Sublingual Lymphangioma Mimicking a Ranula: A Case Report ^†

1. Background

Lymphangiomas are benign congenital malformations arising from the lymphatic system. A hamartomatous nature has been claimed for this heterogeneous cluster of disease, which is characterized by abnormal development of lymph nodes, leading to lymph collection and subsequent swelling [1,2]. In particular, in the head and neck district lymphangiomas occur with high frequency, representing almost 75% of cases. Orofacial lymphangiomas can be congenital, or develop by two years of age. The submandibular space and the posterior triangle of the neck are the most affected regions, followed by parotid area, tongue, and floor of the mouth [3]. The lesions are generally characterized by slow growth, although rapid enlargement can be observed in cases of infection or trauma. As a peculiar characteristic, lymphangiomas do not tend to spontaneous regression, often making necessary a surgical approach to the lesion, due to an impairment in function and aesthetics.

2. Case Report

A 11-year-old female patient was referred to the Unit of Dentistry and Oral Surgery, University of Pisa, for the development of a moderate swelling of the mouth floor. At clinical examination, the patient showed an asymptomatic tumefaction involving the right side of the mouth floor, causing lingual displacement (Figure 1). Considering medical history, the patient was affected by juvenile idiopathic arthritis, and was under pharmacological treatment with methotrexate and adalimumab. Several pathologic conditions entered differential diagnosis. However, sublingual ranula was strongly suspected due to the localization and the rapid development of the lesion [4].

Head and neck MR was performed to better investigate the lesion, revealing the presence of a large mass occupying the right half of the mouth floor, and characterized by hyperintensity in T2 (Figure 2).

Initially, surgical approach was performed, with the marsupialization of the lesion and bioptic sampling. Histology revealed the presence of lymphatic channels in a connective tissue stroma, characterized by focally disorganized and thinned epithelium, and peripheral lymphoid aggregates.

Second surgery with the complete removal of the lesion was then performed. At 6-month follow-up, no signs of recurrence were observed.

3. Conclusions

Lymphangiomas usually develop early in childhood. In this peculiar case, lymphangioma developed in a 11-year-old patient, showing sudden presentation and rapid enlargement. Histology was fundamental in discriminating the nature of the lesion. Surgical approach lead to resolution of the case and complete healing at 6 months, consistently with the non-recurring nature of the disease.