A case report of a collision tumor composed of pancreatic ductal adenocarcinoma and peri-pancreatic mucosa-associated lymphoid tissue lymphoma.

BACKGROUND: Collision tumors are composed of two distinct tumor components. Collision tumors composed of pancreatic ductal adenocarcinoma and malignant lymphoma occurring in the pancreas have not been previously described in the scientific literature. In this case report, we describe a unique patient with a collision tumor composed of pancreatic ductal adenocarcinoma and peri-pancreatic mucosa-associated lymphoid tissue (MALT) lymphoma occurring in the pancreas. CASE PRESENTATION: An 82-year-old woman presented to our hospital complaining of dizziness. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a large lymphoid lesion spreading from the peri-pancreatic tissue heading to the hepatic hilar plate, involving the hepatoduodenal ligament and the entire duodenum, also showing a hard tumor in the pancreas head. We performed echo-guided needle biopsies for each tumor and diagnosed a collision tumor composed of pancreatic ductal adenocarcinoma and low-grade B cell lymphoma. The patient underwent pancreaticoduodenectomy. The resected specimen showed an elastic hard tumor, 90 × 75 mm in size, located in the pancreatic head, and a whitish-yellow hard tumor involving the lower bile duct, 31 mm in size, located in the center of the pancreatic head. Pathological and immunohistochemical examination proved that pancreatic ductal adenocarcinoma and MALT lymphoma originating from the peri-pancreatic head collided in the pancreatic head. CONCLUSIONS: To best of our knowledge, this is the first report of a surgically resected collision tumor of pancreatic ductal adenocarcinoma and MALT lymphoma originating from the peri-pancreatic head. A needle biopsy is useful when inconsistent findings are observed on diagnostic CT and MRI of tumor lesions since there is the possibility of a collision tumor.

Disappearance of Renal Cysts Included in Ice Ball During Cryoablation of Renal-Cell Carcinoma: A Potential Therapy for Symptomatic Renal Cysts?

PURPOSE: To retrospectively evaluate the effect of cryoablation of renal-cell carcinoma on nearby renal cysts with the goal to investigate the potential for an alternative therapy to treat symptomatic renal cysts. MATERIALS AND METHODS: The study population comprised 46 cysts (mean size, 12 mm; range, 5-43 mm) that were within or near the ice ball during cryoablation in 22 patients. Size change of each cyst was evaluated via enhanced CT or MR imaging before and 1, 3, 6, and 12 months after cryoablation. Forty-one cysts were also followed after 12 months. Variables including positional relationship between the cyst and the ice ball were evaluated via linear regression analysis using generalized estimating equation models to determine which factors affected cyst shrinkage rate at 12 months. RESULTS: Fifteen, 12, and 19 cysts were completely included in, partially included in, or excluded from the ice ball, respectively. The overall shrinkage rate was 62%, and 57% of cysts (26 of 46) had disappeared at 12 months. Only the relationship between the cyst and the ice ball was significantly (P < .001) associated with cyst shrinkage rate. Cyst disappearance rates at 12 months were 100% (15 of 15), 67% (8 of 12), and 16% (3 of 19) for cysts completely included, partially included, and excluded from the ice ball, respectively. Among the 22 cysts that disappeared at 12 months and continued to be followed, none recurred after 12 months. CONCLUSIONS: All renal cysts that were completely included in the ice ball disappeared after cryoablation, demonstrating the potential utility of cryoablation as an alternative therapy for symptomatic renal cysts.

Recurrent rupture of intercostal artery aneurysms in neurofibromatosis type 1.

Vasculopathy associated with neurofibromatosis type 1 (NF-1) can cause a spontaneous hemothorax, which is an uncommon but life-threatening complication of the disease. We report a case of recurrent rupture of intercostal artery aneurysms in an NF-1 patient. A 40-year-old man with NF-1 suffered from a right spontaneous hemothorax. The bleeding source was not identified by dynamic contrast-enhanced computed tomography (CT), so he was initially treated by conservative therapy. However, repeated contrast CT revealed aneurysms of the right 10th intercostal artery. They were successfully occluded by transcatheter arterial embolization (TAE). Seven months afterward, he presented with sudden lower back pain and was diagnosed with a contralateral spontaneous hemothorax due to a ruptured aneurysm of the left 12th intercostal artery. TAE was successfully performed.