Fig. 3

Gross and microscopic examination of the resected specimens. a Gross examination after fixation of the middle lobe mass had a grayish brown cut-surface and significant cystic lacunar structure. b Tumor parenchyma displayed perivascular haemangiopericytoma-like and solid sheets structure around sinusoidal blood vessels. c Periodic Acid-Schiff staining indicated abundant clear intracellular glycogen. d The small nodule of the left lower lobe was invasive lung adenocarcinoma presenting as acinar and solid subtype. b, c and d, original magnification × 400)