An unusual neck swelling: Extension of mediastinal pseudocyst into the neck.

A 35-year-old male presented with a history of painless swelling on the right side of the neck of 2 weeks duration. The patient also had progressively increasing painless dysphagia and dry cough with no dyspnea. He had history of significant alcohol consumption. Clinical examination revealed a cystic swelling in the right lateral part of the neck [Figure 1]. Contrast enhanced computed tomography (CECT) of the chest and abdomen revealed a hypodense collection measuring 2.5 cm size in the neck [Figure 2] that was communicating with a large collection measuring 8 cm in the mediastinum around the trachea [Figure 3]. Also noted was the presence of left-sided pleural effusion and calcification in the uncinate and head of the pancreas [Figure 4]. The main pancreatic duct was not dilated. The serum amylase level was elevated (460 IU/L). Endoscopic ultrasound (EUS) revealed changes of chronic calcific pancreatitis with an anechoic periesophageal collection suggestive of mediastinal pseudocyst [Figure 5]. The patient was started on pancreatic enzyme supplementation and subcutaneous octreotide. The patient had gradual improvement and his neck swelling subsided in 2 weeks, and the dysphagia was alleviated. The patient was discharged and was found to be asymptomatic after 3 months of follow-up.

Figure 1

Cystic swelling in the right lateral part of the neck (arrows)

Figure 2

CT neck: Hypodense collection in the neck (arrows)

Figure 3

CT chest: Large collection in the mediastinum compressing the trachea. Left pleural effusion can also be seen

Figure 4

CT abdomen: Calcification in the uncinate and head of the pancreas

Figure 5

EUS: Mediastinal pseudocyst (arrows)

Pancreatic pseudocysts are usually peripancreatic in locations but can also be found at various atypical locations such as spleen, mediastinum, kidney and pelvis.[1] Mediastinal pseudocysts are very rare. These pseudocysts reach the mediastinum as a result of posterior duct disruption with tracking of the fluid across one of the openings naturally present in the diaphragm. These pseudocysts either rupture into the pleural space or very rarely extend in to the neck.[23] The differential diagnosis for cystic lesions in neck include a wide variety of inflammatory and neoplastic diseases as well as acquired and congenital diseases including thyroglossal cysts, lymphangiomas, dermoid cysts, cystic lymph nodes, neurogenic tumors, vascular malformations, abscesses, cystic lesions of thyroid and salivary glands.[4] The clinical and imaging features such as locations, composition, and vascularity, and if required fine needle aspiration cytology may help in correct diagnosis. They can be managed with conservative medical treatment or endoscopic or surgical intervention.[3] The management approach depends on the pancreatic ductal anatomy, size of the pseudocyst, and available expertise.[3] Small pseudocysts with normal pancreatic duct anatomy in absence of major duct disruptions can be managed with conservative medical treatment including medical management with octreotide.

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