CASE 17302 Published on 27.05.2021

CSF hydrothorax diagnosed by radionuclide shuntography: a case report

Section

Paediatric radiology

Case Type

Clinical Cases

Authors

Kentaro Koike1,2,Takanobu Maekawa1, Mitsuru Kubota1, Akira Ishiguro2, Hideki Ogiwara3, Kenichi Usami3, Masayuki Kitamura4

1. Department of General Pediatrics and Interdisciplinary Medicine, National Center for Child Health Development, 2-10-1 Okura, Setagaya-ku, Tokyo, Japan

2. Center for Postgraduate Education and Training, National Center for Child Health Development, 2-10-1 Okura, Setagaya-ku, Tokyo, Japan

3. Division of Neurosurgery, National Center for Child Health Development, 2-10-1 Okura, Setagaya-ku, Tokyo, Japan

4. Department of Radiology, National Center for Child Health Development, 2-10-1 Okura, Setagaya-ku, Tokyo, Japan

Patient

9 years, male

Categories
Area of Interest Paediatric ; Imaging Technique CT, PET-CT, SPECT-CT
Clinical History

A 9-year-old boy with Angelman syndrome was admitted due to massive left pleural effusion. The patient had a surgical history of ventriculoperitoneal (VP) shunt placement and fundoplication with gastrostomy. A chest drainage tube was placed, and non-bacterial serous pleural effusion was continuously drained.

Imaging Findings

Initial decubitus chest X-ray showed compressed left lung with massive pleural effusion (Fig. 1) and computed tomography (CT) confirmed the diagnosis. As cerebrospinal fluid (CSF) hydrothorax was clinically suspected, contrast-enhanced VP shuntography was performed, resulting in neither intrathoracic migration of the VP shunt catheter nor visible contrast flow from the VP shunt toward the intrathoracic cavity (Fig. 2).

Accordingly, radionuclide shuntography using 99mTc-diethylenetriamine penta-acetic acid (DTPA) was performed to detect the CSF flow. The radionuclide CSF flow was observed to spread first to the subdiaphragmatic space, and then diffuse into the left intrathoracic cavity via a cystic cavity of the mediastinum (Fig. 3). Single-photon emission computed tomography (SPECT) showed a cystic cavity above the oesophagal hiatus (Fig. 4). CSF hydrothorax with pleuroperitoneal communication was diagnosed and neurosurgical shunt revision with ventriculoatrial (VA) shunt was performed. After revision, pleural effusion was markedly diminished.

Discussion

CSF hydrothorax is a rare VP shunt-related complication. Diagnosis of CSF hydrothorax without VP shunt catheter migration is challenging, although intrathoracic VP shunt catheter migration can relatively easily account for the CSF hydrothorax [1-3].

There are two diagnostic strategies for CSF hydrothorax, namely, cytological/ biochemical testing and radiological imaging. Testing measures, including white blood cell counts, levels of protein, lactase dehydrogenase and glucose, can sometimes help to differentiate the aetiology of the pleural effusion. However, these measurements do not have enough diagnostic power to distinguish the CSF from other serous pleural effusion. In contrast, CSF-specific protein β2 transferrin is a candidate for a diagnostic tool with high sensitivity and specificity. Unfortunately, however, β2 transferrin can be assessed in only a limited number of laboratories, and usually requires considerable time to determine. Therefore, its clinical utility is limited [4-5].

The candidates for radiological imaging studies are contrast-enhanced VP shuntography and radionuclide VP shuntography [6-9]. In our patient, contrast-enhanced VP shuntography with non-ionic water-soluble iodine-containing contrast agents did not exhibit evidence of CSF hydrothorax. We believe that it is difficult to reveal slow CSF flow and distribution in a large cavity by contrast-enhanced VP shuntography, though this method has an advantage in detecting an obstruction or a minor leakage of the VP shunt catheter. In contrast, as our patient showed, radionuclide shuntography with SPECT can visualize the dynamic distribution of CSF with whole-body imaging (Fig. 4). We believe that radionuclide VP shuntography is a reasonable modality when aberrant CSF communication is suspected.

The therapeutic approach for CSF hydrothorax with pleuroperitoneal communication is controversial. Aberrant CSF communication can be surgically repaired. Another choice is the replacement of the CSF outlet of the shunt catheter from the peritoneal cavity into the atrium. In our case, radionuclide shuntography revealed aberrant pleuroperitoneal communication, which may have developed by forming cystic structure of the fragile tissue around the fundoplication.

When a patient with a VP shunt has pleural effusion, pleuroperitoneal communication should be considered, and radionuclide shuntography can be a useful diagnostic modality.

Written informed consent for publication was obtained from the patient and his parents.

Differential Diagnosis List
CSF hydrothorax with pleuroperitoneal communication
CSF hydrothorax with intrathoracic VP shunt catheter migration
Parapneumonic effusion / Empyema
Chylothorax
Heart failure
Final Diagnosis
CSF hydrothorax with pleuroperitoneal communication
Case information
URL: https://www.eurorad.org/case/17302
DOI: 10.35100/eurorad/case.17302
ISSN: 1563-4086
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