A 65 year old man presents with recurrent pleural effusion.
Here is the initial chest radiograph:
The PA chest radiograph shows something more insidious than the typical pleural effusion in the right chest. The opacity tracking along the lateral right pleural surface and slightly nodular contour raise suspicion for loculated pleural fluid and/or thickening.
The patient underwent a contrast-enhanced CT exam, and coronal images are shown below:
The CT shows extensive right-sided pleural thickening along with a moderate-sized loculated pleural effusion.
The patient underwent FDG PET/CT evaluation, with representative images shown below:
PET/CT images show diffuse metabolically active right pleural thickening, with chest wall invasion in the posterior right thorax.
This is a patient with pleural mesothelioma. This aggressive primary pleural malignancy is associated with prior asbestos exposure and an approximate 30-year latency period from exposure to presentation. There are several histologic subtypes: Epithelioid (better prognosis), Sarcomatoid, and Mixed.
Mesothelioma is often intensely metabolically avid, and FDG PET/CT is a helpful modality in disease staging. A critical decision point is identifying unresectable disease: T4 (chest wall invasion at >1 site, adjacent organ involvement), N3 (supraclavicular or contralateral mediastinal lymph node involvement), or M1 (distant metastases).
A pitfall to be aware of in PET/CT interpretation is prior talc pleurodesis. This may remain metabolically active for years after intervention, but can be distinguished from malignancy by linear hyperdensity on CT images.
Kruse M, et al. AJR 2013;201:W215–W226.