The patient was subsequently hospitalized due to worsening acute onset dyspnea, despite showing a clinical response to the treatment. Interval CT imaging revealed progressive multifocal ground-glass opacities superimposed on a pre-existing peribronchovascular fibrosis. An exhaustive evaluation to identify a potential infectious cause was conducted, effectively excluding most differential diagnoses. While our case report details the possible causes for the patient’s dyspnea and associated radiographic findings that included radiation pneumonitis (RP), radiation recall pneumonitis (RRP), and drug-induced pneumonitis, we would like to additionally add the consideration of lymphangitic carcinomatosis. Despite prior PSMA PET scans failing to demonstrate PSMA-avid lesions in previously noted pulmonary nodules, key radiographic findings at the time of hospitalization that were also appreciated to present in LC include interlobular septal thickening and peribronchovascular thickening indicative of a "crazy paving" pattern.
Additional features potentially pointing towards LC, such as hilar and mediastinal lymphadenopathy, and pleural effusions, were also found. Thus, we would like to make the addendum to include lymphangitic carcinomatosis (LC) in the differential diagnosis due to its radiographic congruency with the observed imaging patterns, despite the absence of PSMA-avid lesions on prior PET scans. This addendum is prompted by the recognition that LC, as a manifestation of metastatic spread through the lymphatic system, may not always exhibit PSMA avidity, particularly in the context of heterogeneous tumor biology or prior extensive treatment. The inclusion of LC expands our diagnostic consideration to encompass the full spectrum of potential etiologies contributing to the patient's pulmonary manifestations.”
Written by: John S. Wang,1 Terence Wong,2 Kevin A. Wu,1 Trey C. Mullikin,3 Andrew Armstrong1,4,5
- Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA.
- Department of Radiology, Division of Nuclear Medicine and Radiotheranostics, Duke University, Durham, North Carolina, USA.
- Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina, USA.
- Duke Cancer Institute, Durham, North Carolina, USA.
- Center for Prostate & Urologic Cancers, Duke Cancer Institute, Durham, North Carolina, USA.