Vascular Lesions in Childhood - What You See Is Not Always What You Get

    

    

    Figure 4:  A post-operative photo revealing resection of the vascular lesion.
    
    

Discussion

Vascular lesions in the pediatric population are a common presentation, and are classically divided into two categories – hemangiomas and malformations [1,2]. IHs are benign tumors of vascular tissue that exhibit abnormal endothelial cell proliferation [2,3]. IHs are not present at birth, undergo a course of growth and subsequent involution with a regression onset by one year of life [2,5]. IHs can be located anywhere on the body, and can affect various organs thus raising the concern for significant consequences [2]. Vascular malformations are thought to be a result of an interruption at a particular stage of vessel development [1,6]. Malformations are products of morphogenesis errors and subsequent vascular channel abnormalities [1]. Distinctively, malformations are characteristically present at birth, grow along with the child and regression typically does not occur [1,6]. The lesion found on examination of the presented patient was not present at birth, similar to IHs, yet continued to grow showing no signs of regression which are characteristic findings in vascular malformations. Both hemangiomas and malformations have overlapping similarities yet, characteristically unique differences.

Infantile hemangiomas can be clinically classified as localized, segmental, or indeterminate lesions [3,5]. Localized lesions are more common, they arise from a single focus, and are clearly well-defined [3,5]. Segmental lesions present as a patch or plaque-like lesion that is distributed over a cutaneous territory [3,5]. Segmental lesions carry a higher complication rate and are most often seen in the Hispanic population [3,5]. Chiller et al., have reported that the anterior cheek is the most commonly involved anatomical segment in the population they studied, followed by the forehead of the infant [3]. Grossly, IHs can be described as superficial, deep, or combined. Superficial IHs are most common, and hence the name they appear as a plaque like nodule or bright red papule lying above normal skin [5]. These lesions take on names such as “capillary” or “strawberry” hemangiomas [7,8].

There are several complications associated with His [3,5]. Ischemic ulceration secondary to venous hypertension is the most common complication [3,5]. Other notable complications include pain, infection, airway compromise and hemorrhage that can lead to high-output cardiac failure [3,5]. The presentation of more than five cutaneous “strawberry” hemangiomas can be associated with a hepatic hemangioma, which warrants further workup to prevent potential life threatening high-output cardiac failure [8]. A segmental IH with periorbital involvement, or one which presents on the head and neck are closely associated with syndromes such as PHACE [3,5,9]. The associated abnormalities include (posterior fossa brain malformations, hemangiomas, arterial anomalies, coarctation of the aorta, other cardiac defects, and eye abnormalities) [3,5,9]. When the abnormalities of this syndrome include urogenital abnormalities or spinal involvement the collection of symptoms is referred to as LUMBAR syndrome [5,9]. There are several other cutaneous vascular anomalies that can undergo a benign, locally aggressive, or malignant course [5,9]. Congenital hemangiomas, tufted angioma, pyogenic granuloma are generally rare and benign. More notably there is Kaposi sarcoma, a locally aggressive vascular tumor, and angiosarcoma, a malignant tumor of endothelial cells [5,9]. The patient presented in this case did not present with other notable abnormalities suggestive of these syndromes.

AVMs are classified based on the primary aberrant vessel type: arterial, venous, capillary or venulocapillary, lymphatic or mixed [5,8]. The most common examples of capillary, or venulocapillary malformations include “nevus flammeus” and “port wine stain.” Malformations of venous etiology are loosely termed “cavernous hemangioma” and “venous hemangioma” however, cavernous hemangioma has also been used to refer to deep, or subcutaneous hemangiomas, and thus clinicians typically avoid its usage [5,8]. Vascular flow characteristics (i.e., slow-flow or fast-flow) are also used to classify vascular malformations [6]. Capillary, lymphatic, and venous malformations are characteristically slow-flow in nature, while arterial and arteriovenous malformations make up fast-flow malformations [6].

Almost always present and detected initially in infancy, AVMs typically remain quiescent during childhood [1]. The Schobinger classification describes the different stages of arteriovenous malformations from the less severe stage I (quiescence) to the more severe stage IV (decompensation) (Table 1) [6]. Malformations have the tendency of compressing surrounding tissues with ensuing pain, and functional impairment [6]. Clinical findings in AVMs vary from warm, pink-bluish stains with shunting on Doppler to ulceration, bleeding, tissue necrosis and most severely cardiac failure [6]. Cardiac failure is a result of hemodynamic dysfunction that leads to a “steal phenomenon” and subsequent life-threatening hemorrahages [6].

  

    
Stage
    
Clinical Finding
  
  

    
I (quiescence)
    
Warmth, pink-bluish stains, shunting on Doppler. Arteriovenous    malformation can mimic capillary or involuting hemangioma
  
  

    
II (expansion)
    
Enlargement, pulsation, thrill, bruit, tortuous tense veins
  
  

    
III (destruction)
    
Dystrophic skin changes, ulceration, bleeding, pain or tissue    necrosis. Bony lytic lesion can occur
  
  

    
IV (decompensation)
    
Cardiac failure
  

Table 1: The Schobinger Staging of AV Malformations [6].