Practical pituitary pathology: what does the pathologist need to know?

Clival invasion on multi-detector CT in 390 pituitary macroadenomas: correlation with sex, subtype and rates of operative complication and recurrence

BACKGROUND AND PURPOSE

Clival invasion, a rare but potentially significant complication of pituitary adenoma, is difficult to detect on MR imaging. Because CT is widely used in adjunct guidance of pituitary surgery and it has recently been suggested that preoperative CT may add useful diagnostic information in addition to pituitary MR imaging, we performed the first large cross-sectional imaging study to define the image attributes, clinical correlates, and prognostic implications of clival invasion on CT for pituitary adenoma surgical guidance.

MATERIALS AND METHODS

Preoperative CT images from 390 patients with histopathologically diagnosed pituitary macroadenoma were reviewed retrospectively and classified by the presence and degree of clival invasion. Tumor volume, tumor subtype, patient sex, operative complication, and recurrence rates were compared between groups.

RESULTS

After we corrected for multiple correlations, the most significant independent risk factor for clival invasion was female sex (OR=3.62, P=.014, multinomial logistic regression), followed by large tumor volume (OR=1.08, P<.001), and null-cell subtype (OR=5.47, P<.001). Larger tumor volume correlated with null-cell subtype (Mann-Whitney U test, P=.006), incidence of clival invasion (P<.001), and extent of clival invasion (P=.038). Clival invasion was associated with a significantly higher ratio of operative complications (15.63%, χ(2)=7.067, P=.008) and recurrence (57.14%, χ(2)=10.739, P=.001).

CONCLUSIONS

CT detection of clival invasion by pituitary macroadenoma is significantly more common in women, in patients with large tumors, and in patients with null-cell tumors, and it is associated with a higher rate of operative complications and recurrences. Attention to the presence of clival invasion on preoperative CT and prospective investigation of its prognostic significance are indicated. Attention to this finding on pituitary guidance CT is warranted.

Clinical Problem Solving: Monster on the Hook—Case Problems in Neurosurgery

BACKGROUND AND OBJECTIVE:

Nonfunctioning and functioning pituitary tumors can present in numerous ways. They may be difficult to diagnose correctly and, even with proper treatment, may lead to complications.

METHODS:

We present the case of a patient who presented with a large, invasive sellar mass and underwent both medical and surgical treatment for this lesion. The patient's course did not progress as was expected from his initial workup.

RESULTS:

The patient's history, physical examination, laboratory values, pathologic specimens, and radiologic findings are discussed. His management before, during, and after medical therapy and surgery is reviewed by pituitary experts from 2 different institutions. Aspects of diagnosis and management of sellar lesions are presented and reviewed in the literature.

CONCLUSION:

Neurosurgeons frequently treat patients with sellar lesions and should remember that despite modern laboratory, pathologic, and radiologic techniques, the diagnosis and treatment of these lesions is not always clear.

Prevalence of double pituitary adenomas in a surgical series: Clinical, histological and genetic features

BACKGROUND

The term double pituitary adenomas (DPA) is usually referred to those rare lesions showing two distinct cellular components. Genetic background may sustain the proliferation of more than one cell at the same time but no information is available on the presence of aip mutations in these patients.

AIM

We report the prevalence and the endocrinological, neuroradiological, histopathological and genetic features of DPA detected in a large surgical series. The contribution of pituitary transcription factor immunostains in DPA was also evaluated.

SUBJECTS AND METHODS

One-hundred-forty-four patients undergoing surgery for tumors of the sellar region were evaluated. Histopathology, immunohistochemistry and the mutational analysis for the entire coding region of the AIP and MEN1 genes were performed.

RESULTS

One-hundred-seventeen patients out of 144 had a pituitary adenoma. DPA was found in 3 (2.6%) out of 117 patients with pituitary adenoma. Immunohistochemistry and transcription factors analysis demonstrated two not yet described histotype associations in DPA. The coexistence of somatotroph-lactotroph and silent mammosomatotroph histotype in 1 case and the coexistence of sparsely granulated lactotroph and null cell adenomas in the remaining two cases were first identified. Sequencing data for the coding region of the aip and the menin gene resulted in wild type sequences in all patients with DPA.

CONCLUSIONS

The prevalence of DPA observed in our unselected surgical series is not negligible (2.6%). Furthermore, the evaluation of the treatment outcome would suggest that the clinical management of DPAs requires a careful diagnostic approach and follow- up.

Autoimmune hypophysitis: expanding the differential diagnosis to CTLA-4 blockade

Autoimmune hypophysitis is an increasingly recognized disorder that enters in the differential diagnosis of nonfunctioning pituitary masses. The differential diagnosis of these conditions is challenging because of similar clinical presentations and radiological signs. This review describes the essential features of hypophysitis and the other nonfunctioning pituitary masses. It also emphasizes a recently described feature of hypophysitis: its appearance with unexpectedly high frequency in patients receiving treatments that abrogate the function of cytotoxic T lymphocyte antigen 4.

Non-functioning pituitary adenomas

Non-functioning pituitary tumours are mostly of gonadotroph cell origin and are devoid of humoral hypersecretory syndromes. They are usually large at the time of diagnosis, commonly presenting with headaches, visual field defects and hypopituitarism. Trans-sphenoidal surgery remains the treatment of choice for rapid decompression of neighbouring structures, often bringing to normalisation or improvement of visual and pituitary function. The management of patients with postoperative residual tumours is still a matter of debate and may include observation alone, the use of dopamine agonists or radiation therapy. There are no controlled or comparative studies of the available therapeutic options; therefore, recommendations are not evidence based. Patients need long-term follow-up for the detection and treatment of hypopituitarism, visual dysfunction and tumour growth that may develop over time.

A radiologic score to distinguish autoimmune hypophysitis from nonsecreting pituitary adenoma preoperatively

BACKGROUND AND PURPOSE

Autoimmune hypophysitis (AH) mimics the more common nonsecreting pituitary adenomas and can be diagnosed with certainty only histologically. Approximately 40% of patients with AH are still misdiagnosed as having pituitary macroadenoma and undergo unnecessary surgery. MR imaging is currently the best noninvasive diagnostic tool to differentiate AH from nonsecreting adenomas, though no single radiologic sign is diagnostically accurate. The purpose of this study was to develop a scoring system that summarizes numerous MR imaging signs to increase the probability of diagnosing AH before surgery.

MATERIALS AND METHODS

This was a case-control study of 402 patients, which compared the presurgical pituitary MR imaging features of patients with nonsecreting pituitary adenoma and controls with AH. MR images were compared on the basis of 16 morphologic features besides sex, age, and relation to pregnancy.

RESULTS

Only 2 of the 19 proposed features tested lacked prognostic value. When the other 17 predictors were analyzed jointly in a multiple logistic regression model, 8 (relation to pregnancy, pituitary mass volume and symmetry, signal intensity and signal intensity homogeneity after gadolinium administration, posterior pituitary bright spot presence, stalk size, and mucosal swelling) remained significant predictors of a correct classification. The diagnostic score had a global performance of 0.9917 and correctly classified 97% of the patients, with a sensitivity of 92%, a specificity of 99%, a positive predictive value of 97%, and a negative predictive value of 97% for the diagnosis of AH.

CONCLUSIONS

This new radiologic score could be integrated into the management of patients with AH, who derive greater benefit from medical as opposed to surgical treatment.

Stereotactic Radiosurgery with the CyberKnife for Pituitary Adenomas

OBJECTIVE

In recent years, CyberKnife has emerged as an important treatment modality in the management of pituitary adenomas. Treatment results after performing CyberKnife and the complications of this procedure are reviewed.

METHODS

Twenty-six patients with pituitary adenomas received stereotactic radiosurgery with the CyberKnife (CKRS). The follow-up periods ranged from 7 months to 47 months (mean+/-SD : 30+/-12.7 months). The patients consisted of 17 with non-functioning adenomas, 3 with prolactinomas and 6 with acromegaly. The change in the tumor volume, visual acuity, hormonal function, and complications by this therapy were analyzed in each case.

RESULTS

The tumor control rate was 92.3%. Hormonal function was improved in all of the 9 (100%) functioning adenomas. Hormonal normalization was observed in 4 of the 9 (44%) patients with a mean duration of 16 months. In two patients (7.6%), visual acuity worsened due to cystic enlargement of the tumor after CKRS. No other complications were observed.

CONCLUSION

CyberKnife is considered safe and effective in selected patients with pituitary adenomas. However, longer follow-up is required for a more complete assessment of late toxicity and treatment efficacy.