Early Diagnosis of Rare Diaphragmatic Synovial Sarcoma in a Pediatric Patient With Epigastric Pain Using Point-of-Care Ultrasound.

Synovial cell sarcoma is a rare mesenchymal tumor that typically originates from the soft tissues of the extremities of young adults. Only 3 cases of primary diaphragmatic synovial cell sarcoma have been described in the literature: 2 in adult males and 1 in a 12-year-old pediatric patient. 1-3 When this tumor is found in the mediastinum or pericardial region, prognosis is historically poor because of the advanced disease stage at time of diagnosis. The surgical course and pathology have been described in this 12-year-old boy. 3 This is the first case, to our knowledge, of the use of cardiac point-of-care ultrasound in the early identification and diagnosis of a primary diaphragmatic synovial sarcoma in a pediatric patient.