Ventilation-perfusion imaging in sarcoidosis: potential for nonembolic segmental mismatch

Area of Science:

• Cardiology
• Pulmonology
• Radiology

Background:

• Pulmonary embolism is a common cause of chest pain in postpartum women, especially those on oral contraceptives.
• Ventilation-perfusion (V/Q) imaging is a standard diagnostic tool for pulmonary embolism, but can show mismatches in other conditions.
• Extrinsic compression of pulmonary arteries can mimic signs of embolism.

Observation:

• A postpartum woman on oral contraceptives presented with chest pain and was initially treated for pulmonary embolism based on V/Q scan findings.
• Angiography demonstrated extrinsic compression of the pulmonary artery, not an intraluminal clot.
• Gallium-67-citrate imaging revealed sarcoidosis with characteristic uptake in hilar nodes, lungs, and salivary glands.

Findings:

• The patient's chest pain and V/Q scan findings were attributed to extrinsic compression of the pulmonary artery by sarcoidosis.
• Sarcoidosis, a multisystem inflammatory disease, can affect various organs, including pulmonary and salivary glands.
• Oral contraceptive use in this case was a potential contributing factor to the initial misdiagnosis.

Implications:

• This case highlights the importance of considering extrinsic compression in the differential diagnosis of pulmonary embolism, especially in patients with atypical presentations.
• Accurate diagnosis through advanced imaging like angiography and gallium scintigraphy is crucial for appropriate management.
• Understanding the diverse manifestations of sarcoidosis is essential for clinicians managing patients with unexplained chest pain or respiratory symptoms.