Masaaki Usui

Simultaneous Combined Supra-Infrasellar Approach for Giant/Large Multilobulated Pituitary Adenomas

BACKGROUND Surgical treatment of few complex pituitary adenomas, mostly large/giant and multilobulated, still remains troublesome. We present our case series using a simultaneous combined supra-infrasellar approach for these tumors. METHODS We retrospectively reviewed our 29 consecutive patients who have undergone procedures using this approach since 2004. Preoperative characteristics and surgical outcomes were reviewed. RESULTS Total removal of the adenoma was achieved in 7 cases, subtotal removal in 21 cases, and partial removal in 1 case. Although surgical complications apart from pituitary insufficiency were noted in 12 patients, most were transient but permanent oculomotor nerve palsy and worsening of preoperative visual disturbance developed in 2 and 1 patient, respectively. CONCLUSIONS Because these complex adenomas are not only large and invasive but also tend to lack a well-defined tumor capsule, the combined approach was effective for the accurate and safe removal by manipulating from both sides. The present single-stage approach is a viable option for these few selected patients.

Preoperative identification of clearly separated double pituitary adenomas.

objective  Double pituitary adenomas are extremely rare. They can be divided into contiguous and clearly separated types. Most contiguous tumours are surgically removed as one tumour and the co‐existence of different adenoma types can be confirmed by histological methods. In contrast, detailed preoperative neuroimaging studies can suggest the co‐existence of separated multiple adenomas. In patients with multiple adenomas, surgical failure may result when one adenoma is missed during surgery. Among 600 surgical cases we encountered four patients with clearly separated double pituitary adenomas; all were highly suspect on preoperative MRI studies.

Pit‐1 gene expression in human pituitary adenomas using the reverse transcription polymerase chain reaction method

OBJECTIVE Previous studies of Pit‐1 expression in human pituitary tumours have produced conflicting results. We have studied expression of Pit‐1 mRNA in human pituitary adenomas, as well as in normal human and rat pituitaries, and results were compared with clinical, histological, and immunohistochemical features. In addition, expression of GH, PRL, and TSH‐β mRNA was also studied and compared with Pit‐1 gene expression.

Serum alpha-subunit levels in patients with pituitary adenomas.

OBJECTIVE We investigated preoperative and postoperative serum α‐subunit levels and the α‐subunit response to TRH in patients with various types of pituitary tumour and correlated the data with histological findings in order to clarify the significance of α‐subunit measurement in pituitary adenomas.

Sellar Neuroblastoma Mimicking Pituitary Adenoma

Abstract.Objective and importance: Primary intracranial neuroblastomas are rare. They generally arise in the supratentorial parenchyma or paraventricular region. Even more rare are primary sellar neuroblastomas. We present a neuroblastoma that arose in the sellar region and mimicked a non-functioning pituitary adenoma. Clinical presentation: This 33-year-old man presented with bitemporal hemianopsia. MRI showed a sellar mass with suprasellar extension mimicking a pituitary adenoma. Intervention: Because of tumor recurrence and dissemination to the cervical region, he underwent 6 operations and radiosurgery. Detailed histologic examination confirmed the diagnosis of neuroblastoma. Postoperative conventional radiotherapy was effective in reducing the size of the tumor. Conclusion: Neuroblastoma should be considered in the differential diagnosis of patients with sellar lesions.

Serial MR intensity changes of the posterior pituitary in patients with diabetes insipidus after transsphenoidal surgery for pituitary adenomas: report of two cases.

This is the first report describing magnetic resonance (MR) intensity changes of the posterior pituitary gland in the patients suffering from the classical “triphasic” diabetes insipidus (DI) after transsphenoidal surgery for pituitary adenomas. A 21-year-old female and a 54-year-old female were admitted to our hospital with the diagnosis of Cushings disease and acromegaly due to pituitary microadenomas, respectively. No evidence of DI was found, and T1-weighted MR images exhibited “bright spot” corresponding to the posterior pituitary in both cases. Both experienced the classical “triphasic” pattern of water metabolism disturbance after successful transsphenoidal resection of pituitary adenomas, that is, polyuria–oliguria–polyuria. The MR signal hyperintensity in posterior pituitary was detected during the first polyuric phase, but the hyperintensity disappeared during the second polyuric phase. In addition, “bright spot” was restored along with the recovery from DI in the chronic phase. These findings of serial MR images supported that the first DI phase of the classical triphasic course of water metabolism disturbance was caused by secretional dysfunction of stored vasopressin from the posterior gland, whereas the second DI phase was due to impairment in the functional integrity producing vasopressin—containing granules after depletion of vasopressin in the oliguric phase.