PMC8464369_01
Spontaneous regression of metastases after the discontinuation of chemotherapy. Plain CT scans in cross-sectional views of lung metastases and retroperitoneal lymph node (RPLN) metastases at 1 month after chemotherapy discontinuation (A and B). Plain CT of lung metastases (C) and PET-CT of RPLN metastases (D) at 7 months after chemotherapy discontinuation. Both lung and RPLN metastases spontaneously regressed without further treatment. During this time, the patient's hCG level decreased from 84,920 to 1402 IU/L.
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As shown in Figure 1, between January 2020 and June 2020, CT images revealed that both lung and RPLN metastases spontaneously regressed, and the hCG level decreased from 84,920 to 1402 IU/L.
Clinical course of treatment with pembrolizumab. Since the patient's hCG level started to re-increase after spontaneous regression continued for 8 months, immunotherapy with pembrolizumab was started. The hCG level decreased from 6500 to <1.0 IU/L after two doses of pembrolizumab. PET-CT 40 days after the start of treatment showed shrinkage of RPLN metastases with diminished metabolism.
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As shown in Figure 2, his hCG level continuously increased. Immunotherapy with pembrolizumab was then initiated, and as shown in Figure 2, the hCG level decreased from 6500 IU/L to <1.0 IU/L after only two doses of pembrolizumab.
Pathological section of RPLN metastasis biopsy. The biopsy specimen showed the infiltration of mixed germ cell cancer. Immunohistochemistry revealed strong positive staining for PD-L1. (A) Hematoxylin and eosin staining. (B) VENTANA (SP-142) immunohistochemistry assay, magnification: 200x.
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