The incidence of cerebral infarction in patients with non-valvular atrial fibrillation is 5% per year on average, and since there are currently estimated to be more than 800,000 patients with atrial fibrillation in Japan, the use of oral anticoagulants is an important clinical issue. For many years, the only oral anticoagulant used in Japan was warfarin, but the use of direct oral anticoagulants (DOACs) has increased rapidly since they became available due to their superior efficacy in preventing thrombosis. The number of patients using these drugs has also increased, but this has been accompanied by an increase in bleeding-related adverse events and cerebral infarction. On the other hand, two types of neutralizers are now available to prevent hemorrhages in patients receiving DOACs in the preoperative period or in emergencies. In this article, we discuss the predicted anticoagulant effect of one DOAC, apixaban, and the characteristics of DOAC neutralizers.

We report a case of follicular lymphoma located in the retroperitoneal area behind the distal pancreas, which was successfully resected by a laparoscopic approach along the ligament of Treitz. A 70-year-old man attending our hospital for chronic obstructive pulmonary disease was incidentally found to have a 23-mm retroperitoneal tumor. The tumor was located behind the distal pancreas near the superior mesenteric artery and left renal vein. Laparoscopic retroperitoneal tumor resection was performed because the tumor was suspected to be malignant owing to the tumor growth over time detected by computed tomography and positron emission tomography 18F-FDG uptake. The postoperative course was uneventful, and the pathological findings indicated that the tumor was follicular lymphoma.

Case 1 was a 58-year-old man presenting with a dome-shaped elastic-soft nodule measuring 24 × 18 mm on the left buttock, which had developed five years previously. Case 2 was a 63-year-old woman with an elastic-soft subcutaneous nodule (18 × 22 mm) on the posterior side of the right thigh, which she had first noticed five years before. Case 3 was a 79-year-old man with an elastic-soft subcutaneous nodule (17 × 10 mm) on the lateral side of his left thigh, which he had become aware of four years previously. In all three cases, adipose tissue proliferation was observed between the dermal collagen fibers. Nevus lipomatosus cutaneous superficialis (NLCS) was diagnosed, with lipoma or soft fibroma considered in the differential diagnosis. All three nodules were excised. In case 3, the signal was not suppressed on magnetic resonance imaging (MRI) with fat-suppressed T1-weighted images. Since the excisional design for cases of NLCS is different from that of lipoma, MRI was considered useful in the preoperative diagnosis.