Primary pulmonary arterial hypertension presenting as diffuse micronodules on CT

Area of Science:

• Cardiology
• Radiology
• Pulmonology

Background:

• Primary pulmonary arterial hypertension (PAH) is a rare, lethal condition.
• PAH is characterized by enlarged pulmonary arteries, vascular pruning, and cardiomegaly, typically with clear lung fields.
• Anorexigen use is an associated, though not fully understood, cause of PAH.

Observation:

• A patient with a history of fenfluramine and phentermine use presented with diffuse micronodules on computed tomography (CT).
• This radiographic presentation is unusual for primary pulmonary arterial hypertension.
• Lung biopsy was performed to investigate the cause of the micronodules.

Findings:

• Lung biopsy confirmed the diffuse micronodules were radiographic manifestations of extensive, diffuse plexogenic arterial lesions.
• Plexogenic arteriopathy is a known, albeit rare, complication associated with anorexigen use.
• This case demonstrates an atypical CT finding in anorexigen-related PAH.

Implications:

• This case highlights the importance of considering anorexigen exposure in patients with unexplained PAH.
• The findings suggest that diffuse micronodules on high-resolution CT scans can be a radiographic manifestation of anorexigen-related pulmonary arterial hypertension.
• Further research may be warranted to understand the spectrum of radiographic presentations in drug-induced PAH.