Objective: In the differential diagnosis between uterine fibroids and uterine sarcomas, realworld magnetic resonance imaging (MRI) diagnostic information is scarce; furthermore, high diagnostic sensitivity is important in clinical practice. We previously developed a diagnostic algorithm to detect uterine sarcoma with high sensitivity using simple MRI images and serum lactate dehydrogenase (LDH) levels. In this multicenter study, we investigated the preoperative diagnosis of sarcoma in the real world and further validated the usefulness of our diagnostic algorithm. Methods: Of 154 uterine sarcomas and 154 uterine fibroids treated at 15 centers between January 2006 and December 2020, 139 sarcomas (16 smooth muscle tumors of uncertain malignant potential) and 141 fibroids with diffusion-weighted imaging information were included in the analysis. The diagnostic algorithm was validated by 3 radiologists who were blinded to the clinical information and pathologic diagnoses and who read the MRIs. Results: The sensitivity/specificity of preoperative diagnosis was 77.7%/92.9% for the preoperative report; 92.1%/72.3% for algorithm A; and 82.0%/85.8% for algorithm B (McNemar’s test p<0.05). Comparison of overall survival rates among 3 groups (Group 1: negative A, Group 2: positive A and negative B; Group 3: positive B) using algorithms A and B showed p=0.012. On multivariate analysis, stage, and serum LDH level were independent prognostic factors. Conclusion MRI is useful for preoperative diagnosis of uterine sarcoma, and the sarcoma diagnostic algorithm presented in this study is an option for diagnosing sarcoma with greater sensitivity. This information should be shared with patients.

Popliteal artery entrapment syndrome (PAES) is a rare cause of intermittent claudication. Optimal strategies and management have been debated. We report two cases of PAES that were treated with respective different procedures. Case 1 : A 53-year-old male with intermittent claudication was referred to our department with PAES with a decrease in the ankle brachial index (ABI) with plantar flexion. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) showed medial deviation and compression of the popliteal artery by the medial head of the gastrocnemius muscle. The patient received excision of the medial head of the gastrocnemius muscle and thrombectomy of the popliteal artery. The diagnosis was confirmed as PAES type 2 during the procedure. Case 2 : A 37-year-old male presenting intermittent claudication and declining ABI in his left lower extremity was diagnosed with PAES by contrast CT. MRI and CT indicated that a fibrous band was compressing the popliteal artery. The findings of the imaging studies were confirmed during the subsequent surgical procedure and it was diagnosed as PAES type 4. In addition to removal of the band, popliteal artery interposition using a saphenous vein graft was performed due to severe stenosis with intimal hyperplasia. Pathological findings of the excised artery showed intimal hyperplasia and degeneration of elastic fibers in the media due to chronic compression. Although a large volume of retrospective data exists on PAES, recommendation of a particular operative procedure has not yet been derived. Thus, the treatment for PAES should be individually determined based on etiology and status of affected vessels.

A 54-year-old man with a sacral abdominal aortic aneurysm (4cm) complained of lower abdominal pain. An abdominal computed tomographic (CT) scan revealed a 1cm expansion in 2 weeks. The abdominal aorta was replaced with an in situ expanded polytetrafluoroethylene graft. Granulomatous lymphoadenitis was diagnosed in the aneurysm wall by histological examination. The patient's postoperative course was uneventful, and anti-tuberculosis medical drug therapy was given for 6 months.