Small Cell Cancer of the Genitourinary Tract: A Case Report and Review of the Literature

An online tool for survival prediction of extrapulmonary small cell carcinoma with random forest

Purpose

Extrapulmonary small cell carcinoma (EPSCC) is rare, and its knowledge is mainly extrapolated from small cell lung carcinoma. Reliable survival prediction tools are lacking.

Methods

A total of 3,921 cases of EPSCC were collected from the Surveillance Epidemiology and End Results (SEER) database, which form the training and internal validation cohorts of the survival prediction model. The endpoint was an overall survival of 0.5-5 years. Internal validation performances of machine learning algorithms were compared, and the best model was selected. External validation (n = 68) was performed to evaluate the generalization ability of the selected model.

Results

Among machine learning algorithms, the random forest model performs best on internal validation, whose area under the curve (AUC) is 0.736-0.800. The net benefit is higher than the TNM classification in decision curve analysis. The AUC of this model on the external validation cohort is 0.739-0.811. This model was then deployed online as a free, publicly available prediction tool of EPSCC (http://42.192.80.13:4399/).

Conclusion

This study provides an excellent online survival prediction tool for EPSCC with machine learning and large-scale data. Age, TNM stages, and surgery (including potential performance status information) are the most critical factors for the prediction model.

Lambert-Eaton Myasthenic Syndrome Associated With Extrapulmonary Small Cell Cancer Detected by 18F-FDG PET/CT

A 46-year-old woman suffering from lower extremity weakness, dysarthria, dysphagia, dyspnea, and dry mouth was suspected of having Lambert-Eaton myasthenic syndrome based on the characteristic electromyographic abnormalities of right ulnar nerve, which demonstrated reduced resting compound muscle action potential amplitude and greater than 100% incremental change in high-frequency repetitive nerve stimulation. An F-FDG PET/CT was performed to detect the underlying neoplasm and revealed a retroperitoneal soft tissue mass with high F-FDG avidity in the left iliac fossa. The patient's symptoms were prominently relieved after the tumor resection, and the histopathology indicated a small cell carcinoma.