Huy T. Duong

Sellar Masses that Present with Severe Hyponatremia.

OBJECTIVE Hyponatremia is a known but underrecognized presentation of sellar lesions. Herein, we present a series of patients who presented with single or multiple episodes of hyponatremia. METHODS Over 5 years, patients undergoing endonasal surgery for a de novo sellar mass with hyponatremia as an initial presentation were included. Pathology, sodium levels, pituitary hormonal status, and treatment course were documented. RESULTS Of 282 patients, 16 (5.7%) (9 males, 7 females, age 32 to 84 years) presented with severe hyponatremia, with a mean serum sodium level of 115 ± 6 mmol/L (range, 101 to 125 mmol/L), and 3 patients had 2 or more episodes. Severe hyponatremia was a presenting sign in 0, 4.1, 14.3, and 37.5% of patients with craniopharyngiomas (n = 10), pituitary adenomas (n = 243), Rathkes cleft cysts (RCCs) (n = 21), and sellar arachnoid cysts (n = 8), respectively (P<.01). Half of the patients presenting with hyponatremia, including 6 of 10 patients with adenomas and 2 of 3 patients with RCCs, had pituitary apoplexy or cyst rupture. All patients had anterior pituitary gland dysfunction, including 81% with hypoadrenalism and 69% with hypothyroidism. Following surgery, hormonal status was unchanged or improved in 15 patients (median follow-up, 14 months). No patient had tumor/cyst recurrence or recurrent hyponatremia. CONCLUSION Severe hyponatremia was a presenting sign in 5.7% of patients with sellar pathology, most frequently in patients with arachnoid cysts, RCCs, and pituitary apoplexy. Patients with new-onset severe hyponatremia and no obvious pharmacologic or systemic cause should undergo pituitary hormonal evaluation and brain imaging. Surgical resection and correction of hormonal deficiencies are associated with resolution of recurrent hyponatremic episodes.

Chemotherapy-Induced Regression of an Adrenocorticotropin-Secreting Pituitary Carcinoma Accompanied by Secondary Adrenal Insufficiency

Purpose. Adrenocorticotropin- (ACTH-) secreting pituitary carcinomas are rare and require multimodality treatment. The aim of this study was to report the response to various therapies and discuss the potential development of secondary adrenal insufficiency with cytotoxic chemotherapy. Methods. This report describes a man with a large silent corticotroph adenoma progressing to endogenous hypercortisolism and metastatic ACTH-secreting pituitary carcinoma over a period of 14 years. Results. Seven years after initial presentation, progressive tumor enlargement associated with the development of hypercortisolism mandated multiple pituitary tumor debulking procedures and radiotherapy. Testing of the Ki-67 proliferation index was markedly high and he developed a hepatic metastasis. Combination therapy with cisplatin and etoposide resulted in a substantial reduction in tumor size, near-complete regression of his liver metastasis, and dramatic decrease in ACTH secretion. This unexpectedly resulted in symptomatic secondary adrenal insufficiency. Conclusions. This is the first reported case of secondary adrenal insufficiency after use of cytotoxic chemotherapy for metastatic ACTH-secreting pituitary carcinoma. High proliferative indices may be predictive of dramatic responses to chemotherapy. Given the potential for such responses, the development of secondary adrenal insufficiency may occur and patients should be monitored accordingly.

Preservation of Bilateral Nasoseptal Flap Vascular Pedicles: Rescue Flap Modification for Endonasal Skull Base Surgery

Objectives: The nasoseptal flap (NSF) has significantly reduced the incidence of postoperative cerebrospinal fluid (CSF) leaks in endoscopic skull base surgery. In the traditional endonasal approach, the NSF vascular pedicle is frequently sacrificed during the sphenoidotomy, thus eliminating the flap as a reconstruction option should a large CSF leak be encountered. In addition, extensive mucosal removal may result in postoperative crusting, hyposmia, or anosmia. Methods: Introduce the concept and surgical technique of bilateral mucosal and septal olfactory strip (SOS)-preserving rescue flaps, ensuring availability of both vascular pedicles while also promoting rapid healing and reducing the risk of postoperative epistaxis and olfactory dysfunction. Retrospective analysis of patient records who underwent endoscopic tumor/cyst removal with bilateral nasoseptal rescue flaps from August 2011 until December 2012 (15 months). Results: In total, 95 (80%) of 118 patients (mean age 51 years; 78 pituitary adenomas, 7 RCC, 10 other pathologies), including 20 (21%) with prior surgery, underwent bilateral rescue flaps. Unencumbered visualization, mobility of the endoscope and instruments, and access to the sphenoid sinus/parasellar region was experienced in all cases. One patient underwent conversion to a formal NSF without complication. No patient had postoperative arterial epistaxis. Conclusions: This modification of the nasoseptal rescue flap technique is an effective bilateral mucosal preserving approach. In addition to maintaining both vascular pedicles, it likely reduces the risk of major postoperative epistaxis, preserves olfaction by maintaining the SOS, and promotes rapid mucosal healing while not hindering exposure or limiting instrument maneuverability.