SHM Converge Scientific Abstract ePoster Gallery-Antemortem Diagnosis of Pulmonary Tumor Microembolism Secondary to Parotid Adenocarcinoma

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A 78-year-old man with stage IV parotid gland adenocarcinoma developed 3 weeks of progressive dyspnea and worsening hypoxia despite home oxygen, eventually requiring high-flow nasal cannula. He had been hospitalized one week earlier with an unrevealing workup and was discharged on oxygen.<br /><br />During the current hospitalization, CT pulmonary angiography showed multiple lung nodules but no pulmonary embolism or clear parenchymal lung disease. He had no evidence of volume overload or orthodeoxia, and did not improve with empiric diuretics or steroids. Echocardiography revealed a patent foramen ovale with a large right-to-left shunt, which likely contributed to hypoxemia. Right heart catheterization was performed to assess shunting and hypoxia, but he decompensated afterward and required intubation. Pulmonary artery catheter wedge aspirate cytology showed high-grade carcinoma, confirming pulmonary tumor microembolism from his parotid adenocarcinoma.<br /><br />The case highlights pulmonary tumor microembolism as a rare but important cause of dyspnea and hypoxia in patients with solid malignancies. It is especially described in cancers such as urothelial carcinoma and invasive ductal breast carcinoma, but can occur with other metastatic tumors as well. Diagnosis of macroembolism may be possible on CT angiography, while microembolism often requires lung biopsy or pulmonary wedge aspirate.<br /><br />The patient’s course emphasized the poor prognosis of this condition: respiratory symptoms developed about 14 months after the cancer diagnosis, and death occurred within about 1 month of symptom onset. He was ultimately palliatively extubated on hospital day 12. The report underscores the importance of considering tumor microembolism in cancer patients with unexplained progressive hypoxia, as diagnosis can clarify prognosis and guide supportive or cancer-directed care.

Asset Subtitle

Danielle Madsen

Meta Tag

Author List Anand Viswanathan, Cindy Fang, Danielle Madsen, Jason N N. Chen

Category Clinical Vignettes

Concept Pulmonary Tumor Microembolism

Concept Dyspnea

Concept Hypoxia

Concept Solid Malignancy

Concept Macroembolism

Distinguished Non-Finalist

Presenter Organization NYU Grossman School of Medicine

Presenting Author Danielle Madsen

Track Adult

Keywords

pulmonary tumor microembolism

hypoxia

dyspnea

parotid adenocarcinoma

right-to-left shunt

patent foramen ovale

high-flow nasal cannula

CT pulmonary angiography

pulmonary wedge aspirate cytology

metastatic solid malignancy

Pulmonary Tumor Microembolism

Dyspnea

Hypoxia

Solid Malignancy

Macroembolism