Background: Ameloblastoma is a benign locally invasive lesion that represents 1% of all oral tumors. Epidemiological characteristics are variable in the literature. The most common origin sites are mandible and maxilla. Rarely presents metastasis, but the skull base, lymph nodes, and the lung are described as metastatic sites. Low recurrence rates were reported by the authors when surgical treatment achieved complete resection. Case Description: A female patient, 19 years old presenting moderate headache associated with nausea, vomiting, left facial hypoesthesia, and low visual acuity. Resonance image showed a heterogeneous expansive solid formation in sphenoid bone and clivus with neoplastic aspect. Signs of dissemination due to contiguity and invasion of skull base structures, especially cavernous sinus and internal carotid artery, determining also compression of the brainstem. First, an endoscopic biopsy was performed with otorhinolaryngology service. The pathological study showed histological characteristics of ameloblastoma. After, the patient was submitted to endoscopic surgery for resection of tumor. Conclusion: Ameloblastoma is a rare tumor with benign behavior and slow growing. It arises from odontogenic epithelium and accounts 1% of all oral tumors. The mandible and maxilla are the most common sites of origin. Ameloblastoma with intracranial involvement is a rare presentation with few literature reviews. A long time illness course and multiple surgeries are characteristics present in the majority of cases described. Total resection surgery is the treatment of choice and endoscopic transnasal resection is a viable option.

Background: Primary central nervous system lymphoma (PCNSL) is an uncommon lesion and represent 4% of all central nervous system (CNS) cancers. There have been few reports of localized isolated lymphoma developing in the fourth ventricle, with only 8 previous cases described. We present a case of an immunocompetent patient with isolated fourth ventricle lymphoma who did not have diffusion-weighted imaging (DWI) restriction. Case Description: A 45-year-old man presented a history of headache, vomiting and weigh loss. Upon clinical examination, he presented bilateral papilledema, multidirectional nystagmus, and gait imbalance. Magnetic resonance imaging showed a solid tumor in fourth ventricle with 1.8 × 1.6 × 1.1 cm. The patient was submitted to a suboccipital telovelar approach. The pathological study showed a neoplasm composed of loose round cells. Immunohistochemistry showed positivity for CD-45 and CD-23. The diagnosis of primary CNS lymphoma of the fourth ventricle was certified. Patient was sent to complementary treatment with hematologist and radiotherapy and chemotherapy were started. Conclusion: PCNSL is a rare and aggressive pathology with high rates of mortality and recurrence. It requires a multidisciplinary team and multiple therapies to control the disease and deliver better quality of life and prognosis to the patient.

Background: Pituitary apoplexy (PA) is a syndromic condition described in 1950. The main symptoms are headache, visual impairment, ophthalmoplegia, and hypopituitarism. The relationship between stroke and PA is uncommon and two mechanisms are described: vascular compression and vasospasm. Case Report: A 65-old-year man presented with severe headache, vomiting, ophthalmoplegia, and somnolence. Radiological examinations showed an expansive sellar and suprasellar lesion with a heterogeneous signal, besides Diffusion-weighted imaging (DWI) restriction in the bifrontal area was present. The findings were compatible with PA and stroke. Conclusion: PA leading to cerebral infarction is a rare condition that presents high morbidity and mortality levels. There are two main mechanisms related: direct arterial compression and arterial vasospasm. The cases must be conducted as neuroendocrinological emergencies and surgical management is a key point to better the prognosis of patients.