We present an overview of the history, development, technological advancements, current application, and future trends of cranial endoscopy. Neuroendoscopy provides a safe and effective management modality for the treatment of a variety of intracranial disorders, either tumoral or non-tumoral, congenital, developmental, and degenerative, and its knowledge, indications, and limits are fundamental for the armamentarium of the modern neurosurgeon.

Although the histogenesis of meningeal hemangiopericytomas (HMP) remains controversial, both biological and clinical evidence seems to identify these neoplasms as a separate entity with respect to meningiomas. In order to assess the current prognosis of HMP we reviewed our personal experience limited to the last decade (1986-1995): during this period 7 patients (4M, 3F) were treated by surgery alone or surgery combined with postoperative radiotherapy. In spite of meticulous attempts at radical resection, the tumors recurred in all but two cases with a mean interval of 85 months, and a total of 18 operations were performed (2.57/patient; range 1-4). Massive intratumoral hemorrhage determined acute deterioration and required emergency surgery in two cases while in one patient diffuse visceral metastases were discovered at autopsy. Five patients are still alive at follow-up but only 2 of them are in good neurological conditions and without evidence of disease. These results are similar to those reported in other series. In view of our results we conclude that intracranial hemangiopericytomas still have a dismal prognosis. Advances in neuroimaging, neuroanesthesia, microneurosurgery and adjuvant therapy do not seem to have significantly affected the recurrence rate, quality of life and mortality.

The management of colloid cyst remains controversial, evaluation of the competing methods seems to be necessary. We report on our experience with colloid cysts in the last decade: ten were managed solely endoscopically, 10 were resected microsurgically (9 via a transcortical/transventricular, 1 via a transcallosal approach). The outcome in the endoscopic group was excellent in 9 cases and unsatisfying in 1 case (recurrence). In the microsurgical group we achieved a good outcome in 5 of 10 cases, a fair outcome in 4 cases and 1 lethal outcome (caused by pulmonary embolism). Complications in the endoscopic group: one intraoperative bleeding, 1 stitch granuloma, 1 mispuncture of the ventricle, and 1 meningitis. Complications in the microsurgical group: 1 subdural effusion, 1 flap infection, 1 mild hemiparesis, 1 transient impairment of consciousness and 1 pulmonary embolism. Mean operative time and length of hospitalization of the endoscopic group were clearly shorter than in the microsurgical group: 91 min versus 267 min time of surgery, 5.1 days versus 18.9 days of hospitalization. Complete resection was achieved in 8 of 10 cases of microsurgery, and in 3 of 10 cases in endoscopy. Endoscopic management results in lower costs and superior patients' comfort. The reduced number of total resections in the endoscopic group may lead to a higher recurrence rate in long-term follow-up, which might be a serious disadvantage of endoscopy. However, more experience in the endoscopic techniques may result in a higher rate of total resection of colloid cysts.

In our hands, this technique has proven minimally invasive, safe, and effective; although oncologically palliative it can be implemented with other therapeutic modalities. Our preliminary experience should stimulate the recruitment of larger groups of patients in order to define the role of neuroendoscopy in the multimodal treatment of craniopharyngiomas.

The recent increase in the detection of papillary thyroid carcinoma (PTC) has been influenced by the finding of incidental tumours. To this group, carcinomas measuring less than 1 cm (the so-called microcarcinomas) as well as those above 1 cm belong. Analyzing a case series from our own experience, this paper focuses on the current pre-operative diagnostic challenges that can lead to PTC incidental discovery. For this retrospective study, 287 patients with a PTC diagnosis were selected. For each, the following variables were analysed: sex, age, ultrasound (US) appearance, number of thyroid nodules, PTC size, PTC variants and presence of other associated pathology. Pre-operative fine needle aspiration (FNA) results were classified according to the five-tiered SIAPEC system. For 281 patients, the US-guided FNA results were available. Cytohistological correlation was evaluated in terms of FNA sensitivity and false negative rate. An incidental PTC was found in 45.2 % of patients. The majority of these were due to unsuccessful US detection of malignant nodules (103 cases); incorrect cytological diagnosis was responsible for the other 24 cases. The most powerful clinical confounding factors were: multinodular background versus single nodule presentations (p < 0.001) and histotype (follicular vs conventional variant, p < 0.05). Of course, tumour size remains a strongly influential feature on pre-operative diagnosis, with greater difficulties arising for carcinomas <5 mm. Moreover, FNA sensitivity was lower also in large PTCs (>2 cm) due to tumour heterogeneity. Although with limitations related to the tumour's intrinsic features and the thyroid background, US-guided FNA, especially if performed by a dedicated multidisciplinary team, is a powerful diagnostic tool for detecting malignant thyroid nodules. To the state of the art, we propose a practical clinical-pathological cut-off for this procedure, setting it at 5 mm.