Mediastinal pancreatic pseudocyst masquerading as diffuse alveolar haemorrhage
- Heather Lynn Clark ,
- Lijo C Illipparambil and
- Sandhya Khurana
- Department of Medicine, University of Rochester Medical Center, Rochester, New York, USA
- Correspondence to Dr Lijo C Illipparambil; lijo_illipparambil@urmc.rochester.edu
Abstract
Pancreatic pseudocyst formation with extension into the mediastinum is an uncommon complication of pancreatitis that can result in numerous pulmonary and cardiac complications. We present a case of a 56-year-old man with a history of recurrent pancreatitis who presented with haemoptysis. His initial workup was consistent with diffuse alveolar haemorrhage for which he was treated with glucocorticoids. After failure to improve, further imaging demonstrated a complex fluid collection in the mediastinum consistent with extension of his pre-existing pancreatic pseudocyst, leading to erosion into the right lower lobe of the lung. This case highlights a rare pulmonary complication of pancreatitis and underscores the importance of proper identification of this condition to guide successful management.
Background
Acute pancreatitis is a common disease affecting thousands of patients annually and is associated with significant morbidity and healthcare utilisation.1 In addition to abdominal complications such as pseudocyst formation, it is also associated with several pulmonary complications including acute lung injury/acute respiratory distress syndrome, pleural effusion and pulmonary embolism.2 Rarely, pancreatic pseudocysts can extend into the thoracic cavity, often through openings in the diaphragm, and invade the mediastinum, pleural or pericardial space.3 Pancreatic-pleural-pulmonary fistula should be considered in patients with a history of recurrent or severe pancreatitis and symptoms of dyspnoea, dysphagia or chest pain.4 5 Infection of the pseudocyst fluid, pleural effusion or alveolar haemorrhage, as well as more severe complications such as airway compression, congestive heart failure and cardiac tamponade can occur.6–8 Haemoptysis is a rare complication of pancreatitis, due to the formation of a pancreatic-pulmonary fistula and erosion of pancreatic fluid into the lung parenchyma and the airways.9 10
Case presentation
A 56-year-old man presented to the emergency department with acute-onset right-sided chest pain, haemoptysis and shortness of breath. This was his third presentation for haemoptysis in 2 months. He initially expectorated coin-sized blood-tinged sputum with progressive increase in volume to approximately 200 mL of thin bloody sputum daily. The medical history was significant for recurrent acute pancreatitis requiring frequent hospitalisation, alcoholic cirrhosis, untreated hepatitis C infection and recently diagnosed portal vein thrombosis treated with apixaban. Prior abdominal imaging had demonstrated acute pancreatitis and large-volume ascites but no organised fluid collections. The patient endorsed half pack-per-day tobacco smoking, as well as active alcohol and cocaine use.
Physical examination revealed a chronically ill-appearing cachectic man. He was mildly tachycardic but otherwise normotensive and oxygenating well on room air. Lung examination was unremarkable with good air movement and clear on auscultation. Abdominal examination was significant for diffuse tenderness and guarding on palpation.
Laboratory data and imaging findings
Diagnostic evaluation for aetiology of haemoptysis and alveolar haemorrhage was unrevealing as summarised in table 1. Prior multiple CT chest imaging studies had revealed a right lower lobe (RLL) infiltrate and a right posterior mediastinal fluid collection, improved on subsequent imaging. Bronchoscopic evaluation was also completed during a prior hospitalisation, and bronchoalveolar lavage (BAL) findings were suggestive of alveolar haemorrhage. Initially, haemoptysis was attributed to anticoagulant use for his portal vein thrombus and inhalation of cocaine. The haemoptysis, however, persisted after discontinuation of apixaban, and treatment with systemic corticosteroids was initiated. He had received packed red blood cell transfusions intermittently throughout the course of his illness. With the steroid therapy, the haemoptysis improved and he was discharged. The patient, however, did not continue corticosteroids after discharge from the hospital and now had returned with continuing haemoptysis and new right-sided chest pain.
Negative or normal laboratory diagnostic studies for alveolar haemorrhage in our patient
| Autoimmune | Infectious | Others |
| ANA | IGRA | NT-pro-BNP |
| ANCA | HIV | Creatine kinase |
| Anti-PR3 Ab | Leptospirosis IgM | Urine microscopy |
| Anti-MPO Ab | Mycoplasma NAAT | IgG |
| dsDNA Ab | Legionella Ag (urine) | |
| Rheumatoid Factor | Streptococcus pneumoniae Ag (urine) | |
| C3, C4, CH50 | Hepatitis C PCR | |
| Anti-cardiolipin Ab | Procalcitonin | |
| Cryoglobulin panel | ||
| Beta-2-glycoprotein IgG/IgM |
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ANA, antinuclear antibody; ANCA, anti-neutrophil cytoplasmic antibody; dsDNA, double-stranded DNA; IGRA, interferon gamma release assay; NAAT, nucleic acid amplification test; NT-pro-BNP, N-terminal pro-brain natriuretic peptide.
His routine laboratory studies on this admission (box 1) demonstrated elevated amylase and lipase, similar to his prior admissions. He additionally had continued anaemia, neutrophilic leukocytosis and thrombocytosis.
Routine laboratory data on admission
Laboratory data (normal value)
INR, 1.4 (0.9–1.1)
Amylase, 13 410 (28–100) U/L
Lipase, 4688 (13-60) U/L
AST, 62 (0–50) U/L
ALT, 26 (0–50) U/L
WBC, 25.5 (4.2–9.1) x 109/L
91% neutrophils, 3.5% lymphocytes, 3.0% monocytes, 0.8% eosinophils
Hgb, 80 (137–175) g/L, Hct, 24% (40%–51%)
Platelets, 760 (150–330) x 109/L
His chest X-ray revealed a new right-sided pneumothorax and a persistent right basilar opacity (unchanged from prior study).
He underwent a CT of the abdomen and pelvis on admission that revealed a new large organised peripancreatic fluid collection, cirrhotic changes in the liver, known left portal vein thrombosis and cholelithiasis.
CT of the chest, completed after small-bore chest tube placement for right pneumothorax, showed trace right hydropneumothorax, increased alveolar and ‘crazy paving’ opacities in the RLL, and resolved pneumomediastinum.
The patient’s haemoptysis did not respond to treatment with broad-spectrum antibiotics or reinitiation of high-dose corticosteroids. Follow-up chest and abdominal imaging demonstrated a complex posterior mediastinal fluid collection extending into the right pleural space and RLL with contained air. RLL pulmonary arteries and veins were coursing close to the collection with no active extravasation of intravenous contrast. Extensive reticulonodular opacities were noted bilaterally (figure 1A,B). Abdominal imaging showed a peri-hiatal fluid collection adjacent to the right hydropneumothorax and a dominant pseudocyst in the left upper quadrant and central abdomen (figure 2A,B), consistent with a diagnosis of pancreatic pseudocyst invasion into right mediastinum and right lung base.
CT of the chest from current admission. (A) Lung windows showing extensive bilateral infiltrates. (B) Mediastinal windows showing complex fluid collection (arrow).
CT of the abdomen with contrast from current admission showing (A) peri-hiatal fluid collection adjacent to right hydropneumothorax (arrow) and (B) left upper quadrant pseudocyst (long arrow) and peri-hiatal fluid collection (short arrow).
Treatment
After discussion with infectious disease, gastroenterology and surgical consultants, CT-guided placement of 12-French catheter into the abdominal fluid and 10-French catheter into the mediastinal fluid collection was performed. Fluid characteristics from both collections were similar, including elevated fluid amylase level. Microbiological cultures were positive for vancomycin-resistant Enterococcus faecium and Candida albicans (table 2). Antimicrobial therapy was tailored in consultation with infectious disease colleagues. Enteral nutrition was attempted, but the patient was unable to tolerate this due to severe abdominal pain. Total parental nutrition (TPN) was therefore started with complete bowel rest. The corticosteroids were rapidly tapered. He subsequently underwent endoscopic retrograde cholangiopancreatography (ERCP) that revealed a 3 cm stricture of the pancreatic duct (PD) without evidence of overt PD leak (figure 3). A 7 Fr × 6 cm PD stent was placed. An additional 14-French abdominal drain was placed for enlarging abdominal pseudocyst.
Mediastinal and abdominal fluid characteristics
| Mediastinal fluid | Abdominal fluid | |
| Gram stain | Gram-positive cocci in pairs | Gram-positive cocci in pairs/chains |
| Cell count | 34 965 NC cells (predominantly PMNs); intracellular bacteria | 3111 NC (predominantly PMNs); intracellular and extracellular bacteria |
| Aerobic culture | Enterococcus faecium (VRE) 4+; Candida albicans 4+ | E. faecium (VRE) TNTC; C.albicans <1 CFU/mL |
| Anaerobic culture | NG | NG |
| Fungal stain and culture | Fungal elements/C. albicans 3+ | ND |
| AFB smear and culture | NEG/no result | ND |
| Legionella culture | NEG | ND |
| Cytology | Acute inflammation | Acute inflammation |
| Protein | 1.4 g/dL | 1.0 g/dL |
| Albumin | <1.0 g/dL | ND |
| Glucose | <5 mg/dL | 18 mg/dL |
| LDH | 222 U/L | 489 U/L |
| Amylase | >30 000 U/L | >30 000 U/L |
| Lipase | ND | >6000 U/L |
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AFB, acid-fast Bacilli; CFU, colony-forming unit; LDH, lactate dehydrogenase; NC, nucleated cells; ND, not done; NG, no growth; PMCs, polymorphonuclear cells.
Pancreatogram on initial endoscopic retrograde cholangiopancreatography demonstrating no pancreatic duct leak.
Outcome
His haemoptysis resolved and abdominal pain improved after drainage, and drains were subsequently removed. His weight and nutritional status improved with TPN, and he was successfully transitioned to enteral diet over several months. He was discharged from the hospital. He has undergone two additional ERCPs with replacement and upsizing of the PD stent, which currently remains in place.
Discussion
Pancreatitis is a common disease that affects thousands of patients every year. Mediastinal extension of pancreatic pseudocysts is rare, with Gupta et al reporting only approximately 50 cases in the literature.11 Patients with this complication do not present with typical abdominal symptoms associated with chronic pancreatitis. Instead, cough, dyspnoea and chest pain are the initial symptoms. This is due to the invasion of the pancreatic pseudocyst into the thoracic cavity via the oesophageal hiatus or a congenital foramen like the foramen of Morgagni.
This leads to an inflammatory thoracic process very much like pancreatitis. However, when present in the thoracic cavity, it leads to localised inflammation and, at times, invasion of nearby structures. Haemoptysis is an uncommon presenting symptom of pancreatic mediastinal pseudocysts, which can result from the formation of pancreatic-pulmonary fistulas and cause erosion and liquefaction of the lung parenchyma, oesophagus and/or vasculature.10 11 We found mention of haemoptysis as a presenting symptom of this uncommon condition in only three other reports.9 10 12
In our patient, the findings of significant haemoptysis, characteristic infiltrates on CT chest, anaemia and progressively bloody BAL fluid led to the initial diagnostic consideration of diffuse alveolar haemorrhage. As the clinical picture and follow-up imaging evolved, it became apparent that his pulmonary haemorrhage, pneumothorax and pneumomediastinum were related to his pancreatic-pleural-pulmonary fistula. Complicating this case was the presence of secondary infection of the pseudocyst fluid.
Diagnosis of mediastinal pancreatic pseudocyst generally requires a contrast-enhanced CT and/or MR cholangiopancreatography to visualise pancreatic fluid collection tracking into the thorax.3 Sampling of the thoracic and abdominal fluid collections should reveal elevated amylase.12 Fluid analysis is also important as infection of the fluid is common, as was the case in our patient who had evidence of both bacterial and fungal superinfection. Fungal infections have been noted in nearly half of patients with pancreatic pseudocyst or necrosis and are associated with increased mortality.13 There was no evidence of fistulous connection with the gut on initial or follow-up imaging.
Management of mediastinal pseudocyst includes either percutaneous or endoscopic drainage.3 4 Patients often require parenteral nutrition. In some cases, octreotide has been used to reduce pancreatic secretions.14 One case report describes closure of fistulous tract by glue embolisation achieved by CT-guided injection of histoacryl glue into the tract.9 Surgical options are considered if ERCP and external drainage are unsuccessful, and include partial pancreatectomy or internal pancreatic drainage via pancreaticojejunostomy.5 Our patient required both ERCP with stenting of the PD and external drainage.
Learning points
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Haemoptysis can be the initial presentation in patients with pancreatic-pulmonary fistula, a rare complication of chronic pancreatitis.
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Contrast-enhanced CT imaging or MR cholangiopancreatography can aid in this diagnosis.
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Comparison of fluid characteristics from abdominal and pleural fluid collections can further provide confirmation. Fluid amylase levels are elevated.
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Effective treatment requires adequate fluid drainage and tailored antimicrobial therapy.
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Recovery can be prolonged and fungal infection is associated with worse outcomes.
Ethics statements
Footnotes
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Contributors HCL and LCI contributed equally to care of the patient and preparation of this manuscript. SK was attending physician for the patient and edited this manuscript.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.
References
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