[Incidence of Antiresorptive Agent-Related Osteonecrosis of the Jaw in Urologic Cancers].

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is a serious adverse event of bone resorption inhibitors (BRIs), such as zoledronic acid and denosumab. Based on the results of phase 3 clinical trials for BRIs, the frequency of ARONJ is 1 to 2%, but the actual frequency is presumed to be higher. We studied 143 patients with urologic cancers with bone metastases who were treated with zoledronic acid or denosumab at our hospital between April 2007 and March 2020. ARONJ occurred in 24 patients (16.8%) ; that is, 14 of the 113 patients (12.4%) who received zoledronic acid alone, 8 of the 24 patients (33.3%) who received denosumab alone, and 2 of the 6 patients (33.3%) who sequentially switched from zoledronic acid to denosumab. ARONJ was cured in 8 patients (33.3%), improved in 3 patients (12.5%), unchanged in 4 patients (16.7%), and worsened in 9 patients (37.5%). The frequency of ARONJ increased as the duration of BRI administration prolonged. Time-to-ARONJ was shorter in patients treated with denosumab than in patients treated with zoledronic acid. The occurrence of ARONJ may be underestimated; therefore, further studies are needed to investigate the actual frequency of ARONJ in Japan.

[A Case of Rapidly Growing Sarcomatoid Urothelial Carcinoma of the Renal Pelvis and Ureter].

75 year-old man followed up regularly for the treatment of lung cancer came to our hospital with a chief complaint of general malaise. Blood test results showed deterioration in the renal function, and computed tomography (CT) confirmed left hydronephrosis. He was admitted to the hospital with the diagnosis of obstructive pyelonephritis. Despite antibiotic therapy after the left ureteral stent placement, CT on day 19 of hospitalization showed an enlarged soft tissue shadow along the renal pelvis and ureter, which was suspected to be peripelvic urinary extravasation caused by stent occlusion. We decided that conservative treatment would not improve his condition and conducted surgical therapy considering the possibility of malignancy. Intraoperatively, viscous and fragile tumor affected the renal pelvis and ureter. The operation resulted in left nephrectomy because radical resection was impossible. The pathological diagnosis was sarcomatoid urothelial carcinoma of the renal pelvis with ureter origin. He died due to multipleorgan failureon day 20 after theope ration. Were port a caseof sarcomatoid urothelial carcinoma in the upper urinary tract that was difficult to diagnose preoperatively based on imaging studies.

[A Case of Renal Epithelioid Angiomyolipoma with Recurrence in the Abdominal Cavity].

A 37-year-old man with no symptoms or family history of tuberous sclerosis complex presented to our hospital with abdominal pain in 2013. Abdominal computed tomography (CT) revealed a rupture in the right renal angiomyolipoma (AML) having a maximum diameter of 7 cm. He had undergone a transarterial embolization. Follow-up CT showed an increase in the size of the right tumor to 11 cm, and therefore, right nephrectomy was performed in 2016. The diagnosis of epithelioid AML (EAML) was confirmed. In 2019, he was diagnosed with a solitary tumor near right-sided transverse colon, which was resected and showed recurrence of EAML. He was disease-free 6 months after surgery. EAML has malignant potential, with 30-50% of reported EAML cases resulting in local recurrence or distant metastasis. Previous recurrence or metastasis may occur 0.25-12 years postoperatively. Furthermore, multiple and unresectable recurrences or metastases, arising early in the postoperative period may lead to a poor outcome. Therefore, close and long-term follow-up is required.