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Russell R. Lonser

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Steven M. Sorscher

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Satoru Shimizu

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Marc R. Mayberg

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Russell R. Lonser, Ronald R. Buggage, and Robert J. Weil

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Gautam U. Mehta, Russell R. Lonser, and Edward H. Oldfield

Although he never performed a pituitary operation for the disease, Harvey Cushing was the first to describe and treat patients with Cushing disease (CD). Other surgeons at the time were reluctant to operate on the pituitary due to the normal sella on skull radiographs in CD and the unclear etiology of the disorder. To better define and understand factors influencing the history of pituitary surgery for CD, the authors analyzed historical texts related to CD biology, diagnosis, and treatment. Cushing's monograph on basophilic pituitary adenomas and cortisol excess appeared in 1932. One year later in 1933, Alfred Pattison performed the first successful pituitary operation for CD by implanting radon seeds in the sella. Resection of a pituitary adenoma for CD was attempted 1 month later in 1933 by Howard Naffziger, resulting in only transient improvement that corresponded to the lack of tumor in the resected tissue. Soon thereafter, Susman in 1935 and Costello in 1936 described pituitary basophilic adenomas at autopsy in patients without premorbid endocrinopathy. They concluded that the adrenal gland was the cause of CD, which resulted in a 3-decade abandonment of pituitary surgery for CD. Jules Hardy in 1963 used the operating microscope to perform the first selective removal of an adrenocorticotropic hormone (ACTH)–secreting microadenoma, which established a pituitary cause and defined the modern treatment of CD. Subsequent reports by Hardy, Laws, and Wilson resulted in widespread acceptance of pituitary surgery for CD. Initial reluctance to operate on the pituitary for CD was multifaceted and included general uncertainty surrounding the etiology of Cushing syndrome as well as a lack of early surgical success, both due to the small size of ACTH-secreting adenomas. Selective removal of ACTH-secreting adenomas identified the source of CD and ended the delay in acceptance of pituitary surgery for CD.

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Russell R. Lonser, Lynnette Nieman, and Edward H. Oldfield

Cushing's disease (CD) is the result of excess secretion of adrenocorticotropic hormone (ACTH) by a benign monoclonal pituitary adenoma. The excessive secretion of ACTH stimulates secretion of cortisol by the adrenal glands, resulting in supraphysiological levels of circulating cortisol. The pathophysiological levels of cortisol are associated with hypertension, diabetes, obesity, and early death. Successful resection of the CD-associated ACTH-secreting pituitary adenoma is the treatment of choice and results in immediate biochemical remission with preservation of pituitary function. Accurate and early identification of CD is critical for effective surgical management and optimal prognosis. The authors review the current pathophysiological principles, diagnostic methods, and management of CD.

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Ahmed Mohyeldin, Russell R. Lonser, and J. Bradley Elder

OBJECT

The object of this study was to assess the feasibility, accuracy, and safety of real-time MRI-compatible frameless stereotactic brain biopsy.

METHODS

Clinical, imaging, and histological data in consecutive patients who underwent stereotactic brain biopsy using a frameless real-time MRI system were analyzed.

RESULTS

Five consecutive patients (4 males, 1 female) were included in this study. The mean age at biopsy was 45.8 years (range 29–60 years). Real-time MRI permitted concurrent display of the biopsy cannula trajectory and tip during placement at the target. The mean target depth of biopsied lesions was 71.3 mm (range 60.4–80.4 mm). Targeting accuracy analysis revealed a mean radial error of 1.3 ± 1.1 mm (mean ± standard deviation), mean depth error of 0.7 ± 0.3 mm, and a mean absolute tip error of 1.5 ± 1.1 mm. There was no correlation between target depth and absolute tip error (Pearson product-moment correlation coefficient, r = 0.22). All biopsy cannulae were placed at the target with a single penetration and resulted in a diagnostic specimen in all cases. Histopathological evaluation of biopsy samples revealed dysembryoplastic neuroepithelial tumor (1 case), breast carcinoma (1 case), and glioblastoma multiforme (3 cases).

CONCLUSIONS

The ability to place a biopsy cannula under real-time imaging guidance permits on-the-fly alterations in the cannula trajectory and/or tip placement. Real-time imaging during MRI-guided brain biopsy provides precise safe targeting of brain lesions.

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Joshua M. Ammerman, Russell R. Lonser, and Edward H. Oldfield

Object. To overcome the limitations associated with surgical approaches that have been described for accessing intraparenchymal lesions of the anteromedial region of the superior cerebellum, the authors used a posterior subtemporal transtentorial approach to remove tumors in this region. In this paper they describe the surgical technique that they used as well as the operative findings and clinical outcomes observed in patients who underwent resection of tumors in the anteromedial superior cerebellum.

Methods. The consecutive patients with anteromedial superior cerebellar tumors who underwent resection performed using the posterior subtemporal transtentorial approach at the National Institutes of Health were included in this study. Clinical, neuroimaging, and operative results were analyzed.

Three patients (two men and one woman) with anteromedial superior cerebellar tumors (two hemangioblastomas and one pilocytic astrocytoma) underwent resection via this approach. All the tumors were larger than 3 cm in diameter (range 3.1–3.5 cm). This approach provided excellent surgical access and permitted complete tumor resection in each case. The patients remained neurologically unchanged compared with preoperative baseline findings at the last follow-up examination (conducted at 4, 18, and 42 months postoperatively). One patient displayed a mild transient confusion immediately after surgery, but it resolved within 6 days.

Conclusions. The posterior subtemporal transtentorial approach provides excellent access to the anteromedial superior cerebellar region. This approach permits resection of large lesions in this location, while avoiding many of the limitations associated with other approaches to this site.

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Shailendra Kapoor