Treatment of transient prosopagnosia with a tyrosine kinase inhibitor in a case of brain metastasis from EGFR-mutated lung adenocarcinoma

BACKGROUND: Prosopagnosia is a rare form of apraxia, in which a person has normal memory and vision, but has impaired cognition of human faces that are manifested through symptoms such as not being able to recognize the face of a familiar person, one has known or not being able to remember the face of a person. Here, we report the case of a patient with transient prosopagnosia associated with brain metastasis from epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma who was treated with tyrosine kinase inhibitors (TKIs). CASE DESCRIPTION: A 52-year-old right-handed man with lung adenocarcinoma was introduced to our department because brain metastasis. On admission, he complained that he could not recognize his wife’s face, but he could recall her face based on her voice. MRI revealed a right temporo-occipital enhancing lesion with perifocal edema and dissemination that were indicative of brain metastasis from lung adenocarcinoma. Two weeks after open biopsy, he was started on TKI therapy with osimertinib at a dosage of 80 mg/day. An MRI scan taken 1 month later revealed shrinkage of the metastasis. In addition, he had recovered from transient prosopagnosia and returned to normal life. CONCLUSION: In this study, the TKI osimertinib was administered to a patient with brain metastasis of EGFR-mutated lung adenocarcinoma who presented with prosopagnosia, and the patient’s lesion shrunk and his symptoms were reversed with this treatment.