the following case report highlights a potentially life threatening complication of undertaking an incision biopsy on a soft tissue tumour , namely surgically uncontrollable haemorrhage from an unsuspected vascular lake .
the case report demonstrates the value of interventional radiology for acute bleeding and radiotherapy for more chronic tumour bleeding .
a 75 year old male presented with a 3 month history of painful progressive left buttock swelling and non - productive cough .
past medical history included carcinoma of the prostate 5 years previously , which had been treated with surgery and radiotherapy .
examination revealed a fixed 10 by 10 cm mass in the left buttock extending over the sacro - iliac joint .
a pleural aspiration cytology confirmed a malignant effusion , although did not differentiate the cell type .
the pelvic mri scan demonstrated a large 10 x 10 x 5 cm heterogeneous lesion in the left buttock , occupying much of the posterior portion of the gluteus maximus and invading the iliac bone and sacrum .
the primary lesion was not operable and the presence of the malignant effusion denoted stage 4 disease , ( t2 , n0 , m1 ) .
percutaneous needle core biopsy of the lesion was inconclusive and incision biopsy was requested after drainage and talc pleurodesis of the pleural effusion . at the time of incision biopsy the capsule of the lesion
this resulted in profuse bleeding from a deep , fresh blood filled , cavity within the cystic tumour . a large vascular lake in the centre of the tumour was evident with a significant vascular flow rate .
the cavity was therefore tightly packed with haemostatic material and firm pressure applied to the wound , causing partial cessation of the haemorrhage .
full surgical control of the bleeding was not possible due to the fact that the tumour was in - operable and the feeding vessels originated from the internal iliac vessels running through the invaded bone of the ileum .
angiography revealed a tumour blush in the gluteal region supplied by the median sacral artery and the posterior division of the internal iliac artery ( iia ) .
the iia was catheterised revealing multiple feeding branches with extravasation from one ( figure 1 ) .
angiograms pre - embolisation with histo - acryl angiograms post - embolisation with histo - acryl over the ensuing 3 weeks , despite the initial successful embolisation the patient haemorrhaged on a further 2 occasions despite pressure dressings to the wound area . on both of these occasions
on each occasion , a different set of feeding vessels was noted to be bleeding and was embolised .
histology from the incision biopsy revealed a diagnosis of epithelioid angiosarcoma ( figure 2 ) which is known to be associated with the development of vascular lakes .
( cd31 immunohistochemistry : immunoperoxidase , original magnification x100 ) to prevent the occurrence of further haemorrhage , the patient was given a course of radiotherapy ( 30gy in 10 treatments over 14 days ) .
palliative chemotherapy to control respiratory symptoms from the pleural effusion was declined and the patient died 6 months after initial presentation .
the epithelioid phenotype of angiosarcoma was first described in 1976 by rosai and colleagues who documented cases of cutaneous angiosarcomas .
it was later documented by fletcher and colleagues in 1991 who described deeper lesions found in the soft tissues where they are now most commonly found .
( 1 ) epithelioid angiosarcomas are rare , high - grade , malignant , vascular tumours , which have an aggressive course and tend to recur locally , spread widely , and have a high rate of lymph node and systemic metastases.(2 ) it often presents in middle - aged and elderly males with a peak incidence in the seventh decade of life .
prognosis for these types of tumours is very poor with death usually occurring from 6 months to 2 years after presentation .
epithelioid angiosarcomas have been described arising in various soft tissues around the body and are most often metastatic in origin .
histologically these tumours consist of solid and infiltrative sheets of epithelioid cells characterised by large , oval to round cells with abundant eosinophilic cytoplasm , vesicular nucleus and eosinophilic nucleolus.(3 ) in most cases there are vascular channels or cystically dilated spaces .
vascular lakes are therefore a common finding associated with these types of sarcoma . a distinctive  starry - sky  histological pattern has also been reported in epithelioid angiosarcomas .
immunohistochemically the neoplastic cells show positivity for endothelial cell markers such as cd31 , cd34 , factor viii - related antigen , and vimentin.(4 - 5 ) due to cytokeratin expression and epithelioid growth pattern these tumours can occasionally be misdiagnosed as carcinomas .
endothelial differentiation can be confirmed ultrastructually by the presence of weibel - palade bodies , intermediate filaments and basal lamina .
intracytoplasmic vacuoles containing red blood cells are often present in some cells.(4 ) irradiation of soft tissues for the treatment of various primary cancers is well documented as a cause for several types of sarcoma . as in this case
, the patient had undergone a course of radiotherapy for prostate cancer several years prior to presenting with the pelvic sarcoma and this therefore may have been the causative factor .
other risk factors for the development of angiosarcomas include carcinogens , chronic lymphoedema and hormonal status .
however one such case documented a lesion of the mons pubis 4 years following radiotherapy for vulval carcinoma.(5 ) angiography and tumour embolisation is a well established treatment of tumours both pre- and post - operativley .
tumour embolisation may be carried out for acute bleeding from tumour vessels , and to reduce the blood supply to tumours prior to surgery .
treatment usually consists of delivering one or two fractions of 5 - 8 gy each on successive days .
 epithelioid angiosarcoma is a rare , highly malignant tumour with a poor prognosis . 
 we present the case of a 75 year old man who underwent an incision biopsy to diagnose the soft tissue tumour and suffered from surgically uncontrollable haemorrhage . 
 the case report demonstrates the value of interventional radiology for acute bleeding and radiotherapy for more chronic tumour bleeding . 
INTRODUCTION
CASE REPORT
DISCUSSION