Retropharyngeal calcific tendinitis is not a rare disease and is probably underdiagnosed because symptoms are nonspecific, treating physicians are often unfamiliar with this entity, and it is a self-limiting pathology.

Postoperative CSF leak significantly increases the risk of meningitis. Most cases of meningitis after skull base operation are probably associated with lumbar drainage infection or from an obscure leak.

The objective of the study is to present a large case series of parapharyngeal space tumors (PPST) and the most comprehensive literature review of tumor histopathologic distribution. The study was designed as internal case series and full Pubmed/MEDLINE electronic database review in a tertiary academic medical center. Tumor histopathology and patient demographics were obtained from a comprehensive Pubmed/MEDLINE database review, as well from an internal case series of 117 patients referred to our center between 1993 and 2013. Main outcome and measures of the study were to define the age, gender, and histopathology of PPST within a large internal case series and among the current body of published literature, and to propose a diagnostic and treatment algorithm for these tumors. Our cohort included 117 cases, 58 females and 59 males, with benign tumors comprising 85 % (n = 99) and malignant tumors 15 % (n = 18). A systematic review of published literature from 1963 to the present revealed 37 case series, and when combined with our present series, yielded a total of 2160 cases. Benign tumors are most common (78.8 %), with tumors of salivary gland (44.4 %), neural (34.4 %), and vascular (2.64 %) origin representing the largest subtypes. Pleomorphic adenomas (30.9 %), paragangliomas (13.1 %), and schwannomas (12.3 %) comprised the majority of all cases. Due to their rarity, data regarding the histopathologic distribution of PPST is scarce. We provide one of the largest case series and the most comprehensive review of these tumors in the literature to date, and offer our algorithm for evaluation and treatment.

We evaluated the utility of a three-dimensional (3-D) endoscopic system for skull base surgery. We performed a retrospective case series in a tertiary care medical center. Thirty-six patients underwent skull base (nonpituitary) resections via 3-D endoscopic system. Fifteen patients (42%) were operated for excision of malignant tumors, 19 (53%) for excision of benign lesions, and 3 (8.3%) for skull base reconstruction. The tumors involved the cribriform plate (n ¼ 13), sphenoid sinus and planum (n ¼ 17), clivus (n ¼ 7), and sella (n ¼ 7). Complete tumor resection was achieved in 31 patients and subtotal resection in two. Five patients (14%) had postoperative complications. There was one case of meningitis, and there were no cases of cerebrospinal fluid leak. The surgeon's ability to recognize anatomic structures at the skull base was evaluated using the 3-D and two-dimensional systems. The 3-D technique was superior to the conventional technique for identification of the sella, carotid prominence, optic prominence, cribriform plate, sphenoid, and fovea ethmoidalis. The two systems were equal for detection of the turbinates, clivus, maxillary, ethmoids, and frontal sinuses. Endoscopic skull base surgery with stereoscopic viewing is feasible and safe. Further studies are required to evaluate the advantage of binocular vision in skull base surgery.KEYWORDS: Endoscopic approach, stereoscopic view, minimal invasive, skull base, three-dimensional, surgery Endoscopic endonasal surgery became the workhorse for treating inflammatory diseases and neoplasms involving the paranasal sinuses and skull base over the past decade. 1 Endoscopic surgery provides excellent access to the anterior skull base and to the sphenoethmoidal and paranasal cavities while minimizing morbidity. Intradural and extradural tumor resection can be performed endoscopically in a single procedure that also allows adequate reconstruction of the dura. 2 The technical reproducibility of the endoscopic approach has several advantages, but one of its major limitations is the lack of stereoscopic vision. A three-dimensional (3-D) image of the surgical field is essential for the perception of depth during microsurgery, and so the binocular view of the surgical field may be advantageous for the implementation of new endoscopic procedures and for popularization of this technique. 3 Several new 3-D endoscopic systems have been added to our armamentarium, but questions about their actual benefit led to their slow integration into practice. 4