Purpose or Case Report: Evaluate patient demographics, current imaging patterns, extent of disease, and tumor types in pediatric patients with mediastinal masses to assist with developing an imaging algorithm to streamline patient care.
Methods & Materials: Single institutional retrospective chart review of children with mediastinal masses between 2008 and 2018. Charts reviewed for pre-procedure symptoms, imaging characteristics, vascular and airway compression, pathologic results, and complications.
Results: 40 cases (33 initial, 7 residual/recurrent disease) of mediastinal masses in 37 patients were included for review. The median patient age at diagnosis was 15.03 years (IQR 11.67-17.27). In the initial diagnosis group, chest radiograph (n=29, 88%), and CT (n=31, 94%) were the predominant modalities used for prebiopsy evaluation. In the setting of recurrent disease, chest radiography x-ray (6), CT (5) and PET (4) were used to a identify residual/recurrent lesion. Physical signs or symptoms of mediastinal (vascular or airway) compression were present in 12 patients. On imaging, major airway compression was present in 22/33 patients with initial diagnosis and 1/7 patients with recurrent disease. Symptoms corresponded to a 67% PPV for vascular compression and an 83% PPV for airway compression. Major vascular compression was more common in primary disease (21/33) compared to recurrent/residual (2/7). Median interval between mass identification and biopsy was 1 day for the initial diagnosis group, and 4 days for the recurrent/residual disease group. Hodgkin’s (18/40, 45%) and Non-Hodgkin’s (12/40, 30%) lymphoma were the most common diagnoses. Other pathology included; Ewing sarcoma, aneurysmal bone cyst, Germ Cell Tumor, and neuroblastic tumor. In 4 cases a definitive result was not obtained from image guided biopsy. Bradycardic arrest occurred during a single procedure in a patient with central airway and SVC compression, that responded to CPR and change in patient position to alleviate airway/svc compression.
Conclusions: There is variation in imaging evaluation of initial and recurrent mediastinal masses in preparation for biopsy. Mediastinal compression is frequently present in both initial and recurrent disease, however, are inconsistently predicted by clinical symptoms. We propose an imaging algorithm that factors in radiation exposure, type of disease, patient age, signs and symptoms of vascular or airway compression to provide consistency and guidance for the pediatric and general radiologist.