[A case of cT0N2M0 small cell lung cancer with Lambert-Eaton myasthenic syndrome].
We encountered a very rare case of cT0N2M0 small cell lung cancer (SCLC) with Lambert-Eaton myasthenic syndrome (LEMS). A 69-year-old man with a complaint of muscle weakness was admitted to our hospital. Although his chest radiograph on admission showed no abnormal findings, CT scanning detected a mediastinal lymphadenopathy. Also, 2-[18F]-2-fluorodeoxy-D-glucose position emission tomography (FDG-PET) revealed increased accumulation in the same portion in the mediastinum. A diagnosis of LEMS was made from the distinctive electromyogram (EMG) findings (waning and waxing phenomenon in response to low-and high-frequency repetitive stimulation, respectively) in combination with the increased serum level of a P/Q-type anti-voltage-gated calcium channel (VGCC) antibody. Subsequent histopathological diagnosis by mediastinoscopic resection of a paraaortic lymph node was small cell carcinoma. No distant metastasis was detected by MRI of the brain, abdominal CT scan or an FDG-PET. Eight courses of chemotherapy (carboplatin + etoposide) with radiotherapy of the mediastinum (for a total dose of 45 Gy) was performed. A decreased serum level of P/Q-type anti-VGCC antibody titers followed by marked improvement of neurological dysfunction (muscle weakness, gait disturbance and scanning speech) and of an EMG finding (a loss of waning phenomenon) was observed. A close relationship between reduction of the antibody titers and improvement of neurological symptoms after the therapy was noticed. It was suggested that monitoring the level of a P/Q-type anti-VGCC antibody titer in the serum is important for evaluating the efficacy of chemotherapy for LEMS associated with SCLC.
Tsukiji
Jun
J
Kaneko
Takeshi
T
Saito
Haruhiro
H
Kobayashi
Masayoshi
M
Kakemizu
Nobumasa
N
Komatsu
Shigeru
S
Nishiyama
Harumi
H
Amano
Hiroko
H
Miura
Kenji
K
Satoh
Takashi
T
Shinohara
Takeshi
T
Mishima
Wataru
W
Yamakawa
Yasushi
Y
Nishihira
Ryuuichi
R
Miyashita
Akira
A
Noda
Kazumasa
K
Ishigatsubo
Yoshiaki
Y
Matsuse
Takeshi
T
D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001323:Autoantibodies / Q000032:analysis; D015220:Calcium Channels / Q000276:immunology; D016190:Carboplatin / Q000008:administration & dosage; D018288:Carcinoma, Small Cell / Q000150:complications* / Q000188:drug therapy / Q000532:radiotherapy; D004576:Electromyography; D005047:Etoposide / Q000008:administration & dosage; D006801:Humans; D015624:Lambert-Eaton Myasthenic Syndrome / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D008175:Lung Neoplasms / Q000150:complications* / Q000188:drug therapy / Q000532:radiotherapy; D008297:Male
D001323:Autoantibodies; D015220:Calcium Channels; D005047:Etoposide; D016190:Carboplatin