metastasis to the spleen is infrequent but varies greatly from series to series ( 1.6 to 30% ) , depending on the thoroughness of examination and selection of cases .
the most common primaries are lung cancer , cutaneous malignant melanoma , and breast cancer .
splenic metastasis generally indicates late dissemination of disease , and it is unusual to find isolated splenic lesions from solid organ malignancies , with fewer than 25 cases reported worldwide .
we report the case of a woman who presented with a splenic lesion 11 months after radical nephrectomy .
a 70-year - old caucasian female presented with a 4-week history of malaise and fatigue .
this renal tumour had been incidentally discovered on a follow - up abdominal ct scan she was having following a total abdominal hysterectomy and adjuvant radiotherapy for stage 1c endometrial carcinoma 4 years prior .
histological examination of the renal mass had shown a tumour of conventional clear cell type .
there was some invasion of the tumour into the perinephric fat and a segmental branch of left renal vein ( stage pt3b ) .
small deposits of tumours were noted on the surface of the fat resection margin . in light of this and the associated increased risk of recurrence
, she received a follow - up un - enhanced ct 6 months post - operatively which showed no recurrence , and was due further urological follow - up prior to her new presentation to the general practitioner 11 months post - nephrectomy with lethargy . at this time
she was found to be anaemic ( haemoglobin 10.4 g / dl ) and had a raised alkaline phosphatase level of 188 iu / l ( the remainder of liver function tests were normal ) .
a ct scan revealed an enhancing 6  7 cm necrotic lesion in the lower pole of the spleen , thought to be a metastasis from her previous rcc , with her previous endometrial carcinoma being a less likely primary .
it was uncertain whether this was indeed a true metastasis or a local recurrence of her previous left renal tumour .
there was no evidence of any other metastatic disease on cross - sectional imaging of the chest and abdomen .
after discussion in a multidisciplinary setting , although an uncommon event , the splenic lesion was thought likely to be an isolated splenic metastasis from her previous rcc and resection was recommended .
she elected to undergo surgery ( open splenectomy ) , had an uncomplicated procedure / recovery and was discharged from hospital on the eighth post - operative day .
serial slicing revealed a circumscribed centrally necrotic cream - coloured tumour measuring 90  63  55 mm ( fig .
, two fragments of diaphragmatic tissue were sampled to assess for any evidence of tumour spread .
histological examination of the splenic lesion showed a well - circumscribed , partly encapsulated tumour of solid islands and sheets of cells with an abundant amount of predominantly clear but also eosinophilic cytoplasm ( fig .
the tumour was found to bulge into the splenic capsule but no definite evidence of capsular breach was found .
there was also no evidence of vascular invasion and the lesion was clear of the splenic hilum .
no evidence of disease was found in histological samples taken from the diaphragm and therefore the mass was concluded to be a true metastasis of the original rcc rather than local recurrence of the disease .
the patient has received on - going follow - up under the care of the urology team , with 6-monthly ct scans which have thus far not shown any evidence of disease recurrence 24 months post - splenectomy .
the causes of isolated solid splenic lesions are wide and varied , and as such can present a diagnostic challenge .
a splenic mass without any history of malignancy suggests a primary lesion such as lymphoma , vascular tumours or infectious lesions .
any past or present history of malignancy however would lead to a high index of suspicion for a splenic metastasis . in the presence of isolated splenic metastasis
interestingly this has been described by mcgregor et al . who reported a clinically unidentified rcc diagnosed by fine needle aspiration of the spleen .
further differential diagnoses for isolated splenic mass include rarer lesions such as hamartoma and inflammatory pseudotumour , which can both clinically and radiologically mimic a metastatic tumour .
one should also consider the possibility of secondary involvement of the spleen through direct invasion , for example from a rcc .
splenic metastases were previously considered exceptionally rare , however more recent advances in radiological imaging and the increased follow - up of patients with cancer means that the rate of detection has increased .
an autopsy study found only 8% of 92 patients with secondary non - lymphoid splenic lesions at autopsy were symptomatic .
the majority of splenic metastases are part of a multi - visceral metastatic disease , and the detection is often made soon after diagnosis of the primary tumour ( mean duration after detection of primary tumour is 6.7 months ) , however this is often late in the course of disseminated disease .
there has however been a case of splenic metastasis 5 years after a radical prostatectomy for prostate carcinoma .
this case , along with recent advances in the knowledge of the metastatic process , makes it seem likely that late occurrence of solitary splenic metastases might develop from early blood - borne micrometastasis within the spleen after a period of clinical latency . in an autopsy study of splenic metastasis , the rate of dissemination to the spleen was highest from lung cancer , cutaneous malignant melanoma , and breast cancer , accounting for 24.6 , 15.8 , and 12.3% of all spleen metastases , respectively .
rcc has been reported to have spread to nearly every organ ; however the incidence of splenic metastasis is relatively low , with a 4.6% incidence in an autopsy study . to our knowledge
there have been only 8 cases of a splenic metastasis from a rcc that presented clinically and has been reported on , including our study [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ] .
the incidence of isolated splenic metastasis from any given primary is also particularly rare , with only 5.3% being found to be isolated at autopsy .
the reason for the relative rarity of splenic metastases might be explained by two main causes : ( 1 ) mechanical factors impeding the splenic implantation of blood - borne cancer cells , such as the constant flow of blood through the spleen and the rhythmic contraction of the splenic capsule , the sharp angle of the splenic artery branching from the coeliac trunk thus preventing large clumps of tumour cells from passing through , and the lack of afferent lymphatic vessels limiting lymphogenic metastases , and ( 2 ) the inhibitory effect of the splenic microenvironment on the growth of metastatic cells .
advances in imaging techniques have not only resulted in an increase in the detection of splenic lesions , but also in the cellular diagnosis using percutaneous biopsy ( using ultrasound or ct guidance ) [ 7 , 19 ] or endoscopic fine needle aspiration . given that a splenic metastasis is often found in the context of disseminated malignancy , it tends to have no clinical importance .
a splenectomy however can be indicated for palliative symptomatic relief , with reports of acceptable morbidity and improvements in quality of life .
they are often asymptomatic and picked up either incidentally or on surveillance imaging for previous malignancy .
a splenectomy is an effective and safe option for symptomatic relief and prevention of future complications .
 this report presents the case of a 70-year - old woman with a previous history of a left nephrectomy for renal cell carcinoma ( rcc ) , who developed general malaise and fatigue . 
 abdominal computed tomography demonstrated an enhancing 6  7 cm necrotic lesion in the lower pole of the spleen suggestive of a metastasis . 
 given the highly suspicious nature of the lesion we proceeded to splenectomy . 
 the tumour did not breach the splenic capsule , and there was no local diaphragmatic involvement . 
 the mass was concluded to be a true metastasis of the original rcc rather than local recurrence of the disease . 
 the causes of isolated solid splenic lesions are wide and varied , however a past or present history of malignancy should lead to a high index of suspicion for a splenic metastasis . 
 we report an extremely unusual case of spread from a rcc . 