2020-8 / FEBRUARY 24

43 year old female with a 1.7cm renal cortical mass found incidentally on imaging.


1. What is the correct diagnosis?

a. Clear cell renal cell carcinoma

b. Hemangioblastoma

c. Anastomosing hemangioma

d. Angiosarcoma

1. Anastomosing hemangioma

Sections show a well circumscribed mass composed of anastomosing sinusoidal capillary sized vessels with bland appearing endothelial cells. There is no significant atypia, necrosis or mitotic activity. There is focal fibrin deposition.
Anastomosing hemangioma is a variant of hemangioma that is uncommon but well documented in the genitourinary organs, such as the kidney, ovary, and testis. In the kidney, they usually present as a solitary lesion involving the renal cortex. The differential diagnosis includes clear cell renal cell carcinoma with prominent sinusoid-like vasculature, hemangioblastoma and angiosarcoma. Lack of an epithelial component in this case excludes renal cell carcinoma. The vacuolated stromal cells characteristic of hemangioblastoma are missing. Angiosarcoma is also ruled out, given that this lesion shows no cytological atypia, mitotic activity nor necrosis. Anastomosing hemangiomas are benign and cured by excision.

R1. Montgomery E, Epstein JI. Anastomosing hemangioma of genitourinary tract: a lesion mimicking angiosarcoma.
Am J Surg Pathol (Sept); 33: 1364-9, 2009.

2. Kryvenko ON, Gupta NS, Meier FA, Lee MW, Epstein JI. Anastomosing hemangioma of the genitourinary system: 8 cases in the kidney and ovary with immunohistochemical and ultrastructural analysis.
Am J Clin Pathol (September) 136: 450-7, 2011.

Leili Mirsadraei
NYU Langone Health/NYU Winthrop Hospital