Radiological Characteristics of Upper Abdominal Teratomas in Infants

A recent study set out to evaluate the radiological characteristics of upper abdominal teratomas, particularly in infants, with emphasis on vascular anatomical relationships.

The results of the study show that although upper abdominal teratomas in infants have typical radiological features, preoperative delineation of the major vascular anatomy is often imprecise.

In this retrospective study, the pathology database was searched to identify patients who had a confirmed diagnosis of abdominal or retroperitoneal teratoma over a 13-year period. Exclusion criteria included age >12 months at diagnosis, and/or extra-abdominal teratoma. Pathological, surgical, and radiological data were reviewed.

Imaging studies were re-evaluated independently by 3 different radiologists with specific reference to expected typical features of teratoma, anatomic location, and adjacent vascular anatomy.

The study has shown that the typical radiological features of teratoma are large, complex, and usually well-circumscribed masses with cystic components containing fat and areas of calcification.

Results of the Study
12 infants with a median age of 3 months were identified, of which 10 were girls. The median axial dimension of the teratoma mass was 11 cm. All masses were heterogeneous with solid and cystic components on ultrasound images. Calcification could be demonstrated on 50% of the ultrasound studies.

On CT scan, the correct diagnosis was suggested in 8 of 10 patients. Only 1 patient did not have calcification on CT. All but 2 patients had fat content on CT.

On review of CT imaging, the infrahepatic IVC was only positively identified in 2 patients. The distal IVC was only identified in 1 patient, and prominence of the azygos vein was demonstrated in 5 infants.

Deviation of the abdominal aorta was observed in 3 patients.

All lesions were shown to have a retroperitoneal component.

When surgical findings were retrospectively correlated with CT imaging, the important vascular relationships were seen to be poorly identified on imaging.

Conclusions
The typical radiological features of teratoma are large, complex, and usually well-circumscribed masses with cystic components containing fat and areas of calcification. The distortion of vascular anatomy and its delineation on radiology studies is imprecise when correlated to surgical findings.

Reviewer’s Comments
The rarity of intra-abdominal teratomas in infants precludes a large study. The typical radiological features are well known, but the clear important message of this study of 12 infants is the inability to accurately describe the relationship to distorted vascular anatomy–something worth noting to surgeons when discussing this rare finding.

Author: Basil Hubbi, MD

Reference:
Hart J, Mazrani W, et al. Upper Abdominal Teratomas in Infants: Radiological Findings and Importance of the Vascular Anatomy. Pediatr Radiol; 2008; 38 (July): 750-755