Spontaneous regression of small cell lung cancer associated with Lambert-Eaton Myasthenic Syndrome: Case report

• DOI: 10.1016/j.radcr.2023.08.059
• Publication Date: 2023-09-02T09:31:14Z
• Authors: Michimi Otani; Miki Nishimori; Hitomi Iwasa; Mamiko Iwamura; Takayasu Izumi; Kosuke Nakaji; Noriko Nitta; Kana Miyatake; Rika Yoshimatsu; Tomoaki Yamanishi; Tomohiro Matsumoto; Yasushi Osaki; Noriko Wada; Makoto Toi; Marino Yamamoto; Yu Nakatani; Tetsuya Kubota; Takuji Yamagami
• Keywords: Spontaneous regression; Medical physics. Medical radiology. Nuclear medicine; 03 medical and health sciences; 0302 clinical medicine; Small cell lung cancer; Lambert-Eaton myasthenic syndrome; R895-920; Case Report

Spontaneous regression (SR) of cancer is very rare, especially of small cell lung cancer (SCLC). Recently, an association of paraneoplastic neurological syndrome (PNS) has been reported as a cause of SR of cancer, and onconeural antibodies are a possible factor in the SR of cancer associated with PNS. We herein report the first case of SR of SCLC combined with anti-P/Q-type of voltage-gated calcium channel (VGCC) antibody-positive Lambert-Eaton myasthenic syndrome (LEMS), a subtype of PNS. This case report suggests that SCLC may be spontaneously reduced by an autoimmune response induced by VGCC antibodies associated with LEMS. Our finding may help elucidate the mechanisms that inhibit tumor growth and cause the regression of tumors.