Contrast-enhanced harmonic endoscopic ultrasound in the diagnosis of primary pancreatic B-cell non-Hodgkin's lymphoma.

Abstract

A 71-year-old male with a history of non-Hodgkin's lymphoma 26 years ago and considered in remission was presented with abdominal pain and bloating of 4 months duration, jaundice and weight loss of 15 pounds in the last 2 months. His total serum bilirubin was 24 mg/dL (direct bilirubin: 21 mg/dL), associated to elevated transaminases 3 times over the upper limit of normal value. Other laboratory data were normal. Contrast-enhanced computerized tomography scan showed a mass in the head of the pancreas with gastric and duodenal infiltration, abdominal lymphadenopathy, bile and pancreatic duct dilated and ascites. Endoscopic ultrasonography (EUS) showed a 60 mm hypoechoic mass in the head of the pancreas with common bile duct and portal vein infiltration. EUS also found lymphadenopathy, ascites, with dilation of the main pancreatic duct and common biliary duct. Initially, EUS-fine needle aspiration (EUS-FNA) was not conclusive in spite that quantitative and qualitative elastography were suspected for malignancy (mean strain ratio: 37). We performed a new EUS using contrast-enhanced harmonic EUS (CH-EUS, pentax-hitachi) with sonovue (2.4 mL) that showed a hypoenhanced pattern of the pancreatic mass. EUS-FNA with a 19-gage needle (expect needle, boston scientific) obtained sample of the pancreatic mass for histology and a diffuse large B-cell immunophenotype non-Hodgkin's lymphoma was diagnosed [Figures 1–3]. Figure 1 Endoscopic ultrasonography elastography showing the heterogeneous mass in the head of the pancreas (Strain Ratio: 30) Figure 2 Contrast-enhanced harmonic-endoscopic ultrasonography with a linear array ultrasound endoscope shows a hypoenhanced mass after contrast sonovue (Bracco) injection Figure 3 Histology showing a diffuse large B-cell immunophenotype non-Hodgkin's lymphoma Primary pancreatic lymphoma (PPL) is a rare tumor of the pancreas. Although it is a rare malignant tumor, the correct diagnosis is essential since their therapeutic management differs from other pancreatic tumors. In a retrospective study, it was encountered in 0.5% of patients with solid pancreatic masses, usually located in the head and appeared as a heterogeneous mass.[1] Endoscopic ultrasonography is the best modality for pancreatic lesion evaluation, although differentiating malignant lesions (adenocarcinoma, neuroendocrine tumor, primary lymphoma, metastases) remains a challenge. EUS-FNA is currently the preferred technique for the diagnosis of neoplasms of the pancreas.[2] Recently, CH-EUS has been reported as an adjunct in the diagnosis of pancreatic neoplasms.[3] However, the usefulness of CH-EUS in the PPL has been poorly studied because of the rarity of this entity. In a recent study, a case with metastatic pancreatic lymphoma CH-EUS appeared hyperenhancing.[4] We present a case of PPL in which CH-EUS showed as an hypoenhancing pattern.