Atypical location of a lymphangioma in the thymic cavity in an adult: case report and review of the literature

Introduction : Lymphangiomas are rare primary tumours of the anterior mediastinum in adults. They are usually asymptomatic. In other cases, there may be a cervical mass or signs of mediastinal compression such as exertional dyspnoea or dysphagia. The diagnosis is made with certainty by histology. Surgery is the main curative treatment. Case report : We report the case of a 34-year-old female patient who presented with a painless anterior cervico-mediastinal mass associated with dyspnoea. Cervico-thoracic imaging revealed a non-compressive mass in the thymic cavity, suggestive of a thymoma but not excluding a lymphoma. Biology and histology after scannoguided biopsy were negative. Further histological examination following surgical biopsy revealed the vascular nature of the mass, consistent with lymphangioma. Conclusion : Lymphangiomas are rarely seen in adults, particularly in the anterior mediastinum. Our observation of a lymphangioma found in the thymic cavity adds to the other cases found in the literature. This could lead us to include it in the nosological panel of an anterior cervico-mediastinal mass found in adults. Furthermore, as its diagnosis is essentially histological, we could also consider surgery as a means of diagnosis in addition to the therapeutic aspect, especially in cases of diagnostic doubt.