An anastomosing hemangioma mimicking a renal cell carcinoma in a kidney transplant recipient: a case report

Background Although anastomosing hemangiomas are very rare and benign vascular neoplasms, these tumors are more common among patients with end-stage kidney disease. Incidental finding of these tumors in the kidney or adrenal gland has been reported. Herein, we describe a case in which an anastomosing hemangioma was misdiagnosed as a renal cell carcinoma before kidney transplant. Case presentation A 35-year-old woman with lupus nephritis was admitted to our emergency department for suspected uremic symptoms of nausea and general weakness. She had received hemodialysis due to end-stage kidney disease, and a living-donor kidney transplantation from her father was planned. On pre-operative contrast-enhanced computed tomography and magnetic resonance imaging, a 1.7 cm renal cell carcinoma was observed in the right kidney. On staining after radical nephrectomy, irregularly shaped vascular spaces of various sizes were observed, with these spaces having an anastomosing pattern. As the findings of the anastomosing hemangioma are similar to those of a renal cell carcinoma on imaging, histology examination was necessary to confirm the diagnosis of anastomosing hemangioma and to prevent delay in listing for kidney transplantation. Good kidney function was achieved after transplantation, with no tumor recurrence. Conclusion Our case underlines the importance for prompt surgical resection of an enhancing renal mass to confirm diagnosis in patients scheduled for kidney transplantation to avoid any delay.

Anastomosing Hemangioma of the Larynx: A Unicorn among Head and Neck Tumors

Objective: Anastomosing hemangioma (AH) is a novel tumor of vascular origin. Though well-documented in the kidney and retroperitoneum, only a single case has been documented in the head and neck, and AH in larynx has not been described. Methods: A 37-year-old male presented with difficulty in breathing, and hoarseness. Imaging revealed a lesion involving left paraglottic and cricothyroid spaces with destruction of cricoid cartilage, suggestive of a malignant cartilageneous neoplasm. Multiple biopsies were non-diagnostic. Results: Intraoperative frozen section during transcervical resection showed a vascular tumor devoid of nuclear atypia. Histopathological examination revealed a vasoformative tumor comprised of anastomosing capillary-sized vessels lined by flat and hobnail endothelial cells, consistent with AH. The patient was disease-free at 12 months. Conclusion: AH are rare neoplasms that may mimic a malignancy on imaging, especially in sites where they have not been documented. Due to their vascular nature, biopsies are often non-diagnostic, making preoperative diagnosis difficult. Frozen section may assist in decision-making on the extent of resection required.