Prenatal ultrasonic features of a mediastinal teratoma: A case report and literature review

Abstract

Fetal mediastinal teratomas represent only 10% of congenital teratomas in children and 2.6% of all mediastinal masses in children. Teratomas have multifactorial etiology, such as chromosomal abnormalities. Fetal mediastinal teratomas are rare. Mediastinal teratomas can cause hydrops fetalis, fetal demise, and neonatal respiratory distress; therefore, accurate perinatal management and interventions are very important. We describe a case of fetal mediastinal teratoma wherein the cystic fluid in the fetal tumor was aspirated and confirmed by surgical pathology after birth at the authors' center. The teratoma in this case was characterized by a large single cystic mass with clear borders in the anterosuperior mediastinum, which grew rapidly and was closely related to the thymus. The infant was healthy at birth, and the tumor was surgically removed the age of 1 year. The postoperative course was uneventful, and the patient was in good health 6 years postoperatively. This case and literature review suggests that ultrasound examination can accurately diagnose fetal mediastinal teratomas, which is beneficial to provide an accurate basis for fetal prenatal intervention and treatment. Additionally, an important ultrasound feature of a fetal unicystic mediastinal teratoma is a saddle‐shaped mass with clear boundaries, which provided an accurate reference for the diagnosis of a fetal cystic mediastinal teratoma by prenatal ultrasonography.

Mature Triphyllic Cystic Teratoma of the Posterior Mediastinum in a Fetus: A Case Report and Literature Review

“…An appropriate differential diagnosis of cystic congenital thoracic lesions can be extremely challenging. Bronchogenic cysts, CCAMs of the lungs, diaphragmatic hernias, bronchopulmonary sequestrations, or thymic cysts must be considered first [ 8 ].…”

“…The most frequent extragonadal site in infants is the sacrococcygeal area (40%), followed by cervical and retroperitoneal distributions. That said, several other locations, such as intracranial/cerebral [ 7 ], mediastinal [ 5 , 8 , 9 ], gonadal, pharyngeal, hepatic, cardiac, pleural, and subcutaneous, have been reported as less common.…”

“…Mediastinal teratomas are among the least frequent, with reported percentages ranging from 2.6 to 4 in the literature [ 5 , 8 ].…”

“…Diagnosis is usually made during routine pregnancy checkups by ultrasonography, and differential diagnosis with other mediastinal masses is crucial, such as bronchogenic cysts, congenital cystic adenomatoid malformations of the lungs, diaphragmatic hernias, bronchopulmonary sequestrations, or thymic cysts [ 5 , 8 , 9 ].…”

“…To this day, while in the literature several reports of fetal anterior mediastinal teratomas can be found [ 5 , 8 , 9 ], there are only few reports of posterior mediastinal teratomas, none of which were diagnosed in a fetus or prenatally [ 11 , 12 , 13 ].…”