Solitary superficial microcystic lymphatic malformation (lymphangioma circumscriptum) of the gingiva

Background: Lymphatic malformations are uncommon, hamartomatous, developmental aberrations of the lymphatic system. The case presented in this report is a rare solitary gingival involvement of a microcystic-type lymphatic malformation. Methods: The lesion presented clinically as a small vesicular swelling of a buccal interdental papilla in a 16-year-old girt. Involved tissues were excised and submitted for routine histologic examination. The expression of the endothelial marker CD34 was investigated using immunohistochemical staining. Results: A physical examination failed to reveal similar or other abnormalities elsewhere in the body of the patient, including the oral cavity. Histopathologic analysis of the specimen demonstrated the presence of subepithelial, thin-walled, distended vascular cavities forming confluent vesicles containing lymph. The dilated lymphatic formations were lined by flattened CD34-negative endothelial cells. These features were consistent with a microcystic gingival lymphatic malformation. To the best of our knowledge, only two additional reports of this malformation have been published to date, but both presented with bilateral gingival involvement. Conclusion: Even though lymphatic malformations are encountered very infrequently on gingiva, they should be considered in the differential diagnosis of related conditions with a vesicular clinical appearance.