J Korean Med Sci.  2004 Oct;19(5):753-755. 10.3346/jkms.2004.19.5.753.

A Case of Lambert-Eaton Myasthenic Syndrome Associated with Atypical Bronchopulmonary Carcinoid Tumor

• Lee JH
• Shin JH
• Kim DS
• Jung DS
• Park KH
• Lee MK
• Kim JY

• KMID: 1733522
• DOI: http://doi.org/10.3346/jkms.2004.19.5.753

Abstract

The Lambert-Eaton myasthenic syndrome (LEMS) is typically recognized as a paraneoplastic syndrome associated with a small cell lung carcinoma (SCLC), whereas LEMS with other neuroendocrine lung tumors, including carcinoids or large cell lung carcinoma, are highly unusual. Here, we report a rare case of LEMS with atypical bronchopulmonary carcinoid tumor: A 65-yr-old man presented with progressive leg weakness and a diagnosis of LEMS was made by serial repetitive nerve stimulation test. Chest CT revealed a lung nodule with enlargement of paratracheal lymph nodes, and surgically resected lesion showed pathological features of atypical carcinoid tumor. We concluded that LEMS could be associated with rare pulmonary neuroendocrine tumor other than SCLC, which necessitates pathologic confirmation followed by aggressive treatment for optimal management in these rare cases.

Keyword

Lambert-Eaton Myasthenic Syndrome; Carcinoid Tumor; Electrodiagnosis

MeSH Terms

Aged
Carcinoid Tumor/*complications/pathology/surgery
Electromyography
Humans
Lambert-Eaton Myasthenic Syndrome/*complications/diagnosis
Lung Neoplasms/*complications/pathology/surgery
Male

Figure

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  Fig. 1 Postexercise fascilitation and incremental response at high rate of stimuration in the abductor digiti minimi muscle. Note definite facilitation at high rate of stimulation is achieved by prolonged stimulation for 2 sec in second test. (A) Compound muscle action potential (CMAP) before exercise. (B) CMAP after 30 sec of exercise. (C) Response at 50/sec stimulation for 1 sec. (D) Response at 50/sec stimulation for 2 sec.

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  Fig. 2 (A) CT scan of the chest shows a 1.4 cm nodule (arrow) in the posterior segment of right upper lobe. (B) Atypical carcinoid tumor with mosaic patterns separated by thin fibrovascular stroma. The tumor cells have central round nuclei with abundant cytoplasm (H&E ×100).

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