today I am presenting another “Art of interpretation” case. I like them and think they have good teaching value.
Radiographs were taken for preoperative knee surgery in a 21-year-old man.
What is the most likely diagnosis?
1. Swyer-James-McLeod syndrome
2. Congenital hypoplasia of left lung
3. LUL collapse
4. None of the above
Click here to see the answer
Findings: PA radiograph shows a hyperlucent left lung with a small elevated hilum (A, white arrow). The trachea is deviated towards the left and the left main bronchus is curved upward (A, blue arrow). There is a small peak in the left hemidiaphragm (A, red arrow). And there is a triangular-shaped paraspinal opacity (A, circle), better seen in the cone down view (B, white arrow), with two linear metallic opacities inside (B, red arrows).
The lateral view (C) is unremarkable. Although the PA findings suggest loss of volume of the LUL, there are some negative findings: no anterior displacement of the left major fissure and no opacity indicative of LUL collapse.
Analysis of the findings
There are four obvious findings:
1. Hyperlucent left lung with small left hilum
2. Tracheal deviation to the left
3. Upward curving of left main bronchus
4. Juxtaphrenic peak (*)
All these findings are indicative of LUL volume loss with compensatory overinflation of the LLL.
There are two less obvious findings, which are diagnostic:
Paramediastinal opacity with surgical staples
No signs of LUL collapse in the lateral view
The first indicates previous surgery and the second excludes LUL collapse. Taken together, these findings lead to the obvious conclusion that the patient had undergone a previous lobectomy.
(*) The juxtaphrenic peak sign was described by my late friend Kenneth Kattan as an indirect sign of LUL collapse. Semin Roentgenol 1980; 15:187-193
LOSS OF VOLUME OF LUL + SURGICAL STAPLES = LUL LOBECTOMY
In the past, the patient had embryonal carcinoma of the testicle with a metastatic nodule in the LUL (A and B, arrows). He had undergone LUL lobectomy by video-assisted thoracic surgery one year before.
Final diagnosis: LUL lobectomy for metastasis of embryonal testicular carcinoma
I’m showing this case to emphasize the importance of identifying metal sutures in the chest radiograph. Nowadays, most surgical procedures are done by video thoracoscopy which doesn’t leave any telltale signs other than surgical staples. These are difficult to see because of their small size and because high kV “burns” metal density.
Staples are visible as a faint longitudinal ring chain somewhat denser than the surrounding tissues. It’s very important to be familiar with their radiographic appearance because they offer valuable information about previous surgery.
When staples are detected, our interpretation of associated findings may change, as occurred with the case presented.
To familiarize you with the radiological appearance of surgical staples, I’m showing three more cases.
88-year-o.ld man with dementia and moderate dyspnea. Chest radiographs show a nodule in the RUL (A and B, arrows). PA view shows post-surgical changes at the left 6th and 7th ribs and a hyperlucent left lung with a small hilum. There are surgical clips in the mediastinum (A and B, red circles). These findings suggest a previous LUL lobectomy and a second primary tumor. The patient’s records disclosed a LUL lobectomy for carcinoma twenty years earlier. The second primary tumor was confirmed by needle biopsy.
The radiographic findings are typical of “old” chest surgery.
PA radiograph of a 23-year-old woman with a nondescript LUL infiltrate (A, arrow). Close-up view reveals a longitudinal ring chain of staples within the infiltrate (B, arrows), pointing to a man-made opacity secondary to video thoracic surgery.
Diagnosis: changes after endoscopic LUL bullectomy for recurrent pneumothorax.
I saw this case three weeks ago and it is still unproven. A 44-year-old woman from another country came for a routine cardiac checkup. The PA chest radiograph shows a serpiginous opacity in the LLL (A, arrow) with a ring chain of staples in the periphery, better seen in the cone down view (B, arrows). On questioning, the patient mentioned previous endoscopic surgery for a nodule in the left lung two years ago. Enhanced CT shows a solid lesion with staples in the periphery (C, arrow).
As the patient could not provide previous medical records, we were unable to ensure that the changes were attributable to scar tissue. A follow-up CT has been scheduled.
Final words: Staples are difficult to reproduce on the computer screen, and I have done my best. I assure you that they are easily visible on a 14 by 17 reading console, provided that you see and recognize them 🙂
Follow Dr. Pepe’s teaching points:
1. Surgical staples are visible as a faint longitudinal ring chain.
2. They indicate previous surgery and help to interpret the chest findings under a new light.