Mitral regurgitation due to a mediastinal desmoid tumor: A case report and review of the literature

Abstract

Desmoid tumors are rare benign tumors that arise most commonly in the abdomen, but can occasionally appear in extra-abdominal sites. We present a 3-year-old girl with mitral regurgitation in whom the final diagnosis was a mediastinal desmoid tumor. We managed the patient with complete surgical resection with an uneventful follow-up. Desmoid tumors are rare benign soft-tissue tumors that consist of proliferated, well-differentiated fibroblasts. They represent only 0.03% of all tumors, and their incidence is between 1 and 4 per million population annually. 1 Most patients are between 15 and 60 years old, and they affect women more commonly than men. 2 Desmoid tumors are locally aggressive and often recur even after complete resection, but they do not metastasize. 2 Desmoid tumors most commonly arise in the abdomen, but can occasionally appear in extra-abdominal sites such as chest wall, shoulder, mediastinum, and other rare sites. 3 We report a case of a 3-year-old girl with a mediastinal desmoid tumor and a thorough review of the literature to summarize the characteristics of mediastinal desmoid tumors. 2 | CASE PRESENTATION A 3-year-old girl presented to the hospital with a 4-month history of dry cough and dyspnea. Her past medical and surgical history was unremarkable. On physical examination, there was mild-to-moderate dyspnea without cyanosis or pallor. Chest examination showed diminished breath sounds on the right side with a respiratory rate of 44/min and an oxygen saturation of 95%. Heart rate was 136/min, blood pressure was 100/70 mm Hg, and there was a pansystolic murmur heard in the mitral area graded 3/6. The abdomen was tender, and the liver was displaced inferiorly about 6 cm below the costal margin without splenomegaly or venous dilations on the abdominal wall. Laboratory tests revealed abnormal levels of CRP (8 mg/L), ESR (31 mm/h), K + (3.4 mmol/L), and urea (32 mg/dL). Other laboratory tests, including tumor markers, were unremarkable. Chest X-ray (CXR) revealed a homogeneously increased density over the entire right side of the chest, shifting the mediastinum to the left, as seen in Figure 1.