Congenital venous malformations consist of either localized or diffuse ectatic veins with abnormal collections of irregular venous channels. Although mostly in the skin, venous malformations are also commonly found in the cheek, tongue, lip, and mandible. They may be present in deep tissue, bone, muscle, or brain. Recently a loss-of-function mutation was discovered on the angiopoietin receptor gene TIE2/TEK in many solitary and multiple sporadic venous malformations [9]. In addition, upregulation of several factors including tissue growth factor beta (TGF-beta) and basic fibroblast growth factor (beta-FGF) has been also discovered in patients with venous malformations [10].

A venous malformation is always present at birth but is not always evident. They may first become noticeable in childhood or even adulthood and they do not spontaneously involute. Small lesions are usually asymptomatic or the patients may complain only of disfigurement. Intravascular coagulation due to trauma or venous stasis may sometimes cause pain. For large lesions with significant thrombosis, distal embolization may subsequently occur. When malformations are extensive, a blood coagulation profile should be performed. These patients are particularly at risk for a pulmonary embolus following surgery; they require anti-thromboembolic prophylactic treatment [11]. Trauma, infection, and hormone changes of puberty and pregnancy can be associated with growth of the lesions, probably because the progesterone receptors that have been discovered in these malformations [12, 13].

Superficial venous malformations have a bluish compressible mass with no palpable thrill or audible bruit. These lesions often enlarge in a dependent position or with Valsalva maneuver. Phleboliths are commonly seen on radiographs. Doppler echocardiography, MRI or MRA, and direct-puncture phlebography may be required to confirm the diagnosis and assess the extent of the lesion.

Treatment depends on the location and extent of the venous malformation. When a lesion is symptomatic, localized, and accessible, surgical excision remains one of the most superior treatment options and may offer a cure for localized lesions. Excision of complex lesions remains difficult due to intraoperative bleeding. Preoperative sclerotherapy (or sometimes multiple sessions of sclerotherapy) can be used prior to excision (24–48 h) to decrease surgical risk. Complete cure is not to be expected in patients with extensive disease but combined modality therapy may offer a long-term control of the disease. Superficial lesions or the superficial component of deep lesions can be treated with the Nd:YAG laser [14].

Arteriovenous fistulae or malformations (AVMs) are congenital vascular lesions associated with a variable degree of arteriovenous shunting. They are clinically evident in childhood or during puberty. Rapid expansion has been also reported following pregnancy and trauma, including inadequate surgical intervention. A defect in vascular stabilization is thought to cause AVM, but it remains unclear whether these lesions are primarily congenital in origin. An acquired AV fistula can also occur due to direct trauma to vessels; however, this is uncommon in the oral cavity.

The presentation of AVMs is commonly by a warm swelling with a palpable thrill and an audible bruit. Oral lesions can present early due to gingival involvement, disruption of deciduous teeth, and profuse periodontal bleeding. Traditional angiography or MRA to demonstrate their vascular anatomy is essential for confirming the diagnosis and developing a treatment plan. Moreover, CTA allows evaluation of local effects on surrounding tissues and bones and can define individual arterial feeders as well [15].

Treatment of AVMs could be problematic especially with large and diffuse lesions due to complete replacement of normal tissues by the diseased vessels. Such lesions require reconstruction after excision. Recurrence is also common after embolization or even after surgical excision due to recruitment of new vessels [16]. When a lesion is small and asymptomatic, a period of observation is often the most convenient initial strategy. Large and diffuse lesions are usually symptomatic and a delayed treatment may lead to cardiac decompensation. Intra–arterial embolization combined with surgical excision currently offers the best chance for cure. Excision is preformed 24–48 h after embolization. This helps control blood loss and defines the surgical margins of the lesion. Complete excision is sometimes impossible because of the location and extent of the malformation. Long-term follow-up with a dedicated multidisciplinary team is thus crucial for AVM management.

Lymphatic malformations, previously known as “cystic hygroma” or “lymphangioma,” are composed of dilated lymphatic vessels with inappropriate communication, lined by endothelial cells, and filled with lymphatic fluid. Their incidence is approximated to be 1 in 2000–4000 live births [17]. Lymphatic malformations are classically classified into macro-cystic, micro-cystic, or mixed according to the cyst size (2 cm³) [7]. What usually affect the oral cavity are the micro-cystic or mixed variants. These small non-compressible vesicles can weep and at times cause pain or minor bleeding. Micro-cystic disease usually carries a worse prognosis and could be more aggressive, invasive, and difficult to control [18].

Symptoms are usually related to the extent of the disease, which can be defined by MRI. The patient usually suffers from pain, dysphagia, and odynophagia.

As spontaneous resolution is usually not anticipated, management of symptomatic disease is usually mandatory. Treatment is usually easier and carries a more favorable prognosis with the macro-cystic type. Treatment modalities include sclerotherapy [19], carbon dioxide laser [20], and surgical excision (with/without reconstruction). Multiple combined treatment modalities are sometimes necessary for the disease control.

Dental ulcers are caused by trauma from a broken tooth or ill-fitting dentures. The ulcer occurs mostly at the side of the tongue. It is painful, with sloping serrated edges, elongated shallow floor covered with granulation tissue, and soft or mildly indurated base. It heals in few days when the cause is removed; otherwise it should be biopsied, particularly if malignancy is suspected. Treatment is by extraction of the ragged tooth plus good oral hygiene. Antibiotics are used if superadded infection occurs.

A frenular ulcer results from trauma of the frenulum of the tongue by the teeth during coughing in children with whooping cough, between 6 and 8 months of age (due to eruption of lower teeth). Treatment of the cause results in healing of the ulcer.

Herpetic ulcers are caused by herpes simplex (HS) virus in patients with low resistance (e.g., following pneumonia). They appear in the tongue and angles of the mouth as multiple, small, painful ulcers, preceded by vesicles.

Tuberculous ulcers result from active pulmonary TB or infected milk (causing ulcers, or diffuse fibrosis – woody tongue). They usually appear at the tip and sides of the tongue as multiple, painful, shallow ulcers with undermined edges, yellowish floor, and soft base. Treatment is by antituberculous drugs and sanitorial management.

During the first stage of syphilis, a chancre may occur at the tip of the tongue together with enlarged submental and submandibular LNs. During the second stage, mucous patches and snail track ulcers are present in the tongue (multiple and yellowish-white) associated with Hutchinson’s warts or condylomata. Gummatous ulcer develops during the third stage of syphilis, at the midline of the dorsum of the tongue. It is painless, single, with clear-cut edges and washleather floor. Leukoplakia of diffuse fibrosis may also be present.

Chronic superficial glossitis may be associated with chronic repeated nonspecific ulcers, usually on the dorsum of the tongue. Ulcers are superficial, small, and painful. They are associated with fissures or vesicles and have a unilateral distribution. Untreated chronic superficial glossitis may lead to leukoplakia, erythroplakia, or overt squamous cell carcinoma (SCC). Treatment includes avoiding the predisposing factors, mouth gargles, close follow-up, and biopsy of any developing lesions.