Abdominal lymphocele misdiagnosed as pancreatic cystic lesion, report of two cases. EUS features, accuracy, safety and role of preoperative FNA

We present two cases of diagnosis of abdominal lymphocele by means of EUS features and FNA results, previously misdiagnosed as pancreatic cystic lesions at the imaging studies. The first case is a 58 year-old female that has been studied for a mild abdominal pain and a uterine mioma. An abdominal ultrasound showed a peripancreatic hypoecoic lesion compatible with pathologic lymph node. Then an MDCT was performed, concluding that the lymph node was actually a cystic lesion emerging from the pancreas, not ruling out a pancreatic cystic neoplasia. The linear EUS showed an anechoich lesion clearly extrinsec from the pancreatic body, whit fine septa and no solid component. A single pass FNA was performed with a 22G needle across a very elastic capsule, obtaning 2ml of white fluid. CEA and CA 19.9 levels were normal, meanwhile a very high trygliceride (3663mg/dL) and amylase (240 U/L) levels were detected. The cytology specimen didn? t showed malignancy.

The second case is a 68 year-old female with a moderate abdominal pain and a family history of pancreatic cancer and a HCV infection. The lab tests were anodyne. An abdominal MDCT revealed a 91×83×45mm septated, hypodense lesion growing from the pancreatic parenchyma, with the presumptive diagnosis of pseudocyst. The linear EUS then showed an 89×64mm cystic lesion whit no relationship whit the pancreatic parenchyma. Then an FNA was performed with a 22G needle under prophylaxis, observing an elastic capsule. 8ml of a plain milky white fluid were obtained. A cell count of the fluid determined 240 leucocytes per mm³, with a 100% of them corresponding to lymphocytes. High levels of trygliceride (1936mg/dL) were detected, but the amylase, CEA, and CEA 19.9 levels were normal. The cytologic examination showed abundant lymphocytes. Because of recurrent pain, the patient underwent surgical resection of the lesion. Pathology examination of the surgical specimen described frequent foamy hystiocites inside a fibrotic septa and some nests of lymphocytes. A preliminar diagnosis of pseudocyst was done.

Abdominal lymphoceles are a rare condition, usually undistinguible from other cystic lesions including neoplasias and with an increasing incidence because of the high rate of imaging studies being peformed nowadays. There is only one report of this kind of lesions primarily diagnosed by means of EUS in one patient. Here we present two cases of abdominal lymphocele correctly diagnosed after EUS FNA. The accuracy was shown to be higher than a multidetector CT or transabdominal ultrasound, and maybe even more reliable than the pathology exam of the surgical specimen itself. A very high level of tryglicerides with or without high amylase, a milky-white appearence of the fluid, internal septa and probably a very elastic, even springy" sign of the capsule during FNA are combined features very suggestive of this condition. No complications of the procedure were observed