dilatation of pulmonary arteries is a well - known clinical entity commonly encountered in many congenital and acquired heart lesions .
idiopathic dilatation of pulmonary arteries ( idpa ) was first recognized as a benign anomaly in 1923 by wessler and jaches .
the incidence of this disease is 6 cases per 1000 cases of congenital cardiac disorders .
diagnosis of idpa is made after excluding all possible causes that can induce pulmonary artery ( pa ) dilatation .
it is usually an incidental finding not fully explained by the patient symptoms and clinical condition .
treatment is usually not required as it is considered to be a benign condition , although literature on long - term follow - up is lacking .
a 68-year - old female presented with insidious onset gradually progressive shortness of breath from mmrc stage 1 to stage 3 for the last 10 years , which further increased over the past 2 months .
she had no associated history of a cough , fever , palpitations , chest pain , pedal edema , orthopnea , or paroxysmal nocturnal dyspnea . on clinical examination , her vitals included pulse rate 
there was no pallor , icterus , cyanosis , pedal edema , or raised jugular venous pressure .
5600/dl with a differential count of neutrophils  72% , lymphocytes  10% , eosinophils  1% , and monocytes  7% .
serum c - reactive protein level was normal ( 0.24 mg / dl ) with elevated serum brain natriuretic peptide levels ( 162 pg / ml ) .
anti - nuclear antibodies along with anti - neutrophil cytoplasmic autoantibody levels and thyroid function tests were within normal limit , and there was no evidence of infectious diseases such as tuberculosis or syphilis .
x - ray chest revealed mild cardiomegaly of the right ventricular ( rv ) type with mild right atrial dilatation and massive enlargement of the main pa with normal pulmonary vascular markings [ figure 1 ] .
( a ) chest x - ray showing dilated pulmonary artery , ( b ) contrast - enhanced computed tomography chest showing enlarged main pulmonary artery ( 49.75 mm ) , ( c ) contrast - enhanced computed tomography chest showing dilated left pulmonary artery ( 36.96 ) , ( d ) contrast - enhanced computed tomography chest showing dilated right pulmonary artery ( 37.76 mm ) , ( e ) contrast - enhanced computed tomography showing no evidence of pulmonary embolism , ( f ) computed tomography pulmonary artery reconstruction image showing dilated pulmonary artery echo - cardio - graphic findings revealed a normal - sized left ventricle and left atrium with 55% ejection fraction .
rv was dilated with adequate systolic function , with dilated right atrium , mild tricuspid regurgitation , and mild pa hypertension ( mean pa pressure 36 mmhg ) .
a computed tomography ( ct ) pulmonary angiography with high - resolution ct was done [ figures 1 and 2 ] which revealed dilated main pa with a maximum diameter of 49.75 mm , dilated right main trunk with a diameter of 37.76 mm , and dilated left trunk with a diameter of 36.96 mm .
pulmonary function test revealed restrictive airway defect with a normal diffusing capacity of carbon monoxide .
she was made to walk for 6 min in which she covered 216 meters without desaturation but had moderate fatigue and severe breathlessness at the end of the test .
high - resolution computed tomography sections of lung showing ground glass opacities in lung parenchyma cardiac catheterization was done through right femoral vein / right femoral artery approach .
rv angiogram showed the adequate systolic function of rv with normal pulmonary valve and massively dilated the main pa .
results of right heart catheterization on the basis of mild symptoms and pulmonary artery pressure ( pap ) < 30 mmhg , a massive dilation of pa could not be explained so the diagnosis of idpa was made after ruling out all possible causes .
kaplan et al . postulated it as mal - development of the entire pulmonary tree and congenital weakness of the arterial wall whereas assman thought of it as an unequal division of truncus arteriosus communis . in 1949 , greene et al . and associates established the following pathologic criteria for its diagnosis : 
 simple dilatation of the pulmonary trunk with or without involvement of the rest of arterial treeabsence of intra - cardiac or extracardiac shuntsabsence of chronic cardiac or pulmonary diseaseabsence of arterial disease , such as syphilis , or more than minimal atheromatosis or arteriosclerosis of the pulmonary vascular tree . 
 
simple dilatation of the pulmonary trunk with or without involvement of the rest of arterial tree absence of intra - cardiac or extracardiac shunts absence of chronic cardiac or pulmonary disease absence of arterial disease , such as syphilis , or more than minimal atheromatosis or arteriosclerosis of the pulmonary vascular tree . in 1960 , deshmukh et al . , presented report of 13 patients in whom right heart catheterization was performed aimed at elaborating its clinical and physiological aspects and to further draw attention to this anomaly .
they opined that normal pressure in the rv and pa should be introduced as the fifth criteria in the diagnosis .
our case showed massive dilatation of pa with no apparent intra- or extra - cardiac shunt or any significant heart or lung disease . on right heart catheterization ,
pap was only 28 mmhg which does not explain the massive dilatation of pa in our case thus confirming the diagnosis . in spite of the well - marked clinical , radiologic and electrocardiographic features ,
the absence of shunt , the normal relationship in cardiac chambers and normal oxygen saturation are important findings .
long - term prognosis of idpa is usually excellent compared to pathological dilatation of pa .
however not much data on long - term follow - up of these patients exist .
management is also not well established , and any patient with an apparent diagnosis of idiopathic pulmonary hypertension needs to be followed up for a long time to know its benign course .
our case adds to the existing literature and spreads physician awareness about this entity and its diagnosis , which should be established after ruling out all possible causes of pulmonary dilatation .
 idiopathic dilatation of pulmonary arteries ( idpa ) is a rare abnormality of pulmonary arteries , the reported incidence in literature being as low as 0.007% in autopsy samples . with the improvement in diagnostic modalities , 
 antemortem diagnosis of idpa has been increasingly established by excluding diseases that induce pulmonary arterial enlargement . here , 
 we present a rare case of idiopathic dilatation of the pulmonary artery admitted with shortness of breath where idpa was diagnosed as an incidental finding using computed tomography pulmonary angiography and cardiac catheterization . 
INTRODUCTION
CASE REPORT
DISCUSSION
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