Renal Anastomosing Hemangioma Simulating Angiosarcoma as a Second Primary in a Patient with Breast Cancer

Anastomosing hemangioma is a type of tumor lesion of benign behavior scarcely documented, it has been observed in renal parenchyma, testicles, ovaries and adrenal glands, it is usually prone to perirenal and renal medul-lary adipose tissue. In this case report, we present an anastomosed hemangioma in the right kidney of a 33-year-old woman, with previous coexistence of breast cancer, in which an unusual behavior was detected, with characteristics of vascular lesion, in this case we report: The classic conditions, its heterogeneous nature and the vascular alterations that presents in different imaging modalities.


Introduction
Hemangiomas are common mesenchymal tumors, which manifest mainly on the skin, soft tissues, and viscera. The existence of reports about renal vascular tumors is scarce, the literature of angiosarcomas and hemangiomas are limited to some series of reports and clinical cases, even when renal vascularity is considerable, receiving 20% of cardiac output [1].
Anastomosing hemangioma is a tumor-like lesion of vascular etiology and benign behavior [2]. It was first described in 2009 by Montgomery and Epstein as a vascular lesion that involves the renal parenchyma and mimics angiosarcoma.
The composition of this type of hemangioma is characterized by irregularly anastomosed sinusoidal vascular spaces, surrounded by endothelial cells with mi-

Image Assessment
The diagnostic through ultrasonography has a limited literature, because anastomosing hemangioma is a variable type of tumor lesion, and ultrasound examination usually shows different echogenicity ranges [7]. In our case report, a tumor-type lesion is documented with a slight increase in echogenicity, compared to the renal parenchyma, associated with calcifications and peripheral vascularity ( Figure 1).
By means of computed tomography, hemangiomas are described as neoplasms with a circular appearance, with a low heterogeneous density of soft tissues, in the arterial phase they usually manifest a septal enhancement that persists during the venous phase [8].
Considering the characteristics detected by renal magnetic resonance imaging, anastomosing hemangioma is described as a lesion with a rounded, well-defined morphology [9], hypointense in T1 sequence and hyperintense in T2 sequence, and with substantial enhancement to the contrast medium [8].

Case Report
33-year-old woman with a three-year history of breast cancer; the patient received an initial treatment of four cycles of chemotherapy (epirubicin); subsequently, on December 2 nd of 2017, a radical mastectomy with axillary dissection was performed. Afterwards, a histopathological diagnosis of infiltrating ductal carcinoma was carried out, indicating a positive molecular subtype for estrogen and progesterone receptors.
In September of 2020, after 37 sessions of radiotherapy, she was monitored in order to provide follow-up; by means of thoracoabdominal computed tomography, with simple and contrasted phases; some characteristics of metastasis, local and generalized lymphadenopathy were found, as well as lesions suggestive of secondary deposits in the abdominal wall; as a discovery, a tumor lesion with soft tissue density was found in the lower pole of the right kidney, which has an appreciable enhancement to contrast in arterial phase, therefore, by means of the known diagnostic methods it was conjectured in mammary metastasis to the kidney, with a second primary lesion (angiosarcoma) ( Figure 2). Consequently, and due to the suspicion of a neoplastic process, the case was considered as a secondary deposit of a known primary by the oncology service.
In April of 2021, we optimized the acquisition method and computed tomography protocol, in this case report, we found that the renal lesion has a vascular compartment to the intravenous contrast, without changes in size and morphology, so it is considered indicative of benignity ( Figure 2).
In complementation, an MRI was also performed, revealing an image with a

Discussion
Renal tumors of vascular origin are unusual, the most frequent subgroup consisting of benign hemangiomas.
Renal hemangiomas are usually detected in incidental circumstances and asymptomatic patients. In the symptomatic patient, the regular symptoms are hematuria and abdominal pain [10].
In the global knowledge, it is estimated that 200 cases are reported, but with limited radiological findings [1], consequently, we have a limited information about the radiological characteristics of the condition; although there are cases reported with erroneous diagnoses of renal cell carcinomas or angiosarcomas, a renal hemangioma appearing to be a metastasis deposit or a second primary tumor has not been specified in a patient with breast cancer [2].
According to the literature, renal hemangiomas generally have the presence of small or large injuries, with an average size of 2.1 centimeters, and a range of 1 to 6 centimeters [7] [11].
In this report, through ultrasonography, a well-defined tumor-like lesion with presence of peripheral vascularity was observed, which was achieved with the help of color Doppler (Figure 1). By means of computed tomography, a predominantly hypodense heterogeneous lesion with internal calcifications and with a substantial heterogeneous enhancement with vascular features (Figure 2). With the help of magnetic resonance imaging, a mixed intensity pattern with hyperintense areas in T2 and hypointense in T1 areas were detected in the lower pole of the right kidney ( Figure 3). The imaging findings correspond to those reported in the literature [2] [4].
The differential diagnoses between benign and malignant vascular tumors is realized by histopathology [4], in this case, the possibility of an angiosarcoma or metastasis of the known primary was ruled out, by virtue of a later tomography performed to evaluate the therapeutic response, an improvement in the contrast Regardless of the fact that anastomosing hemangioma is uncommon, its identification and separation from other malignant entities is essential, because a meticulous diagnosis offers the opportunity to provide a conservative treatment using selective embolization, in comparison to the use of a radical nephrectomy, which is often chosen as treatment [2].
Histopathological analysis reveals in this kind of tumor lesions, the presence of intravascular growth of the hemangioma, multilayers of cellular endothelium, and an absence of cellular atypia. It was determined to obtain biopsy by percutaneous needle puncture, taking into consideration the vascular pattern, the risk was reduced with the help of color Doppler, however, the result was not the convenient one, and only the increase of the level of vascular hyperplasia from mild to moderate with a compromise of 20% of the vascular lumen of the arterioles close to the glomerular hilum was documented (Figure 4).

Conclusions
Due to the fact that hemangioma is a barely reported disease, all the documentation of the general and radiological features detected by ultrasound, computed tomography and magnetic resonance imaging are very helpful. In addition, the prior coexistence of stage IV metastatic breast cancer is a consideration when relating and clarifying the diagnosis with histopathologic analysis. Although most reports are obtained through surgical procedures via partial or total nephrectomy, in this case report, it was determined to use an ultrasound-guided needle biopsy, which proved to be a convenient alternative, considering that in addition to being an affordable medical treatment, it offers results in less time, since it reduces a medical care process that for various circumstances can be delayed, finally, we consider this alternative less invasive, also leaves little or no scarring, and does not require exposure to ionizing radiation.
To our knowledge, this is one of the first reports in which ultrasonography, computed tomography and magnetic resonance imaging are documented in the same patient. We hope that this information will be useful in the clinical and radiological field, helping in the identification of subsequent renal hemangiomas.