Spontaneous Tumor Regression of a Single Fiber Intracranial Tumor of the Elongated Brain: Case Description and Literature Review. Spontaneous regression of a monofibrous intracranial tumor originating from an elongated medulla oblongata. In addition, this case indicates that the LTCS in the fourth ventricle can sometimes spontaneously relapse without a known cause of this partial spontaneous regression. The head MRI showed a homogeneous lesion of the reinforcing mass located mainly in the fourth ventricle, extending to the spinal canal and the left occipital bulb, with a maximum diameter of 60 mm. CASH description: This study describes a very rare case of intracranial OCS in a 55-year-old woman who suffered from walking disorders and bilateral numbness of the upper limb 3 months before hospitalization. Surprisingly, this tumor showed spontaneous partial regression during planned surgery without therapy, including chemotherapy and radiotherapy. CONCLUSIONS: Although the localization of AFL in the fourth ventricle is rare, AFL should be considered as one of the differential diagnoses of the fourth ventricle tumor. It is interesting to note that there was no fixation in the posterior solid fossa and that the lesion was related only to the spinal part of the medulla oblongata. Providing information here, we do not diagnose, treat, relieve or prevent any disease or condition. Before performing any form of natural, integrative or conventional treatment, it is recommended to seek advice from a licensed physician. This patient has undergone an occipital middle craniotomy and tumor resection. Due to its rarity, some features of intracranial SIS still seem uncertain. Over 500 pages of information about alternatives and natural medicine.