Journal of The Association of Physicians of India ■ Vol. 64 ■ March 201680

Mediastinal Pseudocyst in Acute on Chronic PancreatitisSushil Kumar Mishra1, Pawan Kumar Jain2, Sukhdev Gupta3

AbstractPseudocyst is a common complication of Acute and chronic pancreatitis. However, its extension into the mediastinum is a rare entity. We present a case of 52 years male with acute on chronic pancreatitis (alcohol related) who presented with dysphagia and dyspnoea and was found to have a pancreatic pseudocyst extending upto the neck. Ultrasound fails to pick up mediastinal pseudocysts and requires additional imaging modalities - CT and MRI. Management of Mediastinal pseudocyst depends upon underlying etiology, ductal anatomy, size of the pseudocyst, and availability of expertise. Small pseudocysts in asymptomatic patients may resolve spontaneously, but requires prolonged conservative therapy with somatostatin or its analogue and Total Parenteral Nutrition. Ruptured pseudocyst in a symptomatic unstable patient requires surgical resection. Endoscopic ultrasound guided drainage (transmural or transpapillary) and Main Pancreatic Duct stenting are safe and effective treatment modality.

1Gastroenterologist, 2HOD Radiology, 3Senior Resident Gastroenterology, Hindu Rao Hospital, New DelhiReceived: 24.05.2013; Revised: 06.02.2015; Accepted: 11.02.2015

Introduction

Chronic pancrea t i t i s (CP) i s a progressive, inflammatory disease

of the pancreas , l eading to s low destruction of pancreatic parenchyma and progressive fibrosis.1 It presents clinically as upper abdominal pain wi th or wi thout exocr ine and/or endocrine insufficiency occurring late in the course of the disease (>90% loss of pancreatic function) resulting in steatorrhea and diabetes mellitus.

The prevalence of CP in India is 115-200/100,000 population as compared to 10-15/100,000 in the West.2 The common complications of CP are pseudocysts (15.8%), biliary obstruction (8.2%) and Pancreatic cancer (4.1%).3

We present a case of acute on chronic pancreatitis with pseudocyst extending upto the neck.

Case Report

A 52 years gentleman, consuming alcohol about 100 grams/day for the last 28 years; was admitted with pain in upper abdomen for last 2 months which was continuous and radiating to the back, severe in intensity requiring injectable analgesics and worsened over the last one week. It was associated with dysphagia for both solids and liquid and dyspnea. He also noticed a firm swelling on the right side of neck (Figure 1) and painless swelling of the right hand (Figure 2). General examination revealed fullness of right side of neck along with swelling of right upper limb. On systemic examination, he was found to have ascites without

any organomegaly and bilateral pleural effusion. Biochemical investigations revealed Hb-12.4 G%, TLC-14400, PLT-340 x 103, LFT/KFT-normal and S. Amylase -1090 u/L. He underwent a CECT abdomen and chest (Figure 3) which revealed calcification in head of pancreas with grossly dilated MPD, a 5.6 x 3.6 cms heterogeneously enhancing peripancreatic collection extending upto the neck and compressing the heart, esophagus, stomach and trachea. The ascitic fluid examination revealed a protein of 2.3 G% and amylase of 17380 U/l but no cells. His endoscopy revealed extrinsic compression of esophagus with no varices (Figure 4). A 2D ECHO revealed mild AR and trace TR but no pericardial effusion and a LVEF of 75%. He was put on Octreotide, IV fluids, Inj. Cefotaxime and was kept NPO but condition did not improve and he was referred to other center for pancreatic stenting and EUS guided drainage of fluid collection as these facilities were not available in our hospital.

Discussion

Diagnos is o f acute on chronic pancreati t is was made on cl inical and morphological criteria. Clinical presentation of severe pain in abdomen, raised amylase and CT finding of calcification of pancreas and dilated

Fig. 1: Swelling on the right neck

Fig. 2: Swelling of the right hand Fig. 3: CECT neck

Journal of The Association of Physicians of India ■ Vol. 64 ■ March 2016 81

MPD and pancrea t i c pseudocy s t extending upto the neck; without exocrine and endocrine insufficiency.

P a n c r e a t i c p s e u d o c y s t i s a well known complication of acute pancreatitis (10%) and more commonly seen in chronic pancreat i t i s (30-40%).4 Pseudocyst of the pancreas is a localized fluid collection that is rich in amylase and is surrounded by a wall of fibrous tissue (not epithelium). Pancreatic pseudocysts are seen in the peripancreatic region but can rarely be seen in atypical locations - liver, spleen, kidney, mediastinum and pelvis causing chal lenges in diagnosis and management. Two-third of pseudocysts are connected with the pancreatic duct system, either directly (ductal disruption due to increased pancreatic ductal pressure- stenosis, calculi or protein plugs obstructing the main pancreatic ductal system) or indirectly due to the pancreatic necrosis following an attack of acute pancreatitis.5 The acute complications of pseudocysts are rupture (into Gl tract/peritoneum/vascular ), infection or haemorrhage (catastrophic course due to erosion of a major vessel in the vicinity of the pseudocyst). The chronic complications of pseudocyst are gastric outlet obstruction, Biliary obstruction and portal hypertension (due to compression of splenic/portal vein). Very rarely the ductal disruption occurs in retroperitoneum which then tracks into the mediastinum through the esophageal, aortic, foramen of Morgagni or direct ly through the diaphragm causing dysphagia and dyspnea as was seen in our patient.

Mediastinal pseudocyst has been reported as small case series.4 Bhasin’s

series from Chandigarh reported 12 patients of mediastinal pseudocyst in a decade wherein M:F ratio was 10:2, mean age 36.1 (range 21-52) years, CP was seen in 9 cases and AP in 3 cases. Alcohol as etiology was seen in 67% cases, biliary and idiopathic CP in 16% each. Abdominal pain was the most common symptom; dyspnea in 42% and dysphagia in 17% (2 cases had both with large pseudocysts- 6 and 8 cms). USG could not pick up the collection and all patients required CT or MRI for diagnosis.

Ideal management for mediastinal p s e u d o c y s t w o u l d d e p e n d u p o n aetiology, ductal anatomy, size of pseudocyst and expertise available at the centre. Medical treatment would result in spontaneous recovery for small pseudocysts with NPO, octreotide i n j e c t i o n s b u t c a u s e s p r o l o n g e d morbidity.4 Surgical decompression procedures are varied and include pancreatic resection and/or external or internal drainage which are invasive procedures requiring laparoscopic and thoracoscope procedure.5 Endoscopic ultrasound is increasingly being used to guide transmural internal drainage of mediastinal pseudocyst. It helps to identify wall thickness, the site to be punctured in a nonbulging pseudocyst as well as help avoid major vessels puncture.6 Endoscopic drainage of 11 out of 12 patients in Bhasin’s series resolved in 6 weeks with transpapillary drainage. All pat ients had ductal disruption and needed pancreatic stenting.

Our patient is unique in many ways. Although he had acute on chronic

pancreatitis (alcohol related), he did not have exocrine/endocrine insufficiency, which anyway comes late in the disease. He presented in the first week with acute abdominal pain, dysphagia and dyspnea. CECT revealed pancreatic pseudocyst extending upto the neck and compressing the subclavian vein, esophagus and the trachea. Trial of conservative treatment did not work and the patient refused endoscopic treatment and left against medical advice.

I n c o n c l u s i o n , m e d i a s t i n a l pseudocyst should be suspected in a patient of pancreatitis with sudden onset of dysphagia and dyspnea and is a rare but life-threatening complication. A high index of suspicion is required by the physician as USG fails to pick up the lesion and needs CT/MRI. Medical management for small pseudocyst requires NPO, Inj. octeotide but rarely undergoes spontaneous resolution and would require EUS drainage and/or MPD stenting and has largely replaced surgical intervention.

References1. Tandon RK, Sato N, Garg PK. Chronic pancreatitis: Asia-Pacific

consensus report. J Gastroenterol Hepatol 2002; 17:508-18.

2. Garg PK. Chronic Pancreatitis in India and Asia. Curr Gastroenterol Rep 2012; 14:118-124.

3. Johnson RH Jr, Owensby LC, Vargas GM, et al. Pancreatic pseudocyst of the mediastinum. Ann Thorac Surg 1986; 41:210-2.

4. Bhasin et al Clinical presentation, radiological features, and endoscopic management of mediastinal pseudocysts: experience of a decade. Gastrointestinal Endoscopy 2012; 76:5.

5. Bonnard A, Lagausie P, Malbezin S, et al. Mediastinal pancreatic pseudocyst in a child. A thoracoscopic approach. Surg Endosc 2001; 15:760.

6. Gupta R, Munoz JC, Garg P, Masiri G, Mahmon MS, and Lambiase RL, Mediastinal pancreatic pseudocyst - A Case report and review of the literature. Med Gen Med 2007; 9:8.

Fig. 4: Endoscopy: Extrinsic compression of esophagus

Fig. 5: CECT : Thorax

Fig. 6: CECT Abdomen