JCDA Jan 2014 | Page 40

jcda J Can Dent Assoc 2013;79:d88 ca ESSENTIAL DENTAL KNOWLEDGE Published by The Canadian Dental Association Figure 3: Higher magnification of the connective tissue showing the numerous lymphatic vessels (hematoxylin and eosin, magnification 40×). common site of oral lymphatic malformations. 2,4-9 Other less commonly affected intraoral sites are the buccal mucosa, lips, soft and hard palates, floor of the mouth, retromolar pad, tonsils and gingiva.4,6-8 Few cases of lymphatic malformations on gingival tissue have been reported in the literature. Review of the Literature Until the 1900s, lymphatic malformations were considered neoplastic.10 Nowadays, they are viewed as rare benign congenital anomalies 6,7,10 and are typically diagnosed during childhood. 5,7,9,10 Acquired lymphangiectasia refers to a specific type of lymphatic malformation that develops as a result of an infection or surgery that interferes with regional lymphatic drainage.1,3,4 The first case of lymphatic malformation was described by Redenbacher in 1828.10 Nearly 15  years later, Wernher proposed the term "hygroma" to identify this type of lesion. He then developed a histologic classification of lymphangiomas based on 3  categories: capillary (simplex), cavernous and cystic (cystic hygroma).10 Although arbitrary, this classification is still used by some authors, 2 while others suggest using the term lymphatic malformation.10 Another classification divides lymphatic malformations into 2 categories: microcystic lymphatic malformations and macrocystic lymphatic malformations. The microcystic form includes lymphangioma simplex and circumscriptum, while the macrocystic form includes cavernous lymphangiomas and cystic hygromas.7,11 However, some authors suggest that histologic differences in the various types of lymphatic malformations may be attributed to anatomic location, making such classification of little interest.1,4 Lymphangiomas have a marked predilection for the head and neck, with 50–75% of all cases occurring in these regions.2,7 Although lymphatic malformations are always present at birth, they may • 40 • not be clinically identifiable until they develop or a complication makes them more apparent.11 The first symptoms may occur following an infection, DES CONNAISSANCES DENTAIRES INDISPENSABLES bleeding or lymphatic leakage.11 Approximately l’Association dentaire 50% of lymphangiomas are visible at birth canadienne and up to 90% are visible by age  2 years2; 95% of oral lymphangiomas are present before age 10 years.5 Lymphatic malformations are less common in late childhood and rare in adults.7 Men and women are affected equally.7,9 The malformations may vary in dimension from capillary size to several centimetres.7 Cavernous lymphangiomas, unlike cystic hygromas, are more commonly found in the oral cavity.2 Connective tissue and skeletal muscles in the oral cavity limit vessel expansion.2 In general, the lesion is superficial and its surface is characterized by a cluster of translucent vesicles resembling tapioca pudding or frog eggs.2 A secondary hemorrhage in the lymphatic spaces may account for the vesicles’ purple colour.2,3 The clinical appearance of the surface of the lesion is due to numerous thin-walled cavities and dilated vessels directly beneath the mucous membrane.7 Deeper lesions present as poorly defined masses.2 Intraoral lymphatic malformations on gingival tissues are extremely rare. 5-7 Kalpidis and colleagues7 reported a case of a solitary superficial microcystic lymphatic malformation confined to the gingiva. According to these authors, this is the first case reported in the literature. Three other cases of lymphangiomas confined to the gingiva have been described,1,4,8 but the lesions were bilateral. Small lymphangiomas measuring less than 1  cm can be observed on the alveolar ridge in approximately 4% of black newborns. 2 These lesions are often bilateral on the mandibular ridge. They occur in twice as many male infants as female. Most resolve spontaneously, as they are not seen in adults. Some authors believe that congenital lymphangioma of the alveolar ridge seen in African-American newborns is a distinct lesion.4 The standard treatment for lymphatic malformations is surgical excision. 2,10 Ablation of these lesions requires a reasonably wide resection margin, as superficial ablation frequently results in recurrence.7 However, other therapeutic modalities include conservative surgical excision followed by periodic examination to monitor for recurrence,1 jadc Publié par | 2014 | Vol. 80, No. 1 | jcda ca ESSENTIAL DENTAL KNOWLEDGE Published by The Canadian Dental Association jcdaf ca