Anastomosing Haemangioma of the Genitourinary Tract

Definition

A rare haemangioma variant of kidney and testis mimicking angiosarcoma.

Epidemiology

This is a tumour of adults.

Clinical features

Patients with renal lesion present with haematuria and vague pain. In the testes, presentation is with a palpable mass.

Radiology

Macroscopic appearances

Histopathology

The tumour has a peculiar anastomosing pattern reminiscent of both sinusoidal haemangioma and hobnail haemangioma (targetoid haemosiderotic haemangioma) of skin and soft tissues. Typically, there is an association with a medium-size vessel. The architecture is a loosely lobulated . There may be intravascular extension. There may be focal infiltration of surrounding tissues. The tumour consists of anastomosing sinusoidal capillary vessels. Vascular thrombi are typically present. The endothelial cells do not show multilayering. Scattered hobnail endothelial cells are seen and endothelial cells may contain striking hyaline globules. Mitoses are absent or rare. Any inflammatory infiltrate is limited to lymphocytes. Extra-medullary haematopoiesis may be prominent.

Immunohistochemistry

	CD34	1/11
	CD31	1/11
	FVIIIRA	2/21
	AE1/AE3	0/21
	EMA	0/11
	HMB45	0/11
	Placental alkaline phosphatase	0/11
	Human herpes virus type 8	0/11
	Human chorionic gonadotropin	0/11

Differential diagnosis

Retiform haemangioendothelioma: the margins are infiltrative; long arborising vessels form a retiform pattern and are lined by hobnail endothelial cells; there is usually a prominent lymphocytic infiltrate

Hobnail haemangioma; in the skin there are superficial dilated and deep dissecting vessels
Sinusoidal haemangioma: this variant of cavernous haemangioma lacks hobnail endothelial cells
Angiosarcoma: endothelial cells show multilayering and mitotic activity.

Prognosis

Benign

References

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