Figure 1. Histopathology of adrenal gland metastasis
The biopsy specimen shows diffuse sheets of proliferating and highly
atypical, epithelioid cells with coagulation necrosis. The tumor cells
are relatively monotonous, with eosinophilic cytoplasm, vesicular
chromatin, 1–2 prominent nucleoli, and partial rhabdoid appearance.
Immunohistochemically, the tumor cells totally lacked SMARCA4 and
BRM (SMARCA2 ); were negative for AE1/3, Claudin4, desmin, MyoD1,
myogenin, CD99, CD56, and WT-1 proteins; and were weakly positive for
synaptophysin. Based on these results, the tumor was classified as a
thoracic SMARCA4 -deficient undifferentiated tumor. Driver gene
screening showed negative results for EGFR, ALK, ROS-1, KRAS, andBRAF. Immunohistochemical expression of programmed death-ligand 1
(PD-L1) was found to be 10–20%. Positron emission tomography-CT showed
a 3.4-cm primary tumor in the right upper lobe of the lung and
metastases to the mediastinal lymph nodes, multiple bones, and bilateral
adrenal glands (Figure 2). The tumor was thus staged as clinical stage
IVB (cT2aN2M1c).