A 44-year-old man with a 10 pack-year history has exertional dyspnoea. HRCT shows striking basal-predominant panacinar emphysema with large basal bullae and relative apical sparing. He had abnormal liver enzymes last year attributed to mild chronic hepatitis. Which additional finding would be expected?

• A Upper-lobe centriacinar lucencies matching his modest smoking exposure
• B Eggshell hilar calcification on plain radiograph
• C Multiple thin-walled round cysts scattered uniformly through all lung zones in a nonsmoking woman
• D Serum alpha-1 antitrypsin level below the putative protective threshold of approximately 35 to 57 mg/dL with a PiZZ phenotype ✓

Explanation

Basal panacinar emphysema in a relatively young patient, especially with liver involvement, points to homozygous PiZZ alpha-1 antitrypsin deficiency, where serum levels fall well below the protective threshold of roughly 11 micromolar (about 35 to 57 mg/dL depending on assay). Eggshell calcification indicates silicosis, uniform thin-walled cysts suggest lymphangioleiomyomatosis, and ordinary smoking produces upper-lobe centriacinar emphysema disproportionate to his small smoking burden here.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.