructive azoospermia , a right epididymal mass , and an atrophic surgically corrected undescended left testis . 
 the epididymal mass was reported as a papillary cystadenocarcinoma on biopsy . 
 the patient was managed with a radical inguinal orchidectomy and bench microtese with successful sperm retrieval . 
 metastatic papillary cystadenocarcinoma of the epididymis to the testis has never been previously reported . 
 this case was managed by radical orchidectomy and subsequent onco - microtese , allowing safe oncological treatment and optimal fertility preservation . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONSENT
CONFLICT OF INTEREST STATEMENT