we encountered a woman with a preexisting large focal nodular hyperplasia ( fnh ) of the liver , persisting during two separate pregnancies .
her elevated serum -glutamyltransferase and alkaline phosphatase levels before pregnancy were reduced during both pregnancies , but returned to prepregnancy levels after delivery .
focal nodular hyperplasia ( fnh ) is a benign lesion of the liver that is not uncommon in adults and is frequently observed in healthy individuals .
it is unclear , however , whether pregnancy in women with fnh increases the risks of fnh growth and complications or alters hepatic function in patients .
we encountered a woman with a large fnh , who experienced two pregnancies and delivered healthy infants at term uneventfully .
the courses of her pregnancies and the effects of pregnancy on fnh , including lesion size and hepatic function were evaluated at the same institution .
the patient was a 25-year - old , gravida 0 , para 0 , female , who had been followed up since the age of 18 years at the internal medicine outpatient ward of our institution because of a large fnh . at the age of 13 years
, a nodule measuring 8 cm was observed in the patient , at a medical institution near her residence .
a biopsy was performed , and on histological analysis of the specimen , she was diagnosed with fnh . because the nodule was located near the hepatic hilus , surgical intervention was not performed . at the age of 25 years , the patient married and moved near our hospital . an mri taken before her first pregnancy showed that the nodule was 11 cm in diameter ( figs.1a and 2a ) .
a high intensity area was observed at the center of the lesion , a finding compatible with central scar tissue , with a moderately high intensity area observed at the surface of the lesion .
( c ) during her second pregnancy at 34 weeks of gestation . before becoming pregnant ,
her liver function tests showed that her serum aspartate aminotransferase ( ast ) and alanine aminotransferase ( alt ) concentrations were in the normal ranges , but her -glutamyltransferase ( ggt ) and alkaline phosphatase ( alp ) concentrations were elevated , to 651 iu / l and 407 u / l , respectively . after conceiving , she was referred by her physician to our outpatient ward at 9 weeks of gestation . during her first pregnancy ,
her serum concentrations of liver enzymes decreased to the normal range without any medication ( fig.3 ) .
magnetic resonance imaging performed at 37 weeks of gestation showed that the size of the fnh was unchanged , with no signs of bleeding or degeneration of the lesion ( figs.1b and 2b ) .
the concentrations of aspartate aminotransferase ( ast ) , alanine aminotransferase ( alt ) , lactate dehydrogenase ( ldh ) , alkaline phosphatase ( alp ) , and -glutamyltransferase ( ggt ) are shown in u / l .
, she delivered a normal , healthy female infant , weighing 3084 g and with 1 and 5 min apgar scores of 8 and 9 , respectively , by vaginal delivery .
her postpartum recovery was normal , except that her serum ggt and alp concentrations became elevated , returning to their prepregnancy levels .
this pregnancy was also uneventful ( figs.1c , 2c , and 3 ) and , at 40 weeks of gestation she delivered a normal , healthy male infant , weighing 3130 g and with 1 and 5 min apgar scores of 9 and 10 , respectively , by vaginal delivery .
her postpartum course was again uneventful , and both mother and child were discharged after 5 days .
the size of the fnh remained the same as before her first pregnancy , despite two pregnancies and deliveries . during both pregnancies , her serum concentrations of liver enzymes
after conceiving , she was referred by her physician to our outpatient ward at 9 weeks of gestation . during her first pregnancy ,
her serum concentrations of liver enzymes decreased to the normal range without any medication ( fig.3 ) .
magnetic resonance imaging performed at 37 weeks of gestation showed that the size of the fnh was unchanged , with no signs of bleeding or degeneration of the lesion ( figs.1b and 2b ) .
the concentrations of aspartate aminotransferase ( ast ) , alanine aminotransferase ( alt ) , lactate dehydrogenase ( ldh ) , alkaline phosphatase ( alp ) , and -glutamyltransferase ( ggt ) are shown in u / l . her first course of pregnancy was uneventful . at 39 weeks , she delivered a normal , healthy female infant , weighing 3084 g and with 1 and 5 min apgar scores of 8 and 9 , respectively , by vaginal delivery .
her postpartum recovery was normal , except that her serum ggt and alp concentrations became elevated , returning to their prepregnancy levels .
this pregnancy was also uneventful ( figs.1c , 2c , and 3 ) and , at 40 weeks of gestation she delivered a normal , healthy male infant , weighing 3130 g and with 1 and 5 min apgar scores of 9 and 10 , respectively , by vaginal delivery .
her postpartum course was again uneventful , and both mother and child were discharged after 5 days .
the size of the fnh remained the same as before her first pregnancy , despite two pregnancies and deliveries . during both pregnancies , her serum concentrations of liver enzymes
focal nodular hyperplasia is a common type of hepatic mass in adults , with an incidence of approximately 3% .
we encountered a woman who had fnh prior to her first pregnancy and followed her throughout two courses of pregnancy .
in contrast , the serum concentrations of liver enzymes were decreased during both pregnancies , and returned to their prepregnancy levels soon after the deliveries .
a previous study described the effects of 41 pregnancies on fnh in 37 women , finding that the size of the fnh was not affected by pregnancy .
another study   evaluating the effects of pregnancy on fnh size in patients found that the mean tumor size before pregnancy was 58.5  22.7 mm .
tumor size remained constant in seven of these 20 patients ( 35% ) and declined in 10 ( 50% ) .
however , fnh size in multiparous women was assessed using a questionnaire , not by actual measurement .
furthermore , that study evaluated only lesion size , not changes in serum enzyme concentrations . in our patient ,
the fnh was > 11 cm in diameter , the largest fnh reported to date , and its size was not affected by either of her two pregnancies .
there have been no reports on changes in the serum concentrations of liver enzymes during pregnancy in women with fnh .
in contrast , serum alp and ggt values , which were elevated before and after her pregnancies , decreased to normal levels during her pregnancies . alp and ggt are enzymes present in the cell membranes of the bile duct , gall bladder , pancreas , and kidneys .
serum concentrations of alp elevate by placental origin and ggt are not affected in pregnancies in women without fnh , but were shown to be higher in few pregnant women ( < 1% ) with intrahepatic cholestasis .
pregnancy may alter the results of liver function tests , with placental steroids playing a role . during pregnancy , the production of placental steroids increases the serum estrogen and progesterone concentrations compared with the nonpregnant state .
for example , a 9-year study of 216 women in france showed that neither the size nor the numbers of fnh lesions are influenced by oral contraceptive use .
although estrogen receptors were shown to be present in the cytosol and nuclei of hepatic cells including the tissue of fnh , few estrogen receptors are present on the cell surface .
estrogen and progesterone affect the mrna expression and activity of cyps ( cytochrome p450 ) in primary human hepatic cells , as shown in a recent study .
these findings potentially provide a basis to understand the mechanism of altered drug metabolism during pregnancy .
however , further studies are needed to investigate the lowering of serum alp and ggt in fnh . in conclusion ,
we have described here a single patient with fnh of the liver complicating pregnancy and postpartum delivery twice over a 4-year observation period .
fnh size was not affected by pregnancies , whereas liver function test results improved , allowing these enzymes to return to their prepregnancy levels after deliveries .
lesion size and abnormally elevated serum liver enzyme concentrations are not indicated for surgery in pregnant women with asymptomatic fnh .
our findings indicate that women with large fnh , even those with elevated serum liver enzymes , should not be discouraged from pregnancy .
 key clinical messagewe encountered a woman with a preexisting large focal nodular hyperplasia ( fnh ) of the liver , persisting during two separate pregnancies . 
 fnh size was not affected by either pregnancy . 
 her elevated serum -glutamyltransferase and alkaline phosphatase levels before pregnancy were reduced during both pregnancies , but returned to prepregnancy levels after delivery . 
Key Clinical Message
Introduction
Case History
Differential diagnosis, investigations, and treatment
Discussion
Conflicts of Interest