Pseudoprogression of lung large cell neuroendocrine carcinoma resembling pancreatic cancer during durvalumab therapy.

A 74-year-old Asian man was referred for numb and painful sensation in the right upper limb. He was diagnosed with lung large cell neuroendocrine carcinoma and started receiving durvalumab therapy as second-line treatment. Sixteen days after the first dose, laboratory examination revealed increased liver enzyme levels and a marked inflammatory response. Contrast-enhanced computed tomography revealed an unenhanced tumor measuring approximately 25 mm in the head of pancreas and dilation of the intra- and extra-hepatic bile ducts. Magnetic resonance cholangiopancreatography confirmed stricture in the lower common bile duct and main pancreatic duct. We suspected acute cholangitis caused by a pancreatic cancer and performed an endoscopic biliary drainage. Two weeks after the procedure, computed tomography revealed significant shrinkage of the tumor. The tumor gradually reduced and pseudoprogression in lung large cell neuroendocrine carcinoma was ultimately diagnosed. Acute cholangitis caused by pseudoprogression resembling pancreatic cancer during immune therapy has not yet been reported. We are mindful that pseudoprogression should be considered as a differential diagnosis if a rapidly developing pancreatic tumor is observed during immunotherapy.

Primary hepatic lymphoma diagnosed using endoscopic ultrasound-guided liver biopsy: a case report.

BACKGROUND: Because of the rarity of primary hepatic lymphomas, diagnosis of this disease entity may often be difficult, and performing a liver biopsy is the only way to establish a definitive diagnosis. Recently, endoscopic ultrasound-guided liver biopsy has emerged as a safe technique for obtaining liver tissue. However, there is no report on the use of endoscopic ultrasound-guided liver biopsy for diagnosing primary hepatic lymphomas. CASE PRESENTATION: An 85-year-old Asian man was admitted to our hospital because of multiple liver lesions without any identifiable primary tumor or extrahepatic lymphadenopathy. Serum tumor markers, including alpha-fetoprotein, were in the normal range. We provisionally diagnosed the patient with a cancer of unknown primary origin with liver metastases. An endoscopic ultrasound-guided fine needle liver biopsy of the tumor in the left lobe of the liver was performed using a transgastric approach, and histology revealed a primary hepatic lymphoma of a diffuse large B-cell lymphoma type. CONCLUSIONS: Primary hepatic lymphomas are quite rare, and diagnosis is often difficult without performing a biopsy. Endoscopic ultrasound-guided liver biopsy is a useful diagnostic modality even in such cases.