Glioma grading based on histogram analysis of normalized CBV heterogeneity is an alternative to the established hot-spot method, as it offers increased diagnostic accuracy and interobserver agreement.

The classification of neoplasms of adenohypophysial cells is misleading because of the simplistic distinction between adenoma and carcinoma, based solely on metastatic spread and the poor reproducibility and predictive value of the definition of atypical adenomas based on the detection of mitoses or expression of Ki-67 or p53. In addition, the current classification of neoplasms of the anterior pituitary does not accurately reflect the clinical spectrum of behavior. Invasion and regrowth of proliferative lesions and persistence of hormone hypersecretion cause significant morbidity and mortality. We propose a new terminology, pituitary neuroendocrine tumor (PitNET), which is consistent with that used for other neuroendocrine neoplasms and which recognizes the highly variable impact of these tumors on patients.

Densely granulated adenomas were highly responsive to somatostatin analogues in contrast to SG adenomas. The transitional group behaved clinically more like DG adenomas. However, based on E-cadherin, a marker of dedifferentiation, the transitional group seemed to be a true intermediate.

Rabbit monoclonal antibodies are reliable markers of SSTRs in somatotroph adenomas. SSTR2a expression correlated with the response to octreotide and was reduced after octreotide treatment, indicating the need for adjustment when SSTR2a expression is correlated with baseline characteristics. Evaluation of SSTR subtypes may be an important aspect of improving the medical treatment for acromegaly.

In patients with acromegaly, T2 signal intensity at diagnosis correlates with histological features and predicts biochemical outcome of first-line SA treatment.

Summary Objective  Reduced expression of the somatostatin receptor subtype 2 (SSTR2) has been suggested as an explanation for the poor response to octreotide in acromegaly, but studies correlating levels of SSTR2 mRNA to octreotide efficacy have been contradictory. Some studies have found better responses to somatostatin analogues in G‐protein α subunit (Gsα) mutation (gsp oncogene)‐positive adenomas. The aim of this study was to determine adenoma SSTR2a protein expression and gsp status in a large group of patients with acromegaly, and relate this to the clinical effect of octreotide. Patients  Seventy‐one patients were included. All underwent transsphenoidal surgery, 23 patients after preoperative octreotide treatment. Measurements  The adenoma SSTR2a expression was examined by immunohistochemistry and Western blot analysis, and gsp status determined. An acute octreotide test was performed, and the change in IGF‐1 level after 6 months preoperative octreotide treatment was recorded. Results  The acute octreotide response in non‐pretreated patients and the preoperative long‐term octreotide response were significantly better in patients with adenomas containing a large proportion of cells that stained positively for SSTR2a by immunohistochemistry. However, the SSTR2a protein level assessed by Western blot did not correlate with the octreotide response. The preoperatively treated group had lower SSTR2a protein levels and fewer adenomas with a large percentage of positively stained cells. The gsp oncogene was detected in 43% of the adenomas but did not correlate to the octreotide response. Conclusion  The clinical effect of octreotide correlates with the proportion of cells positive for SSTR2a in immunohistochemical staining, rather than the adenoma SSTR2a protein level. There may be a down‐regulation of SSTR2a during octreotide treatment.

Context: Appropriate cell-to-cell adhesion is fundamental for the epithelial phenotype of pituitary cells. Loss of the adhesion protein E-cadherin has been associated with invasiveness, metastasis, and poor prognosis in cancers of epithelial origin. In somatotroph adenomas, a variable and reduced expression of E-cadherin has been demonstrated. In addition, nuclear translocation of E-cadherin was found to correlate with pituitary tumor invasion. Objective: The objective was to examine the protein expression of E-cadherin in somatotroph pituitary adenomas in relation to adenoma size, invasiveness, and somatostatin analog (SMS) efficacy. Patients and Methods: Eighty-three patients were included, and 29 were treated preoperatively with SMS. Adenoma E-cadherin protein expression was analyzed by Western blot (61 patients) and immunohistochemistry (IHC) (80 patients) with antibodies directed against both extracellular and intracellular domains (IHC). The acute (direct surgery group) and long-term (preoperatively treated group) SMS responses were evaluated. Baseline tumor volume and invasiveness were measured on magnetic resonance imaging scans. Results: Membranous E-cadherin was lost in several adenomas. Nine of these were nuclear E-cadherin positive. The E-cadherin protein expression correlated negatively to tumor size and positively to acute SMS response. Low E-cadherin levels (preoperatively treated group only) and loss of membranous E-cadherin correlated to tumor invasiveness. The E-cadherin level correlated positively to tumor reduction after SMS treatment, and adenomas with nuclear E-cadherin staining had lower IGF-I reduction and tumor shrinkage. Preoperatively treated adenomas had reduced E-cadherin protein levels, but the IHC expression was unaltered. Conclusion: Reduced E-cadherin expression may correlate to a dedifferentiated phenotype in the somatotroph pituitary adenomas.

Welander distal myopathy (WDM) is an adult onset autosomal dominant disorder characterized by distal limb weakness, which progresses slowly from the fifth decade. All WDM patients are of Swedish or Finnish descent and share a rare chromosome 2p13 haplotype. We restricted the WDM-associated haplotype followed by whole exome sequencing. Within the conserved haplotype, we identified a single heterozygous mutation c.1150G>A (p.E384K) in T-cell intracellular antigen-1 (TIA1) in all WDM patients investigated (n = 43). The TIA1 protein regulates splicing, and translation through direct interaction with mRNA and the p.E384K mutation is located in the C-terminal Q-rich domain that interacts with the U1-C splicing factor. TIA1 has been shown to prevent skipping of SMN2 exon 7, and we show that WDM patients have increased levels of spliced SMN2 in skeletal muscle cells when compared with controls. Immunostaining of WDM muscle biopsies showed accumulation of TIA1 and stress granulae proteins adjacent to intracellular inclusions, a typical finding in WDM. The combined findings strongly suggest that the TIA1 mutation causes perturbed RNA splicing and cellular stress resulting in WDM. The selection against the mutation is likely to be negligible and the age of the TIA1 founder mutation was calculated to approximately 1,050 years, which coincides with the epoch of early seafaring across the Baltic Sea.