Imaging findings of retroperitoneal anastomosing hemangioma: a case report and literature review

Systematic Review and Case Report of a Left Gonadal Vein Anastomosing Hemangioma

Background/Objectives: Anastomosing hemangioma (AH) is a rare, benign vascular tumor predominantly found in the genitourinary tract and often associated with impaired renal function. Due to its nonspecific radiological features, AH is frequently misinterpreted as a malignant vascular neoplasm, particularly angiosarcoma (AS), leading to potentially unnecessary surgical interventions. This study presents a systematic review of AH cases and describes a rare instance of retroperitoneal AH arising from the left gonadal vein, which was resected due to diagnostic uncertainty. Methods: A 68-year-old man underwent imaging for benign prostatic hyperplasia, incidentally revealing a 15-mm hypervascular retroperitoneal nodule adjacent to the left psoas muscle. Imaging findings, including moderate metabolic uptake on 18FDG-PET/CT, raised suspicion for AS. Given the diagnostic uncertainty and high-risk location, the multidisciplinary team (MDT) recommended surgical resection. Laparoscopic excision was performed, and histopathological analysis confirmed AH. The patient remained asymptomatic at a 22 month follow-up. In addition, a systematic review of 159 cases from 64 studies (2009-2024) was conducted to analyze radiological features, treatment approaches, and outcomes. Results: Among the reviewed cases, 68% were incidentally diagnosed, with AH occurring predominantly in the genitourinary system (70%), especially in the kidney, adrenal gland, and ovary. Chronic kidney disease (CKD) was present in 23.3% of cases, while 19.5% had a history of malignancy. Imaging was inconclusive in differentiating AH from malignancies: CT (71.9%) and MRI (6.1%) were the most used modalities, but none could reliably exclude AS. Management strategies included upfront surgical resection in 85%, while a growing proportion (9%) of cases underwent biopsy-based observation rather than immediate surgery. No cases were followed with imaging alone. Conclusions: AH remains a diagnostic challenge due to its overlap with malignant vascular tumors. While surgical excision is often performed, our review highlights an increasing trend toward conservative management with biopsy-based diagnosis. Improved awareness and the integration of histopathology, molecular markers, and MDT-based decision-making are crucial to prevent overtreatment in cases of suspected AH.

Clinical characteristics of renal anastomotic hemangioma

In this editorial, we comment on the article by Chen and Cai. We focus on renal anastomotic hemangioma, which is a rare benign hemangiomatous disease. This disease has unique clinical characteristics. Its biological behavior is benign, but its imaging results are similar to those of renal cancer. Renal anastomotic hemangioma is easy to misdiagnose and can lead to unnecessary radical nephrectomy. Therefore, urologists need a better understanding of this disease. We believe that patients with renal anastomotic hemangioma should receive individualized diagnosis and treatment to avoid overtreatment.

Retroperitoneal infantile hemangioma: a case report and literature review

BACKGROUND

Retroperitoneal infantile hemangioma (RIH), a type of primary retroperitoneal tumors, are exceptionally rare in clinical practice. Infantile hemangiomas typically manifest on the skin's surface. RIHs are exceptionally rare and typically small. In adults, these tumors often manifest without specific clinical symptoms or detectable signs for a definitive diagnosis. This case report details a patient diagnosed with RIH. We recommend complete excision of the tumor after a comprehensive evaluation, followed by postoperative pathology, to achieve a conclusive diagnosis. We believe that managing critical retroperitoneal structures and vessels intraoperatively presents a significant challenge for all procedures involving primary retroperitoneal tumors. A 47-year-old male was diagnosed with gallstones and underwent surgery 3 months ago at other institution for unexplained nausea and vomiting. Follow-up imaging 2 months after surgery revealed a retroperitoneal mass below the left renal pole. Upon presentation to our hospital, the patient continued to experience intermittent nausea and vomiting, with no other significant symptoms or signs. Considering the patient's 8-year history of hypertension, a paraganglioma was initially suspected. We performed the laparoscopic mass resection after a detailed assessment. However, postoperative pathology revealed it a capillary hemangioma (old term)/infantile hemangioma.

CONCLUSION

RIHs are exceedingly rare benign tumor. The possibility of malignancy should be ruled out, and surgical resection is recommended following a thorough evaluation, with the diagnosis confirmed through pathological examination.

Primary anastomosing hemangioma as a preoperative diagnostic mimicker of retroperitoneal cavernous hemangioma: A case report

Anastomosing hemangioma (AH) is rare and a newly recognized variant of capillary hemangioma that is mostly found in the genitourinary tract. Additionally, AH is sometimes difficult to diagnose without pathological specimens. It is difficult to diagnose preoperatively due to the lack of specific clinical and radiologic appearance. The present report describes the imaging features from a radiological perspective and outlines the clinicopathologic features and treatment options. A 67-year-old woman was referred to Dokkyo Medical University Saitama Medical Center (Koshigaya, Japan) for a retroperitoneal tumor that was identified at a medical checkup 4 years prior. The patient had no symptoms, no abnormal physical signs and no past medical or specific family history. Routine blood tests were all within the normal ranges. A nonenhanced CT scan showed a circular, homogenous, well-circumscribed retroperitoneal tumor that was ~32×23 mm in size, between the abdominal aorta and the inferior vena cava, and just below the left renal vein. On a contrast-enhanced multidetector CT scan, the tumor showed heterogeneous septal enhancement in the arterial phase and persistent enhancement in the portal phase. The tumor was diagnosed as a benign neurogenic tumor or a retroperitoneal cavernous hemangioma at the time, and the patient was intended to be followed up at the outpatient clinic. However, it gradually increased to a maximum diameter of 35 mm over 4 years. Finally, it was completely resected by open laparotomy and pathologically diagnosed as AH. Retroperitoneal hemangioma is extremely rare in adulthood and has been confirmed in only 1-3% of all retroperitoneal tumors. To the best of our knowledge, only 6 cases of para-aortic AH have been reported. The incidence of this variant is very low. However, AH may be included in the differential diagnosis when a slowly progressing heterogeneous mass appears in the para-aortic region that exhibits a CT-enhanced pattern similar to a typical cavernous hemangioma.

Anastomosing haemangioma of adrenal gland: an unusual vascular tumour

With only 15 reported cases, anastomosing haemangioma of adrenal is a rare entity and usually presents as adrenal incidentaloma. A hypertensive, diabetic, non-smoker man in his late 60s presented with irritative voiding symptoms. On evaluation, he was found to have a urinary bladder mass and left adrenal incidentaloma measuring 8 cm. Metabolic evaluation confirmed it to be non-functional.The patient underwent transurethral resection of bladder tumour with left laparoscopic adrenalectomy. Intraoperatively, the adrenal tumour was highly vascular with multiple feeder vessels. Grossly it was soft, encapsulated with focal grey-brown areas. Microscopically, most of adrenal gland was replaced by anastomosing proliferating capillary vessels within framework of non-endothelial supporting cells reminiscent of splenic sinusoids. The tumour was positive for CD-31, CD-34, Glut-1 and SMA.Anastomosing haemangioma is a benign entity but it must be differentiated from angiosarcoma. Characteristic imaging features are not yet defined and is, therefore, difficult to diagnose preoperatively.

Multimodal imaging features of retroperitoneal anastomosing hemangioma: a case report and literature review

Background

Anastomotic hemangioma is a rare subtype of capillary hemangioma primarily found in the genitourinary tract. We present a case of a patient with an anastomotic hemangioma located in the retroperitoneal space; then, we explore and summarize the imaging features from previously reported cases for accurate diagnosis.

Case presentation

A 57-year-old woman complained of left lower back pain. Contrast-enhanced ultrasound revealed a hypoechoic mass with "slow-in and slow-out" enhancement. Abdominal CT scan displayed a well-defined, round soft tissue mass in the right retroperitoneal region with obvious enhancement. MRI indicated low signal on T1-weighted imaging, high signal on T2-weighted imaging and diffusion-weighted imaging, and progressive enhancement after enhancement. Surgical removal of the tumor was performed. Histopathological examination exhibited a distinct tumor border with interconnected blood vessels and a cavity lined by a single layer of cubic endothelial cells. Immunohistochemistry confirmed the presence of CD31[+] and CD34[+]. The final pathological diagnosis was anastomotic hemangioma. No recurrence was observed during a 40-month follow-up.

Conclusion

Retroperitoneal anastomotic hemangioma is a rare and benign neoplasm that may be misdiagnosed as ectopic pheochromocytoma or angiosarcoma. This case report presents and analyzes the imaging characteristics of a series of retroperitoneal anastomotic hemangiomas, which can be valuable for future diagnoses and help prevent unnecessary surgeries.