Safety of percutaneous ultrasound-guided fine-needle aspiration of adrenal lesions in dogs: Perception of the procedure by radiologists and presentation of 50 cases

Prediction of vascular invasion using a 7-point scale computed tomography grading system in adrenal tumors in dogs

BACKGROUND

Previous studies evaluating the accuracy of computed tomography (CT) in detecting caudal vena cava (CVC) invasion by adrenal tumors (AT) used a binary system and did not evaluate for other vessels.

OBJECTIVE

Test a 7-point scale CT grading system for accuracy in predicting vascular invasion and for repeatability among radiologists. Build a decision tree based on CT criteria to predict tumor type.

METHODS

Retrospective observational cross-sectional case study. Abdominal CT studies were analyzed by 3 radiologists using a 7-point CT grading scale for vascular invasion and by 1 radiologist for CT features of AT.

ANIMALS

Dogs with AT that underwent adrenalectomy and had pre- and postcontrast CT.

RESULTS

Ninety-one dogs; 45 adrenocortical carcinomas (50%), 36 pheochromocytomas (40%), 9 adrenocortical adenomas (10%) and 1 unknown tumor. Carcinoma and pheochromocytoma differed in pre- and postcontrast attenuation, contralateral adrenal size, tumor thrombus short- and long-axis, and tumor and thrombus mineralization. A decision tree was built based on these differences. Adenoma and malignant tumors differed in contour irregularity. Probability of vascular invasion was dependent on CT grading scale, and a large equivocal zone existed between 3 and 6 scores, lowering CT accuracy to detect vascular invasion. Radiologists' agreement for detecting abnormalities (evaluated by chance-corrected weighted kappa statistics) was excellent for CVC and good to moderate for other vessels. The quality of postcontrast CT study had a negative impact on radiologists' performance and agreement.

CONCLUSIONS AND CLINICAL IMPORTANCE

Features of CT may help radiologists predict AT type and provide probabilistic information on vascular invasion.

Safety of percutaneous ultrasound-guided fine-needle aspiration of adrenal lesions in dogs: Perception of the procedure by radiologists and presentation of 50 cases

Background

Percutaneous ultrasound (US)‐guided fine‐needle aspiration (FNA) of adrenal gland lesions is controversial in veterinary medicine.

Objective

To evaluate the frequency and radiologists' perception of the risk of the procedure as well as determining the incidence of complications.

Methods

Retrospective study. A first survey was submitted by e‐mail to all board‐certified radiologists of the American College of Veterinary Radiology (ACVR) and European College of Veterinary Diagnostic Imaging (ECVDI). A second survey was sent to radiologists who declared having performed the procedure at least once in their career (observational cross‐sectional case study).

Results

The first survey was sent to 977 diplomates and answered by 138. Of 138 diplomates, 40 currently performed the procedure and 98 did not; 44 of the 98 gave the hypertensive crisis risk in pheochromocytoma as a reason. To the second survey, 12 of 65 responded positively; 50 dogs with 58 lesions were recruited, including 23 pheochromocytomas. Complications were reported in 4 of 50 dogs; 3 hemorrhages (1 mild and 1 moderate) and 1 death from acute respiratory distress syndrome (possibly related to laryngeal paralysis). No hypertensive crisis was reported. There was no relationship between the method of FNA/type of needle used and occurrence of complications. Based on the recollection of these 65 radiologists, who performed approximately 200 FNA of adrenal lesions, a death rate of approximately 1% was estimated.

Conclusions and Clinical Importance

Percutaneous US‐guided FNA of adrenal lesions can be considered a minimally risky procedure, despite the negative perception by radiologists.