PMC10046803_01
Pathology evaluation of a liver biopsy sample showed a poorly differentiated carcinoma, growing in nests or trabecular patterns without gland formation or keratinization and morphologically resembling large-cell neuroendocrine carcinoma. [(A); x400 H&E]. The tumor was positive for chromogranin (B), pan-keratin (C), and calcitonin (D).
fonc-13-1134151-g001.jpg
PMC10046803_01_fonc-13-1134151-g001.jpg
f1
Pathologic evaluation revealed a poorly differentiated carcinoma, growing in nests or trabecular patterns without gland formation or keratinization and morphologically resembling large-cell neuroendocrine carcinoma ( Figure 1A ). Immunohistochemistry (IHC) was positive for synaptophysin, chromogranin ( Figure 1B ), pankeratin ( Figure 1C ), calcitonin ( Figure 1D ), and CK7 with a high Ki-67 proliferative index of 80%.
Pretreatment images were obtained 3 weeks prior to the initiation of chemotherapy. The images in the second column were taken 1 month after the start of selpercatinib treatment (3 weeks after the first day of the second cycle of chemotherapy). CT images show shrinkage of lesions in the right upper lobe (A-D) and in the liver (E-H). Brain lesions responded to selpercatinib [(I-L), arrows] except for the development of tiny new brain lesions when the patient was on a low dose of selpercatinib 40 mg twice daily [(K), arrowhead], which have improved [(L), arrowhead] or remained stable with subsequent increases in dose of selpercatinib. At 7 months, the patient was receiving a dose of 120 mg of selpercatinib in the morning and 80 mg in the afternoon.
fonc-13-1134151-g002.jpg
PMC10046803_01_fonc-13-1134151-g002.jpg
f2
The patient achieved a partial response with shrinkage of the right upper lobe nodule ( Figures 2A-D ) and liver lesions ( Figures 2E-H ). Her brain lesions also responded to selpercatinib ( Figures 2I-L , arrows), except for the development of tiny new brain lesions when the patient was on a low dose of selpercatinib 40 mg BID ( Figure 2K , arrowhead), which have improved ( Figure 2L , arrowhead) or remained stable with subsequent increases in dose of selpercatinib.