Severe intrapulmonary shunting associated with metastatic carcinoid

Area of Science:

• Oncology
• Pulmonology
• Gastroenterology

Background:

• Metastatic carcinoid tumors are neuroendocrine neoplasms that can metastasize to various organs, including the liver.
• Hepatopulmonary syndrome (HPS) is characterized by intrapulmonary vascular dilatations and hypoxemia in patients with liver disease.
• Carcinoid syndrome can manifest with various symptoms due to hormone release, but pulmonary complications are less commonly described.

Observation:

• A 37-year-old woman with a decade-long history of metastatic carcinoid presented with worsening dyspnea.
• Clinical evaluation revealed significant hypoxemia and evidence of intrapulmonary vasodilatation.
• The patient's liver function tests were within the normal range, ruling out significant hepatic dysfunction.

Findings:

• The patient exhibited a hepatopulmonary-like physiology, characterized by intrapulmonary shunting, despite having intact liver function.
• This presentation suggests that metastatic carcinoid disease itself, independent of liver compromise, can induce pulmonary vascular abnormalities.
• This represents the first documented instance of intrapulmonary shunting and hepatopulmonary-like physiology directly associated with metastatic carcinoid.

Implications:

• This case expands the understanding of potential pulmonary complications associated with metastatic carcinoid tumors.
• It suggests that oncologists and pulmonologists should consider evaluating for intrapulmonary shunting in patients with metastatic carcinoid presenting with dyspnea and hypoxemia.
• Further research is warranted to elucidate the mechanisms by which carcinoid tumors induce these pulmonary vascular changes.