Faculty Bibliography

PURPOSE/OBJECTIVE:The purpose of the study was to describe and present outcomes of the track embolization technique with absorbable hemostat gelatin powder during percutaneous computed tomography (CT)-guided lung biopsy and/or fiducial marker placement versus the standard of care (no track embolization) in an attempt to decrease rates of pneumothorax (PTX), chest tube placement, hemorrhage and/or complications, and average cost per patient. MATERIALS AND METHODS/METHODS:An institutional review board-approved, case-control, retrospective study was performed in which 125 consecutive patients who underwent track embolization were compared with 124 consecutive controls at one institution. For subjects in whom the track embolization technique was utilized, it was performed passively through a coaxial needle as it was removed. All procedures were performed by one of three attending interventional radiologists. For each group, medical records and procedure images were reviewed for PTX occurring postprocedure, PTX requiring chest tube placement, and occurrence of minor or major complication and/or hemorrhage. Comparison was made with published complication rates, and a cost-per-patient analysis was performed. Statistical analysis was performed utilizing Fisher's Exact Test. RESULTS:In track embolization cases versus controls, there were statistically significant reduction in PTX (8.8% vs. 21%; P=.007) and reduction in PTX requiring chest tube placement (4% vs. 8.1%; P=.195). This compares favorably to previously published rates of PTX and chest tube placement of 8%-64% and 1.6%-17%, respectively. None of the pneumothoraces occurring at time of needle placement increased in size with use of the track embolization technique. There were no major complications (including neurological sequela) in the track embolization group. In track embolization cases versus controls, there was a statistically significant reduction in both the rate of major hemorrhage (0% vs. 4%; P=.029) and average cost per patient ($262.40 vs. $352.07; P=.044). CONCLUSIONS:CT-guided percutaneous lung biopsy and/or fiducial marker placement were safer utilizing the track embolization technique during trocar removal. In addition, this technique was cost effective in the study population.

Aggregomas are rare localized masses of monoclonal nonamyloid immunoglobulin light-chain deposits. To date, there have been only a few reports of isolated aggregomas, with the majority detailing renal, lymph node and brain deposition. We present a rare case of paraspinal aggregoma in a 67-year-old female who presented with a complaint of cough and chest pain. Imaging demonstrated a left-sided paravertebral mass extending from T7-T10. Pathological analysis showed lamellar deposition of extracellular eosinophilic material with an associated lymphoplasmacytic nonamyloid infiltrate. To our knowledge, this is the first report of a paraspinal aggregoma. While exceedingly rare, this tumor can be included in the radiologic differential diagnosis of paravertebral soft tissue tumors in adults. The observation of our case adds to the limited understanding of the etiology, pathogenesis, natural history, and treatment of nonamyloid light-chain depositions.