Intrasellar chordoma associated with a primitive persistent trigeminal artery

Immunophenotypic features of dedifferentiated skull base chordoma: An insight into the intratumoural heterogeneity

Chordomas are rare and low-grade malignant solid tumours, despite their histologically benign appearance, that arise in the bone from embryonic notochordal vestiges of the axial skeleton, a mesoderm-derived structure that is involved in the process of neurulation and embryonic development. Chordomas occurring in the skull base tend to arise in the basiocciput along the clivus. Three major morphological variants have been described (classical, chondroid, and atypical/dedifferentiated). The pathogenesis and molecular mechanisms involved in chordoma development remain uncertain. From a pathological standpoint, the microenvironment of a chordoma is heterogeneous, showing a dual epithelial-mesenchymal differentiation. These tumours are characterised by slow modality of biologic growth, local recurrence, low incidence of metastasis rates, and cancer stem cell (CSC) phenotype. The main molecular findings are connected with brachyury immunoexpression and activation of the downstream Akt and mTOR signalling pathways. The differentiation between typical and atypical chordomas is relevant because the tumoural microenvironment and prognosis are partially different. This review provides an insight into the recent and relevant concepts and histochemical markers expressed in chordomas, with special emphasis on dedifferentiated chordomas and their prognostic implications.

Double pituitary adenomas associated with persistent trigeminal artery: a rare case report and the review of literature

Multiple pituitary adenomas are rare. We present a quite unique case of double pituitary adenomas associated with persistent trigeminal artery (PTA) treated by endoscopic surgery. To the best of our knowledge, this is the first report in the literature. A 64-year-old woman was referred to our hospital for suspicion of acromegaly. Preoperative magnetic resonance imaging revealed two separate intrasellar masses with intrasellar vascular structure. Right cerebral angiography showed medial-type PTA. The patient underwent endoscopic transsphenoidal surgery and both tumors were resected completely. Postoperative immunohistopathologic examination revealed two histologic types of adenoma: the first tumor was positive for growth hormone (GH), while the second was considered nonfunctioning. Postoperatively, the patient's serum levels of GH and insulin-like growth factor-1 returned to normal. We observed an extremely rare case of double pituitary adenomas associated with PTA. Preoperative neuroimaging and modern endoscopic surgery are valuable to confirm diagnosis of double pituitary adenomas and identify anatomical localization of PTA.

Persistent Trigeminal Artery in Endonasal Resection of Skull Base Tumors: A Systematic Review

Background Primitive persistent trigeminal artery (PTA) is an uncommon embryologic vascular communication between the carotid and basilar arteries, which can be intimately involved by skull base tumors (SBT). Owing to its rarity, skull base surgeons should familiarize themselves with the anatomical variations of PTA to avoid catastrophic complications. Objective To appraise and summarize the available evidence of PTA involved by SBTs while advocating a standardized algorithm for the surgical planning of these patients. Methods MEDLINE and PubMed databases were searched using keywords pertaining to PTA and SBTs. Demographics, clinical presentation, radiographic findings, outcomes, and adverse events were extracted and analyzed. Results A total of 13 cases between 1973 and 2015 were identified. The mean patient age at presentation was 43 years with predilections toward females and pituitary adenomas. Headaches and endocrine abnormalities were the most common symptoms. The tumors were more frequently associated with Salas medial-type PTA (70%) and Saltzman type-I PTA (31%) than seen in the general population in angiographic studies. We also present a new case of atypical meningioma with Saltzman type-1 PTA. Conclusion With endoscopic approaches to SBTs becoming more commonplace, surgeons may encounter this anatomical abnormality more frequently. It is important for both otolaryngologists and neurosurgeons to gain a complete understanding of the anatomical variations and neurointerventional capabilities for the successful endoscopic management of these situations. Level of Evidence: 4.