Histological features of a micronodular pneumocyte hyperplasia (MPH)-like lesion and adenocarcinomas.

<p><b>(A)</b> The sectioned surface of LP4-T1 is shown. The arrows indicate the white nodule that corresponds to an MPH-like lesion. <b>(B)</b> Hematoxylin and eosin (HE) staining of the MPH-like lesion. The lesion borders on the interlobular septum (ILS), indicated by arrowheads. <b>(C)</b> Further magnification of the lesion. Plump pneumocytes have enlarged nuclei that lack overt atypia and mitosis. The alveolar septa are thickened with dense fibers. <b>(D)</b> Computed tomography of LP1 demonstrates multiple cysts and a ground-glass opacity lesion indicated by arrows. <b>(E)</b> HE staining of the papillary adenocarcinoma (LP1-T1). A star indicates the cyst infiltrated by cancer cells. Inset: Higher magnification of the lesion. <b>(F)</b> HE staining of the micropapillary adenocarcinoma (LP2-T1). Inset: Higher magnification of the lesion.</p

Summary of clinical information.

<p>Summary of clinical information.</p

Summary of histology, gene mutations and immunostaining.

<p>Summary of histology, gene mutations and immunostaining.</p

Expression of phospho-mTOR (p-mTOR), phospho-S6 (p-S6), and <i>FLCN</i> in BHD lung neoplasms.

<p><b> (A)-(C)</b> The micropapillary adenocarcinoma (MPAC) (A), adenocarcinoma <i>in situ</i> (AIS) (B), and micronodular pneumocyte hyperplasia (MPH)-like lesion (C) show positive immunostaining for p-mTOR (left) and p-S6 (right). Lower p-mTOR and p-S6 staining intensities are observed in the MPH-like lesion compared to the adenocarcinomas. <b>(D)-(F)</b> The MPAC (D), AIS (E), and MPH-like lesion (F) are diffusely immunostained for <i>FLCN</i>.</p

Sequence analysis of <i>FLCN</i>, <i>EGFR</i>, and <i>KRAS</i> in BHD lung neoplasms.

<p><b> (A)</b> Germline and somatic <i>FLCN</i> status in 3 representative cases with different mutation patterns are shown. Control normal sequences are shown on the left. Germline mutations are shown on the middle. The somatic status of <i>FLCN</i> in microdissected neoplasms are shown on the right. <b>(B)</b> The papillary adenocarcinoma (PAC) had a heterozygous missense mutation (L858R) in <i>EGFR</i> (indicated by an arrow). <b>(C)</b> The micropapillary adenocarcinoma (MPAC) had a heterozygous missense mutation (G12D) in <i>KRAS</i> (right, indicated by an arrow).</p