The Quadrangular Space, Endonasal Access to the Meckel Cave: Technical Considerations and Clinical Series.

OBJECTIVE: An anteromedial corridor via an expanded endoscopic endonasal approach to the Meckel cave (MC) was described more than a decade ago. However, few clinical series or endoscopic endonasal technical contributions exist concerning this type of approach to this complex region. METHODS: We present a detailed description of the surgical technique for this approach reviewing the original technique and adding clarifying conceptual notions. We conducted a multicenter retrospective study selecting patients who underwent endonasal endoscopic surgery for lesions exclusively limited to the MC in the past 6 years. Intraoperative and postoperative complications were analyzed. The study of 10 cadaveric specimens provides additional information. RESULTS: We performed a fully endoscopic anteromedial corridor to the MC in 18 patients. The most prevalent pathologic finding was schwannoma of the V nerve in 4 patients. Sixth cranial nerve palsy (13 patients) and trigeminal dysfunction (10 patients) were the predominant preoperative clinical signs. There were no remarkable intraoperative complications. Corneal keratopathy caused by dry eye syndrome affected 3 patients and V2 residual neuralgia appeared postoperatively in 2 patients. Six patients recovered from sixth cranial nerve palsy, and 2 showed improvement in preoperatively referred facial pain. CONCLUSIONS: The front door to the MC via the endonasal anteromedial corridor could be a good option. Understanding of the anatomy and the concept of the quadrangular space is crucial to performing this technique safely, which has few complications in experienced hands. Recovery from sixth nerve palsy is possible with this approach. Corneal keratopathy in these patients is a potential complication.

Our experience in prolactinomas larger than 60mm.

INTRODUCTION: Giant prolactinomas (tumor size larger than 40mm) are a rare entity of benign nature. Prolactinomas larger than 60mm are usually underrepresented in published studies and their clinical presentation, outcomes and management might be different from smaller giant prolactinomas. PATIENTS AND METHODS: We retrospective collected data from patients with prolactinomas larger than 60mm in maximum diameter and prolactin (PRL) serum levels higher than 21,200µIU/mL in our series of prolactinomas (283). Data were collected from January 2012 to December 2017. We included three patients with prolactinomas larger than 60mm. RESULTS: At diagnosis, two patients presented neurological symptoms and one nasal protrusion. All patients received medical treatment with dopamine agonists. No surgical procedure was performed. Median prolactin levels at diagnosis was 108,180 [52,594-514,984]µIU/mL. Medical treatment achieved a marked reduction (>99%) in prolactin levels in all cases. Tumor size reduction (higher than 33%) was observed in all cases. In one patient cerebrospinal fluid (CSF) leak was observed after tumor shrinkage. CONCLUSIONS: Dopamine agonists appear to be an effective and safe first-line treatment in prolactinomas larger than 60mm even in life-threatening situations. More studies with a higher number of patients are necessary to obtain enough data to make major recommendations.

Surgical Outcome and Treatment of Thyrotropin-Secreting Pituitary Tumors in a Tertiary Referral Center.

OBJECTIVE: Thyrotropin (TSH)-secreting pituitary tumors are rare and typically present with hyperthyroidism. Here we report the diagnosis, treatment, and surgical outcomes in a series of patients with TSH-secreting pituitary tumors in a tertiary referral center. METHODS: Descriptive retrospective study that included all patients with TSH-secreting pituitary tumors who underwent transsphenoidal surgery in the endocrinology and nutrition unit of the Virgen del Rocío University Hospital (Seville, Spain) between 2004 and 2016. RESULTS: The mean age at diagnosis was 42.8 ± 17 years. The mean time from onset of symptoms to diagnosis was 13 ± 10 months. Four patients displayed symptoms indicating hyperthyroidism (1 suffered from tachycardia); 3 patients showed symptoms because of mass effect (visual impairment and headache) and 3 patients were diagnosed based on incidental findings after routine blood tests (high free thyroxine levels). Eight patients had macroadenomas, and 2 patients had microadenomas. Five patients underwent conventional pituitary surgery, and 5 patients underwent expanded endoscopic transsphenoidal surgery. Six patients achieved cure after surgery. The other patients received radiotherapy and/or treatment with somatostatin analogs. Analysis of somatostatin receptor (SSTR) expression by immunohistochemistry could be performed in 6 tumors. CONCLUSIONS: Our results confirm the clinical and hormonal heterogeneity caused by TSH-secreting pituitary adenomas. Surgery is considered the first choice of treatment for these tumors. We observed surgical cure rates similar to those reported in recent published series. SSTR2 and SSTR3 are highly expressed in TSH-secreting pituitary adenomas. Our results suggest that somatostatin analog treatment may be also helpful in the treatment of TSH-secreting pituitary adenomas.