Angiomatosis

Angiomatosis is a descriptive term for diffuse, multifocal proliferation of blood vessels that results in numerous angiomas affecting the skin, mucosa, and sometimes internal organs. It is typically considered a vascular malformation or a spectrum of benign vascular lesions rather than a single tumor, and it can be congenital or acquired. The underlying process involves proliferation and dilation of small vessels, often with a lobular arrangement, leading to highly vascular lesions that may be widespread or clustered.

Clinical presentation varies with extent and sites involved. Cutaneous angiomatosis appears as widespread reddish papules or nodules on the skin and sometimes mucosal surfaces. Visceral angiomatosis involves organs such as the liver, spleen, bones, or central nervous system and can cause organ-specific symptoms or complications, including bleeding or impaired function. Some patients may be asymptomatic, particularly when the disease is limited to the skin.

Diagnosis relies on clinical assessment supported by imaging and, when necessary, histology. Ultrasound and MRI help delineate lesion distribution and vascularity, while CT can evaluate organ involvement. Biopsy may show benign-appearing endothelial proliferation with a lobular vascular pattern, though sampling carries bleeding risk in vascular lesions. Immunohistochemistry typically shows CD31 and CD34 positivity in vascular tissue. The differential diagnosis includes bacillary angiomatosis (in immunocompromised individuals), Kaposi sarcoma, angiosarcoma, and other vascular malformations.

Management is individualized. Asymptomatic or stable disease may be observed. Local therapies such as laser treatment, sclerotherapy, embolization, or surgical debulking can address disfiguring or function-impairing lesions. For extensive or visceral disease, systemic therapies including sirolimus or other targeted agents have been used. Prognosis depends on the extent and organ involvement, with localized disease generally carrying a better outlook than diffuse angiomatosis.