ABSTRACT Introduction Enfortumab vedotin (EV), a Nectin‐4–targeted antibody–drug conjugate, is active in previously treated urothelial carcinoma. Cavitation of pulmonary metastases is classically linked to squamous histology or anti‐angiogenic/cytotoxic regimens; rarely reported under EV. Case Presentation A 69‐year‐old woman with upper‐tract urothelial carcinoma developed pulmonary and hepatic metastases. During EV, multiple lung nodules rapidly cavitated into thin‐walled lesions while liver disease shrank. No infectious symptoms; overall survival was 12 months from EV start. Discussion Cavitation likely reflects treatment‐related necrosis once infection and EV‐related pneumonitis are excluded. Diameter‐based criteria can misjudge response when solid nodules cavitate; short‐interval re‐imaging is advisable. Pulmonary response may not ensure systemic control. Conclusion Recognizing EV‐associated cavitation as a response pattern may prevent premature discontinuation of effective therapy and unnecessary antibiotics.

ABSTRACT Introduction SpaceOAR is a hydrogel spacer widely used to protect the rectum from radiation toxicity during prostate cancer treatment. Reported here is a case in which an abscess that developed following SpaceOAR placement was successfully treated with laparoscopic fenestration. Case Presentation A 70‐year‐old man with localized prostate cancer undergoing a radiation therapy course developed an abscess at the SpaceOAR placement site 76 days after implantation. Antibiotic therapy and percutaneous drainage were ineffective; thus laparoscopic abscess fenestration was performed. Abscess size reduction was noted, leading to clinical improvement and a favorable course. Conclusion This is the first known reported case of laparoscopic abscess fenestration for a SpaceOAR‐related abscess and the findings highlight the need to include abscess formation as a differential diagnosis even after more than 2 months following placement. Furthermore, this case indicates laparoscopic fenestration as a viable treatment option for a rectal spacer‐related abscess unresponsive to antibiotics or percutaneous drainage.

ABSTRACT Introduction Pheochromocytoma is a catecholamine‐producing tumor arising from the adrenal medulla. When it coexists with a tumor of different origin within the same adrenal gland, it is classified as a collision tumor involving a pheochromocytoma. Case Presentation The left adrenal tumor was identified in an 84‐year‐old Japanese woman and initially considered pheochromocytoma; however, rapid growth, lymphadenopathy, reduced 123 I‐MIBG uptake, and intense FDG (Fluorodeoxyglucose) accumulation raised suspicion of another tumor component. The patient received cyclophosphamide, vincristine and dacarbazine (CVD) chemotherapy followed by surgical resection. Histopathology revealed extensive necrosis in the diffuse large B‐cell lymphoma (DLBCL) component, suggesting a response to chemotherapy. Conclusion To the best of our knowledge, this is the fourth reported case of an adrenal collision tumor with pheochromocytoma and DLBCL, and the first treated with CVD followed by surgery. Collision tumors should be considered a differential diagnosis when adrenal masses present with atypical clinical or imaging features.

ABSTRACT Introduction Cerebral air embolism accompanied by right‐to‐left shunt through the venous system during Robot‐assisted partial nephrectomy (RAPN) is regarded as a rare occurrence, with a high mortality rate. Case Presentation A case of a 77‐year‐old man with renal cell carcinoma who developed cerebral air embolism during right retroperitoneal RAPN using AirSeal. Intraoperatively, a sudden drop in end‐tidal CO 2 was observed during tumor resection. Postoperatively, the patient developed seizures, and imaging revealed cerebral air embolization. Despite hyperbaric oxygen therapy and intensive care, he progressed to fatal cerebral infarction. Conclusion This case highlights the risk of serious brain stroke during RAPN. The pathways of air entry into the cerebral circulation occasionally remain unclear and are difficult to fully exclude preoperatively. Renal vein clamping and adequate insufflation pressure are recommended when the tumor is entirely endophytic or close to the renal vein, especially when performing a right retroperitoneal approach.

ABSTRACTBackgroundSpermatocytic tumor is a rare type of testicular germ cell tumor, accounting for approximately 1% of all testicular neoplasms.Case PresentationA 51‐year‐old male presented to the hospital with a painless mass in the left testis. Ultrasonography revealed a heterogeneous intratesticular mass with cystic components. Testicular tumor markers were within normal ranges. The patient underwent a left orchiectomy. Pathologically, the tumor was characterized by the presence of medium to large neoplastic cells and small neoplastic cells without sarcomatoid or anaplastic features. Immunohistochemically, the tumor was positive for SALL4 and negative for CD30, AFP, OCT3/4, PLAP, D2‐40, and hCG. Based on these findings, we diagnosed spermatocytic tumor of testis.ConclusionWe present a case of spermatocytic tumor, which is a distinct entity among testicular germ cell tumors, with a generally favorable prognosis following orchiectomy. However, long‐term follow‐up is recommended due to the potential for late metastasis.

ABSTRACTIntroductionInflammatory myofibroblastic tumor (IMT) of the bladder is a rare benign tumor characterized by atypical spindle cell proliferation and inflammatory cell infiltration, typically involving lymphocytes and plasma cells.Case PresentationA 38‐year‐old woman presented with micturition pain and urinary frequency. Cystoscopy revealed an elevated tumor with edematous mucosa on the anterior bladder wall. Transurethral resection confirmed IMT of the bladder but was incomplete, prompting laparoscopic partial cystectomy with cystoscopy guidance. At 2‐year follow‐up, the patient remained asymptomatic with no recurrence.ConclusionComplete resection is the standard treatment for bladder IMT. When the tumor extends beyond the bladder wall, laparoscopic partial cystectomy with cystoscopy guidance offers a safe and effective surgical approach for achieving complete resection with adequate margins.

ABSTRACTIntroductionPartial splenic embolization is a valuable option to manage hypersplenism and reduce portal pressure while preserving splenic function. It may improve surgical safety in patients with portal hypertension.Case PresentationA 67‐year‐old Japanese male with renal cell carcinoma and hepatitis B‐related liver cirrhosis presented with thrombocytopenia, collateral vessels, and a splenorenal shunt. Due to concerns regarding surgical risk, partial splenic embolization was performed preoperatively. Following the procedure, the platelet count increased, and collateral circulation decreased. These improvements enabled a safe left radical nephrectomy.ConclusionPartial splenic embolization can be an effective preoperative strategy in patients with renal tumors and coexisting portal hypertension. By improving hematologic parameters and reducing vascular risk, it may facilitate curative surgery in high‐risk patients and expand treatment options.

ABSTRACTIntroductionCombined rectal impalement (RI) and bladder perforation (BP) is an extremely rare injury pattern, with limited case reports and no established consensus on their diagnosis and management.Case PresentationA 50‐year‐old man sustained a perianal impalement injury caused by a metal rod at a construction site. He presented with perianal pain and gross hematuria (GH). Imaging revealed RI and extraperitoneal BP. A colostomy was performed on the same day as the injury, and transurethral coagulation of the bladder (TUC) was performed on the 6th day, during which a bladder mucosal defect was identified. Postoperatively, the GH reduced, and no persistent voiding or defecation dysfunction was observed.ConclusionIn patients with RI and GH, concomitant BP should be suspected. Although colostomy is almost always required for rectal injury, extraperitoneal BP can be cured with transurethral intervention and catheterization.