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Vol.61 No.5 contents | Japanese/English |
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- Case Report -
A Case of Pulmonary Pleomorphic Carcinoma with an Epidermal Growth Factor Receptor Gene Exon 20 Insertion Mutation Treated with Osimertinib
Yuma Sato1, Yasutaka Kawai1, Arika Ichinohe1, Takayuki Kiuchi2, Yasuyuki Ikezawa11Department of Respiratory Medicine, 2Department of Pathology, Oji General Hospital, Japan
Background. The positivity rate of epidermal growth factor receptor (EGFR) gene mutations in pulmonary pleomorphic carcinoma (PPC) is approximately 15-20%. Most EGFR gene mutations in PPC are common mutations. Cases of EGFR exon 20 insertion mutation positivity are very rare. Case. A 62-year-old man was referred to our hospital because of hemoptysis related to a lung tumor. Computed tomography revealed a lung tumor shadow with a cavity in the left lower lobe. Thoracoscopic left lower lobectomy was performed, and a diagnosis of PPC pT3N0M0 Stage IIB was confirmed. The patient presented with low back pain and right femoral pain, bone metastasis of the first lumbar vertebra and right femoral trochanter, lung metastasis, left renal metastasis, and left cerebral metastasis, and a diagnosis of recurrence was made. A gene mutation search was performed on the surgical specimen, and a positive test for the EGFR exon 20 insertion mutation was obtained. After mild irradiation of the first lumbar vertebral metastasis and intramedullary nail placement for the right femoral metastasis, osimertinib (80 mg/day) was administered. One month after treatment, the lung metastasis was reduced, and osteolytic changes improved in the first lumbar vertebra. However, three months after treatment, the left renal and left cerebral metastases had increased. We therefore concluded that the disease had progressed. Conclusion. Although no long-term response was obtained, we encountered a rare case in which treatment with osimertinib was administered in the early perioperative period for EGFR exon 20 insertion mutation-positive PPC, and a certain degree of disease control was achieved.
key words: Pulmonary pleomorphic carcinoma, EGFR exon 20 insertion mutation, Osimertinib
Received: December 17, 2020
Accepted: May 27, 2021
JJLC 61 (5): 412-416, 2021
