So this comes down to 2 causes of cystic lung disease: LAM (lymphangioleimyomatosis) and the pulmonary manifestations of LCH (Langerhan’s cell Histiocytosis).

LAM:

- thin walled cysts of varying size surrounded by normal lung parenchyma

- dilated thoracic duct (chylothorax)

- hyperinflation

PLCH:

- nodules and/or cysts that are irregular in shape with thick walls

- sparring of lower lungs and costophrenic angles

- younger patient (20-40) with history of smoking

Answer: pulmonary LCH

LCH: https://radiopaedia.org/articles/pulmonary-langerhans-cell-histiocytosis

LAM: https://radiopaedia.org/articles/lymphangioleiomyomatosis-1

nice comparison: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3841705/