Cases of lymphangioma are diagnosed by histopathologic inspection. In prenatal cases, cystic lymphangioma is diagnosed using an ultrasound; when confirmed amniocentesis may be recommended to check for associated genetic disorders.

Diagnosis is generally made by magnetic resonance imaging (MRI), particularly using a specific imaging technique known as a gradient-echo sequence MRI, which can unmask small or punctate lesions that may otherwise remain undetected. These lesions are also more conspicuous on FLAIR imaging compared to standard T2 weighing. FLAIR imaging is different from gradient sequences. Rather, it is similar to T2 weighing but suppresses free-flowing fluid signal. Sometimes quiescent CCMs can be revealed as incidental findings during MRI exams ordered for other reasons. Many cavernous hemangiomas are detected "accidentally" during MRIs searching for other pathologies. These "incidentalomas" are generally asymptomatic. In the case of hemorrhage, however, a CT scan is more efficient at showing new blood than an MRI, and when brain hemorrhage is suspected, a CT scan may be ordered first, followed by an MRI to confirm the type of lesion that has bled.

Sometimes the lesion appearance imaged by MRI remains inconclusive. Consequently neurosurgeons will order a cerebral angiogram or magnetic resonance angiogram (MRA). Since CCMs are low flow lesions (they are hooked into the venous side of the circulatory system), they will be angiographically occult (invisible). If a lesion is discernible via angiogram in the same location as in the MRI, then an arteriovenous malformation (AVM) becomes the primary concern.

Gradient-Echo T2WI magnetic resonance imaging (MRI) is most sensitive method for diagnosing cavernous hemangiomas. MRI is such a powerful tool for diagnosis, it has led to an increase in diagnosis of cavernous hemangiomas since the technology's advent in the 1980s. The radiographic appearance is most commonly described as "popcorn" or "mulberry"-shaped. Computed tomography (CT) scanning is not a sensitive or specific method for diagnosing cavernous hemangiomas. Angiography is typically not necessary, unless it is required to rule out other diagnoses. Additionally, biopsies can be obtained from tumor tissue for examination under a microscope. It is essential to diagnose cavernous hemangioma because treatments for this benign tumor are less aggressive than that of cancerous tumors, such as angiosarcoma. However, since MRI appearance is practically pathognomonic, biopsy is rarely needed for verification.

The prognosis for lymphangioma circumscriptum and cavernous lymphangioma is generally excellent. This condition is associated with minor bleeding, recurrent cellulitis, and lymph fluid leakage. Two cases of lymphangiosarcoma arising from lymphangioma circumscriptum have been reported; however, in both of the patients, the preexisting lesion was exposed to extensive radiation therapy.

In cystic hygroma, large cysts can cause dysphagia, respiratory problems, and serious infection if they involve the neck. Patients with cystic hygroma should receive cytogenetic analysis to determine if they have chromosomal abnormalities, and parents should receive genetic counseling because this condition can recur in subsequent pregnancies.

Complications after surgical removal of cystic hygroma include damage to the structures in the neck, infection, and return of the cystic hygroma.

In the treatment of a brain cavernous hemangioma, neurosurgery is usually the treatment chosen. Research needs to be conducted on the efficacy of treatment with stereotactic radiation therapy, especially on the long-term. However, radiotherapy is still being studied as a form of treatment if neurosurgery is too dangerous due the location of the cavernoma. Genetic researchers are still working on determining the cause of the illness and the mechanism behind blood vessel formation. Clinical trials are being conducted to better assess when it is appropriate to treat a patient with this malformation and with what treatment method. Additionally, long term studies are being conducted because there is no information related to the long-term outlook of patients with cavernoma. A registry exists known as The International Cavernous Angioma Patient Registry collects information from patients diagnosed with cavernoma in order to facilitate discovery of non-invasive treatments.

Oral propranolol appears to be the most effective treatment for reducing the size of capillary hemangiomas in children and is more effective than placebo, observation without intervention, or oral corticosteroids.

The incidence in the general population is roughly 0.5%, and clinical symptoms typically appear between 20 to 30 years of age. Once thought to be strictly congenital, these vascular lesions have been found to occur "de novo". It may appear either sporadically or exhibit autosomal dominant inheritance.

Spider angiomas are asymptomatic and usually resolve spontaneously. This is common in the case of children, although they may take several years to disappear. If the spider angiomas are associated with pregnancy, they may resolve after childbirth. In women taking oral contraceptives, they may resolve after stopping these contraceptives. The spider angiomas associated with liver disease may resolve when liver function increases or when a liver transplant is performed.

For spider angiomas on the face, techniques such as electrodesiccation and laser treatment can be used to remove the lesion. There is a small risk of a scar, although the results are generally good. Spider angiomas can recur after treatment.

Littoral cell angiomas show in CT scans. They are diagnosed by pathologists by taking a sample of the tumour via Fine Needle Aspiration or Core Needle Aspiration or from a splenectomy. Histologically, they have anastoming small vascular channels and cystic spaces with papillary projections.

In most patients, the number and size of cherry angiomas increases with advancing age. They are harmless, having no relation to cancer at all.

A capillary hemangioma (also known as an Infantile hemangioma, Strawberry hemangioma, and Strawberry nevus) is the most common variant of hemangioma which appears as a raised, red, lumpy area of flesh anywhere on the body, though 83% occur on the head or neck area. These marks occur in about 10% of all births, and usually appear between one and four weeks after birth. It may grow rapidly, before stopping and slowly fading. Some are gone by the age of 2, about 60% by 5 years, and 90–95% by 9 years. Capillary hemangioma is a vascular anomaly.

Capillary hemangiomas occur 5 times more often in female infants than in males, and mostly in Caucasian populations. Additionally, low birthweight infants have a 26% chance of developing a hemangioma.

It is the most common tumor of orbit and periorbital areas in childhood. It may occur in the skin, subcutaneous tissues and mucous membranes of oral cavities and lips as well as in the liver, spleen and kidneys. While this birthmark may be alarming in appearance, physicians generally counsel that it be left to disappear on its own, unless it is in the way of vision or blocking the nostrils.

These lesions generally do not require treatment. If they are cosmetically unappealing or are subject to bleeding angiomas may be removed by electrocautery, a process of destroying the tissue by use of a small probe with an electric current running through it. Removal may cause scarring. More recently pulsed dye laser or intense pulsed light (IPL) treatment has also been used.

Future treatment based on a locally acting inhibitor of MEK1 and Cyclin E1 could possibly be an option. A natural MEK1 inhibitor is myricetin

The Cognard et al. Classification correlates venous drainage patterns with increasingly aggressive neurological clinical course.

Prognosis depends on the size and location of the tumour, untreated angiomatosis may lead to blindness and/ or permanent brain damage. Death may occur, with complications in the kidney or brain.

This is based on MRI scan, magnetic resonance angiography and CT scan. A cerebral digital subtraction angiography (DSA) enhances visualization of the fistula.

- CT scans classically show an enlarged superior ophthalmic vein, cavernous sinus enlargement ipsilateral (same side) as the abnormality and possibly diffuse enlargement of all the extraocular muscles resulting from venous engorgement.

- Selective arteriography is used to evaluate arteriovenous fistulas.

- High resolution digital subtraction angiography may help in classifying CCF into dural and direct type and thus formulate a strategy to treat it either by a balloon or coil or both with or without preservation of parent ipsilateral carotid artery.

Angiomatosis is a non-neoplastic condition characterised by nests of proliferating capillaries arranged in a lobular pattern, displacing adjacent muscle and fat. It consists of many angiomas.

These tend to be cavernous hemangiomas, which are sharply defined, sponge-like tumors composed of large, dilated, cavernous vascular spaces.

The surgical treatment involves the resection of the extracranial venous package and ligation of the emissary communicating vein. In some cases of SP, surgical excision is performed for cosmetic reasons. The endovascular technique has been described by transvenous approach combined with direct puncture and the recently endovascular embolization with Onyx.

Treatment is varied and depends on the site and extent of tumor involvement, site(s) of metastasis, and specific individual factors. Surgical resection, radiotherapy, and chemotherapy have all been used to treat these masses, although studies on survival have yet to be conducted to delineate various treatment regimens.

Cerebral angiography is the diagnostic standard. MRIs are usually normal.

Computed tomography (CT scan): A CT scan may be normal if it is done soon after the onset of symptoms. A CT scan is the best test to look for bleeding in or around your brain. In some hospitals, a perfusion CT scan may be done to see where the blood is flowing and not flowing in your brain.

Magnetic resonance imaging (MRI scan): A special MRI technique (diffusion MRI) may show evidence of an ischemic stroke within minutes of symptom onset. In some hospitals, a perfusion MRI scan may be done to see where the blood is flowing and not flowing in your brain.

Angiogram: a test that looks at the blood vessels that feed the brain. An angiogram will show whether the blood vessel is blocked by a clot, the blood vessel is narrowed, or if there is an abnormality of a blood vessel known as an aneurysm.

Carotid duplex: A carotid duplex is an ultrasound study that assesses whether or not you have atherosclerosis (narrowing) of the carotid arteries. These arteries are the large blood vessels in your neck that feed your brain.

Transcranial Doppler (TCD): Transcranial Doppler is an ultrasound study that assesses whether or not you have atherosclerosis (narrowing) of the blood vessels inside of your brain. It can also be used to see if you have emboli (blood clots) in your blood vessels.

CBC, ESR, blood cultures, and sinus cultures help establish and identify an infectious primary source. Lumbar puncture is necessary to rule out meningitis.

DVA can be diagnosed through the Cerebral venous sinus thrombosis with collateral drainage. DVA can also be found diagnosed with Sturge–Weber syndrome and can be found through leptomeningeal angiomatosis. Demyelinating disease has also been found to enlarge Medulla veins.

Sinus films are helpful in the diagnosis of sphenoid sinusitis. Opacification, sclerosis, and air-fluid levels are typical findings. Contrast-enhanced CT scan may reveal underlying sinusitis, thickening of the superior ophthalmic vein, and irregular filling defects within the cavernous sinus; however, findings may be normal early in the disease course.

A MRI using flow parameters and an MR venogram are more sensitive than a CT scan, and are the imaging studies of choice to diagnose cavernous sinus thrombosis. Findings may include deformity of the internal carotid artery within the cavernous sinus, and an obvious signal hyperintensity within thrombosed vascular sinuses on all pulse sequences.

Cerebral angiography can be performed, but it is invasive and not very sensitive. Orbital venography is difficult to perform, but it is excellent in diagnosing occlusion of the cavernous sinus.

LCAs most often are not clinically detectable. On occasion, their first presentation may be with splenic rupture.

Most patients show no symptoms and the tumours are found incidentally.

Liver haemangiomas are typically hyperechoic on ultrasound though may occasionally be hypoechoic; ultrasound is not diagnostic. Computed tomography (CT), magnetic resonance imaging (MRI) or single-photon emission computed tomography (SPECT) using autologous labelled Red Blood Cells (RBC) with Tc-99m is diagnostic. Biopsy is avoided due to the risk of haemorrhage.

Hepatic haemangiomas can occur as part of a clinical syndrome, for example Klippel-Trenaunay-Weber syndrome, Osler–Weber–Rendu syndrome and Von Hippel-Lindau syndrome.