pneumatosis intestinalis ( pi ) and portal venous gas ( pvg ) are individually worrying radiological signs .
both are associated with severe mesenteric ischaemia and when present with symptoms of abdominal pain have a mortality rate in excess of 75% .
however , both can exist either individually or concurrently without any underlying abdominal or systemic pathology .
we describe a rare scenario where pi , pvg and pneumoperitoneum were found in an asymptomatic patient .
a 78-year - old male presented to the surgical assessment unit , following an abnormal chest x - ray performed for a persistent productive cough with fever .
the on - duty radiologist identified that this patient had significant free air under the diaphragm on his erect chest x - ray , and contacted the general practitioner directly who in turn organized admission to the surgical services .
he reported a fever for 2 days prior to the time of presentation but denied further pyrexias in the previous 48 h. he still had an ongoing productive cough , but without chest pain or difficulty in breathing .
he drank 10 units of alcohol per - week and he was an ex - smoker with a 15 pack - year history . on examination ,
the patient had non - tender and soft abdomen with no distension , organomegaly and bowel sounds were present .
he had mild crepitations at the right lung base , but respiratory examination was otherwise unremarkable .
a ct scan demonstrated significant free intra - peritoneal air ( figs  13 ) .
circumferential and linear intra - mural gas within the small bowel was seen consistent with pi .
small locules of air were seen in close proximity to the liver which was suggestive of pvg in the peripheral portal system .
a faecal calprotectin level was also sent ; this was later found to be negative . 

figure  1:a coronal ct image of the abdomen taken at initial presentation , demonstrating free air under the diaphragm ( pneumoperitoneum ) and pvg , both marked on images . 

figure  2:an axial ct image of the abdomen taken at initial presentation , demonstrating pi marked on the image . 

figure  3:an axial ct image of the pelvis in lung view windows , taken at initial presentation clearly demonstrating intra - mural air within the bowel , marked on image .
a coronal ct image of the abdomen taken at initial presentation , demonstrating free air under the diaphragm ( pneumoperitoneum ) and pvg , both marked on images .
an axial ct image of the abdomen taken at initial presentation , demonstrating pi marked on the image .
an axial ct image of the pelvis in lung view windows , taken at initial presentation clearly demonstrating intra - mural air within the bowel , marked on image .
his observations remained stable , his abdominal examination remained unremarkable and an arterial blood gas was normal .
he discharged home with open access but was to re - attend in 48 h for repeat ct scan and re - evaluation .
this second scan demonstrated an increase within the intra - abdominal air , and the gas within the portal venous system became more prominent .
the patient remained asymptomatic , observations remained normal and repeat blood tests were unremarkable . the patient was discharged with follow - up in clinic with a consultant general surgeon . upon review , he remained well and was discharged from clinic .
this patient was reviewed again 2 months later when admitted for a separate admission under orthopaedics for the management of a fractured neck of femur following a mechanical fall .
he was discharged home from orthopaedics following the placement of a dynamic hip screw with an uneventful recovery .
pi is a rare radiographic finding with an incidence in the general population of 0.03% .
the mechanical theory states an increase in pressure in the bowel lumen , lungs or mediastinum causes gas to dissect through the serosal / mucosal bowel wall .
the bacterial theory states that gas - forming organisms enter the layers of the bowel wall .
other associations of secondary pi include malignancy , chemotherapy , trauma , mechanical bowel disorders , copd , liver - failure and post - endoscopy . where pi is identified the mortality rate is 44% , and historically the presence of pi has necessitated a laparotomy .
there is a rarer primary form of pi , referred to as pneumatosis cystoides intestinalis ( pci ) accounting for 15% of cases .
the mortality for pvg ranges between 75 and 90% . the most common cause for pvg is acute mesenteric ischaemia accounting for 64% of cases .
other associations include inflammatory bowel disease , acute intestinal obstruction , trauma , malignancy , chemotherapy , liver transplant and diverticulitis .
idiopathic pvg has been described but makes up 2% of cases [ 2 , 3 ] .
both pi and pvg have been described concurrently , most commonly in symptomatic patients with severe intra - abdominal necrosis .
a 2009 case series of 88 cases of pi / pvg established three distinct subgroups : mechanical , ischaemic and benign .
of 88 patients , 19 were identified with benign pi including 6 patients with both pi and pvg .
two had a history of malignancy , one with acute liver failure and one with copd .
nine patients who were identified with benign pi and/or pvg were placed under observation , all making an uneventful recovery .
thus a management algorithm for pi / pvg patients where patients are risk stratified into high- , medium- and low - risk groups was proposed , where low - risk patients are observed with medical treatment alone [ 4 , 5 ] .
pi can also be seen with pneumoperitoneum and it proposed that this is caused by the rupture of the intra - mural gas blebs .
it is important to state that this rupture does not represent a true bowel perforation through all layers of bowel wall .
most gas blebs exist within the submucosal and subserosal layers of the bowel but these blebs do not communicate with the lumen of the bowel .
this case demonstrates that both the rare findings of pci and pvg can present together in the well - asymptomatic patient .
this was made even more unusual as the patient had no risk factors for either of these structural abnormalities .
whilst rare this has been described in literature before . however , this patient also had a significant pneumoperitoneum on ct imaging along with these other signs making this case particularly unusual .
 pneumatosis intestinalis ( pi ) is defined as the presence of gas within the serosal or mucosal layer bowel wall . 
 this sign is usually found upon radiographic imaging and is most commonly secondary to acute gastro - intestinal ischaemia . 
 fifteen per cent of cases can present with a primary condition called pneumatosis cystoides intestinalis ( pci ) . 
 pci is usually a benign condition and patients are usually asymptomatic . 
 portal venous gas ( pvg ) or the presence / accumulation of free gas within the hepatic portal vein . 
 it is most commonly associated with acute bowel ischaemia , and when seen in the presence of ischaemia the mortality rate is between 75 and 90% . 
 other associations include mechanical causes ( e.g. obstruction ) , chemotherapy , liver transplant and diverticulitis . 
 benign pi has previously been described with pvg , but usually in the presence of other associated conditions such as aids , malignancy or chemotherapy . 
 some examples have been described without these associations , but not with free intra - peritoneal air . 
 we describe a case of pci and pvg with pneumoperitoneum , investigations and ongoing management . 
INTRODUCTION
CASE REPORT
DISCUSSION
CONFLICT OF INTEREST STATEMENT