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Paper text:
haemangiomas are the most common benign liver neoplasm and result from ectatic growth of the vasculature
. these lesions can grow to a significant size and are referred to as giant haemangiomas once larger than 5 cm . despite the absence of invasive or metastatic potential , hepatic haemangiomas can result in pain , obstructive symptoms , rupture with life threatening haemoperitoneum or a consumptive coagulopathy known as kasabach  merrit syndrome .
consensus agreement on the indications for surgical resection , other than for symptomatic lesions , including for giant haemangioma , is lacking at present .
there is a paucity of available literature outlining the behaviour of haemangiomas during pregnancy , however female sex hormones have been implicated in their pathogenesis and growth .
the nature and extent of this relationship is yet to be fully elucidated . on the other hand ,
the diagnosis of a symptomatic giant haemangioma during pregnancy presents a dilemma because the safety of neither conservative nor surgical resection has been rigorously investigated . at our centre ,
a 30-year - old g2p0m1 female underwent resection of a symptomatic giant hepatic haemangioma during the second trimester without any complication .
an otherwise well 30-year - old female presented to her general practitioner complaining of intermittent right upper quadrant discomfort over the preceding months .
the patient was referred to hospital and ct imaging confirmed a pedunculated giant hepatic haemangioma ( 13.8 cm  10.2 cm  7.4 cm ) attached to segment 4 of the liver ( figs 1 and 2 ) .
two smaller intra - parenchymal haemangiomas in segment 6 and 8 were also identified and measured 0.5 cm and 1.3 cm , respectively . despite a negative urine beta hcg test at the time of ct scanning , she was subsequently found to be pregnant .
false negative results such as this are reported to occur , especially in the early luteal phase   when the urine hcg may not have reached the diagnostic threshold .
approximately 1 year prior , she had ceased the combined oral contraceptive after taking it for 10 years and was planning to conceive
. 
 figure 1:coronal ct image in the portal venous phase demonstrating the large exophytic haemangioma . 
 figure 2:axial ct image in portal venou phase at level slightly inferior to aortic bifurcation demonstrating the peripheral nodular enhancement of the haemangioma .
axial ct image in portal venou phase at level slightly inferior to aortic bifurcation demonstrating the peripheral nodular enhancement of the haemangioma . on first review in our clinic
she was counselled by a consultant liver surgeon and obstetrician about the available management options and associated risks .
the surgical options discussed included ; close observation throughout pregnancy and elective resection post - partum , termination of pregnancy followed by resection or resection during the second trimester of pregnancy .
our patient decided to have the tumour resected whilst pregnant due to the concern of rupture , accepting the risks of surgery to herself and the foetus .
the operation was scheduled for the second trimester as this is the period in which subsequent miscarriage or preterm labour are least likely .
the resection was performed at 18 weeks gestation under general anaesthesia via a small upper midline incision . upon entering the peritoneal cavity the exophytic haemangioma ( fig .
this allowed removal with minimal disruption of liver parenchyma , major vasculature or bile ducts .
minimal blood loss occurred and operating time was approximately 1 h. the smaller intra - parenchymal lesions were not resected as they were not the likely cause of her symptoms and represented a lower risk of rupture .
intraoperative foetal monitoring was not indicated due to the pregnancy still being in the previable phase
. 
 figure 3:intraoperative image demonstrating the exophytic nature of the haemangioma and relevant anatomical structures .
obstetric examination in the immediate post - operative period was consistent with a healthy foetus and the patient was discharged from hospital on the third post - operative day .
histopathological examination of the tumour confirmed a haemangioma weighing 412 g. the patient received outpatient follow - up and did not experience any surgical or obstetric complications .
a healthy infant was delivered at term via an elective caesarean section due to maternal request .
there is little available literature describing the outcome of liver haemangioma resection during pregnancy . to our knowledge
, the only available publication is an isolated case report of a successfully resected giant haemangioma at 16 weeks gestation due to kasabach  merit syndrome .
the scarcity of data may be representative of how infrequently this operation is performed during pregnancy .
both pregnancy and hormonal therapy , including the oral contraceptive , have been associated with haemangiomas enlargement .
rapid growth   and haemorrhagic complications   have been reported but a recent small case series ( four patients , seven pregnancies ) found that these tumours can be safely observed during pregnancy . a larger observational cohort study in non - pregnant individuals found that haemangioma resection can be justified due to minimal morbidity and no mortality in the 13 patients who underwent surgery .
however , these authors also found that no tumours under 5 cm increased in size or ruptured in patients who received conservative management . obviously , extrapolation of these findings to our patient would be misguided as the large peripheral exophytic tumour was > 5 cm and she was pregnant .
spontaneous rupture is the complication most feared because this is associated with a mortality rate approaching 80% .
a recent large study has estimated that the rupture rate of giant liver haemangioma is 3.4% with peripherally located and exophytic lesions being at higher risk .
accelerated growth , increased intra - abdominal pressure and direct contact with the gravid uterus are all plausible mechanisms for spontaneous rupture or worsening symptoms during pregnancy .
intrapartum rupture of liver haemangiomas has been reported , supporting the notion that increased intra - abdominal pressure may be a causative factor .
our patient 's tumour was assessed as being high risk for complications during pregnancy due to its size , exophytic nature and subumbilical position .
therefore , we felt that the risks associated with surgery were justified in this case as spontaneous or intrapartum rupture could be an unsurvivable event .
to our knowledge , this is only the second case report of a successful hepatic haemangioma resection during pregnancy .
the natural history of these lesions during pregnancy is incompletely understood and resection should be considered if worsening symptoms or the clinical concern for rupture is significant .
an interdisciplinary approach that involves surgical , anaesthetic and obstetric specialists is required to perform this procedure safely , and a good overall result for mother and child is possible .
liver haemangiomas are consistently reported to be the commonest benign liver tumours and are most often incidental findings in asymptomatic individuals . 
 large lesions can become symptomatic , spontaneously rupture or result in a consumptive coagulopathy known as kasabach  merrit syndrome . 
 it is believed that the female sex hormones , particularly oestrogen , have an influence on haemangioma development and growth . 
 the optimal management of large haemangiomas during the hyperoestrogenic state of pregnancy is poorly described in the current literature . to our knowledge , we describe only the second case of a giant hepatic haemangioma resection during pregnancy .