differential diagnosis for a solitary pleural mass may include malignant or benign pleural tumors or mass related to ribs or chest wall . the metastatic involvement of the pleura is much more common than the primary pleural tumors . loculated fluid in the pleural cavity may also radiologically present as a solitary pleural mass , and is referred to as a pseudotumor .  here , we present a case of a 57-year - old male who presented with hemoptysis of 4 years duration and a gradually increasing pleural mass on chest x - ray ( cxr ) who developed life - threatening post - operative complication after thoracotomy , which was performed to rule out malignancy . a 57-year - old male , non - smoker , non - alcoholic and with no co - morbidities or any significant past medical illness presented with complaints of mild , off and on hemoptysis and heaviness in the right chest for 4 years . he was diagnosed to have a right chest mass that had been increasing in size radiologically for the last 4 years . on examination , he was conscious , oriented and afebrile with a respiratory rate of 16/min , pulse of 74/min , blood pressure 120/80 mmhg and oxygen saturation of 97% on room air . systemic examination was unremarkable except for reduced breath sound on right side of the chest . inr was 1.13 and aptt was 30.2 s with a control of 29.0 s. cxr showed dense rounded pleural - based opacity in the right lower zone . ultrasound revealed mild hepatomegaly and right lower pleural mass with no associated effusion . computed tomography ( ct ) scan chest showed non - enhancing right pleural mass with specs of calcification compressing the superior surface of the liver [ figure 1 ] . computed tomography scan of the chest showing non - enhancing right pleural lesion abutting the anterior and lateral chest wall causing passive atelectasis of the underlying lung . mild pleural thickening is also noticed one year back , ct - guided fine needle aspiration cytology ( fnac ) was suggestive of an organized hematoma . about 1 month back , a trucut biopsy had revealed dense fibrous tissue with marked hyalinization and inflammation with no evidence of granuloma or malignancy . serial cxrs showed progressive enlargement of the mass and , hence , a provisional diagnosis of a tumor of fibrous origin possibly undergoing malignant change was made . therefore , a diagnostic and therapeutic exploratory thoracotomy was performed , which revealed a large , thick - walled hematoma in the pleural space adherent to the lung . complete excision of mass was carried out and an intercoastal tube ( ict ) was placed . the patient continued to bleed through ict at a rate of 200300 ml / h . he was managed with intravenous fluids , tranexamic acid , aprotinin , vitamin k and activated factor vii in a dose of 7.2 mg , which was given empirically when bleeding could not be controlled with other medical measures . despite multiple blood and blood product transfusions , bleeding did not stop . , more than 1 l of blood was seen in the pleural cavity with diffuse small oozes and with no evidence of any surgical bleed . after re - exploration , bleeding through ict significantly reduced to 50 ml / h . histopathology of the pleural mass revealed fibrocollagenous pleural tissue with ulceration of mesothelial lining and foci of fibrin deposition [ figure 2 ] , suggestive of an organizing hematoma . histopathology specimen of the pleural mass showing blood clots and few newly formed blood vessels ( 10 hematoxylin and eosin stain ) during the fourth to seventh post - operative days , the patient 's general condition gradually worsened . there was progressive worsening of cxr suggestive of collection of clots on the right side , even though ict was not draining anything . the hemoglobin continued to drop and he was unable to maintain adequate oxygen saturation with high - flow oxygen and , hence , was started on bipap support . he was again transfused packed cells and blood products . on the seventh post - operative day , factor viii levels were reported to be 103% of normal ( 60150 ) , whereas factor ix ( functional ) was only 24.5% . factor ix concentrate 1800 iu once daily was continued for the next 4 days , after which repeat assay was 80% of normal . dose of factor ix was gradually reduced to 600 iu and then stopped after 7 days . the patient continued to improve and was discharged on the 16 post - operative day and did not develop any further complications even after 6 months of follow - up . complete familial work - up was done and his daughter and granddaughter were both found to be carriers for hemophilia b. hemophilia is a genetic bleeding disorder that is inherited in a sex - linked recessive pattern . two most common forms are hemophilia a and b , which are caused by a defect or deficiency of clotting factors viii and ix , respectively . as these disorders are x - linked recessive , only males exhibit the disease and females are carriers . worldwide , the incidence of hemophilia a and b is about 1520 per 100,000 males . hemophilia a is almost five - times more common , with the reported incidence of hemophilia b or christmas disease being around 1 in 60,000 . the underlying pathophysiology of hemophilia b involves inadequate generation of thrombin , which causes reduced clot formation and reduced clot stabilization . clinically , it commonly manifests as mucosal bleeding or as spontaneous or post - traumatic bleeding typically into the joints or deep muscles . pulmonary involvement is rarely reported.[57 ] the age at diagnosis is related to the level of factor ix activity . only a few cases of hemophilia b with primary pulmonary involvement have been reported in the literature.[57 ] odwyer and deloughery reported a case of hemophilia b with pulmonary hemorrhage with bleeding inside a bulla mimicking a lung neoplasm . also reported a case of hemophilia b with hemothorax , which also developed a massive post - operative bleed after video - assisted thoracic surgery with lung decortication was performed to manage hemothorax . significantly prolonged aptt may typically suggest a diagnosis of hemophilia , but aptt may be normal or only minimally prolonged in patients with less - severe disease , which may make the diagnosis more challenging , as in our case . hence , massive post - operative bleeding was totally unsuspected in our case . hemophilia b has been classified as mild , when activity is between 5 and 30% , moderately severe when activity is between 1 and 5% and severe when it is less than 1% . according to this , our patient may qualify as having a mild disease with factor ix activity of 24.5% . this case stresses upon the fact that hereditary bleeding disorders may be diagnosed even in late adulthood with atypical presentations . moreover , hemophilia b may present with normal aptt levels , making the diagnosis even more difficult .
a 57-year - old male presented with hemoptysis of 4 years duration and a gradually increasing pleural mass on chest x - ray . 
 the mass was causing pressure effects on the liver and the lungs . to rule out malignancy , 
 thoracotomy was performed , which revealed large , thick - walled hematoma . 
 complete excision of mass was performed . 
 post - operative course was complicated by massive pleural bleeding requiring massive blood transfusions and re - exploratory thoracotomy . 
 subsequent tests revealed factor ix deficiency and , hence , he was managed with recombinant factor ix concentrate . 
 this case stresses upon the fact that hereditary bleeding disorders may be diagnosed even in late adulthood with atypical presentations such as pseudotumor in pleural space . moreover 
 , hemophilia b may present with normal aptt levels making the diagnosis even more difficult .