PMC9834689_01
Response evaluation for the patient. (a) Baseline chest computed tomography (CT) showing a 14-mm nodule in right S6 (arrow). (b, c) contrast-enhanced CT of the chest (b) and abdomen (c) showing mediastinal lymph node enlargement (arrows) and left adrenal enlargement (arrow). (d-f) Thoracoabdominal CT after four courses of treatment revealed a partial response (48% reduction in the sum of diameters of target lesions). Images correspond to those in (a) through (c)
TCA-14-214-g001.jpg
PMC9834689_01_TCA-14-214-g001.jpg
tca14768-fig-0001
Contrast-enhanced magnetic resonance imaging (MRI) of the head showed a 45-mm mass in the left cerebellar hemisphere, and thoracoabdominal CT revealed a 14 mm nodule in the right lung segment 6, enlarged mediastinal and right subclavian lymph nodes, and an enlarged left adrenal gland (Figure 1a-c). After four courses of chemo-immunotherapy, RECIST evaluation revealed a partial response (Figure 1d-f, 48% reduction), and the patient was transitioned to atezolizumab monotherapy for consolidation.
Pathological findings for the surgical tumor specimen. (a) Hematoxylin-eosin staining showing diffuse proliferation of glycogen-rich cylindrical tumor cells with papillary glandular duct structures and a transition to a fuller growth with necrosis (inset). (b-h) Immunohistochemistry staining was negative for thyroid transcription factor-1 and positive for cytokeratin AE1/AE3, glypican-3, caudal-type homeobox-2, alpha-fetoprotein, Sal-like protein 4, and human epidermal growth factor receptor 2 (HER2), respectively. (i) Fluorescence in situ hybridization analysis of the surgical tumor specimen. Amplification of the HER2 gene (ERBB2, red) relative to a centromere control (green) was apparent in the tumor cells.
TCA-14-214-g003.jpg
PMC9834689_01_TCA-14-214-g003.jpg
tca14768-fig-0002
Pathological analysis of the surgical specimen of the cerebellar tumor revealed diffuse proliferation of glycogen-rich cylindrical tumor cells with papillary glandular duct structures and transition to a fuller growth with necrosis (Figure 2a). Immunohistochemistry (IHC) showed that the tumor was negative for thyroid transcription factor-1 (TTF-1) and positive for cytokeratin AE1/AE3, glypican-3, caudal-type homeobox-2 (CDX-2), AFP, and Sal-like protein 4 (SALL4) (Figure 2b-g). The IHC staining score for HER2 was 2+ (Figure 2h), and we further detected HER2 amplification in the tumor by fluorescence in situ hybridization (FISH, HER2/CEP17 = 2.8) (Figure 2i).