An Update on Pituitary Neuroendocrine Tumors Leading to Acromegaly and Gigantism

An excess of growth hormone (GH) results in accelerated growth and in childhood, the clinical manifestation is gigantism. When GH excess has its onset after epiphyseal fusion at puberty, the overgrowth of soft tissue and bone results in acromegaly. Persistent GH excess in gigantism also causes acromegalic features that become evident in the adult years. The causes of GH excess are primarily lesions in the pituitary, which is the main source of GH. In this review, we provide an update on the clinical, radiological and pathologic features of the various types of pituitary neuroendocrine tumors (PitNETs) that produce GH. These tumors are all derived from PIT1-lineage cells. Those composed of somatotrophs may be densely granulated, resembling normal somatotrophs, or sparsely granulated with unusual fibrous bodies. Those composed of mammosomatotrophs also produce prolactin; rare plurihormonal tumors composed of cells that resemble mammosomatotrophs also produce TSH. Some PitNETs are composed of immature PIT1-lineage cells that do not resemble differentiated somatotrophs, mammosomatotrophs, lactotroph or thyrotrophs; these tumors may cause GH excess. An unusual oncocytic PIT1-lineage tumor known as the acidophil stem cell tumor is predominantly a lactotroph tumor but may express GH. Immature PIT1-lineage cells that express variable amounts of hormones alone or in combination can sometimes cause GH excess. Unusual tumors that do not follow normal lineage differentiation may also secrete GH. Exceptional examples of acromegaly/gigantism are caused by sellar tumors composed of hypothalamic GHRH-producing neurons, alone or associated with a sparsely granulated somatotroph tumor. Each of these various tumors has distinct clinical, biochemical and radiological features. Data from careful studies based on morphologic subtyping indicate that morphologic classification has both prognostic and predictive value.

MORPHOLOGIC CLASSIFICATION OF THE BESKIDS ROCKS IN THE UKRAINIAN CARPATHIANS

The article deals with morphological classification of the sandstone rocks in the Ukrainian Carpathians Beskids. By the methods of field measurements and mathematical computations the rock peaks heights, their shape, basement lengths and strata thickness have been calculated. The highest rock peaks in the Beskids amounts 32–37 m. The classification from the morphological point of view on the base of rock forms studying has been done. All rocks are divided in two classes: the rocks-outliers and the rocks-outcrops. Among the rocks-outliers 4 types are defined: spire-shaped, chain-shaped, arc-shaped and combined. Spire-shaped rocks are divided into subtypes: tower, spoke and needle. Among the chain-shaped rocks 3 subtypes are defined: wall, bloc and slab. The rocks of combined form are divided into subtypes: 1) with defined form – those of the rocks which are similar to certain objects and 2) undefined forms (cliffs). Among the rocks-outcrops three types are defined: cliff-shaped, canyon-shaped and angular ones. The class of rocks-outliers occurs most often. Among the types the rocks-towers occur most often. They dominate in the rock formations of Urych, Yamelnytsia and Bubnyshche. Many bloc-shaped and plate-shaped rocks are located on the Kliuch Ridge, in Bubnys’ki Rocks, Yamelnytsia. There are rocks-walls of 50–60 m in Urych and Yamelnytsia. The longest rock-wall in Danylov tract near Yamelnytsia has been investigated. Its length is 150 m and height is 17 m. Some needle and spoke rocks are situated in Bubnys’ki Rocks (Odinets’ Rock, Golets’ Rock) and Urych (Hostryi Kamin’ (Sharp Stone) Rock. Unique types are very rare. For instance: Bronenosets’ Rock in Bubnys’ki Rocks (this rock has shape of sail), Sokil (Falcon) Rock in the Kliuch Ridge, mushroom-shaped rock in Yamelnytsia. There is also unique arc-rock in the Kliuch Ridge. In the class of rocks-outcrops the types of cliff and canyon occur equally. The angular-shaped rocks are rarer. The cliff-shaped rocks are situated near Sokolova Mountain, Pozhernytsia Mountain and Kniazhi (Princes) Rocks near Tyshivnytsia. Unique rocks-canyons, the effects of tectonic breaking and gravity-erosion processes, occur on the Kliuch Ridge. The worked out morphological classification of rocks can be used by ascertaining features of rock morphogenesis with education and scientific purposes as well as by assessment of safety level and protection possibilities. Morphological types of the rocks can be considered as valuable objects of geomorphologic heritage and attractions for geo-tourism. Key words: rocks; morphology type of the rock; rock shape; Beskids of Ukrainian Carpathians.

Reliability and Validity of the AOSpine Thoracolumbar Injury Classification System: A Systematic Review

Study Design: Systematic review. Objectives: The AOSpine thoracolumbar injury classification system (ATLICS) is a relatively simple yet comprehensive classification of spine injuries introduced in 2013. This systematic review summarizes the evidence on measurement properties of this new classification, particularly the reliability and validity of the main morphologic injury types with and without inclusion of the subtypes. Methods: A literature search was performed using PubMed and Embase in September 2016. A revised version of the COSMIN checklist was used for evaluation of the quality of studies. Two independent reviewers performed all steps of the review. Results: Nine articles were included in the final review, all of which evaluated the reliability of the ATLICS and had a fair methodological quality. The reliability of the modifiers was unknown. Overall, the quality of evidence for reliability of the morphologic and neurologic classification sections was low. However, there was moderate evidence for poor interobserver reliability of the morphologic classification when all subtypes were included, and moderate evidence for good intraobserver reliability with exclusion of subtypes. The reliability of the morphologic classification was independent of the observer’s experience and cultural background. Conclusions: ATLICS represents the most current system for evaluation of thoracolumbar injuries. Based on this review, further studies with robust methodological quality are needed to evaluate the measurement properties of ATLICS. Shortcomings of the reliability studies are discussed.

The Banff Working Group Classification of Definitive Polyomavirus Nephropathy: Morphologic Definitions and Clinical Correlations

Polyomavirus nephropathy (PVN) is a common viral infection of renal allografts, with biopsy-proven incidence of approximately 5%. A generally accepted morphologic classification of definitive PVN that groups histologic changes, reflects clinical presentation, and facilitates comparative outcome analyses is lacking. Here, we report a morphologic classification scheme for definitive PVN from the Banff Working Group on Polyomavirus Nephropathy, comprising nine transplant centers in the United States and Europe. This study represents the largest systematic analysis of definitive PVN undertaken thus far. In a retrospective fashion, clinical data were collected from 192 patients and correlated with morphologic findings from index biopsies at the time of initial PVN diagnosis. Histologic features were centrally scored according to Banff guidelines, including additional semiquantitative histologic assessment of intrarenal polyomavirus replication/load levels. In-depth statistical analyses, including mixed effects repeated measures models and logistic regression, revealed two independent histologic variables to be most significantly associated with clinical presentation: intrarenal polyomavirus load levels and Banff interstitial fibrosis ci scores. These two statistically determined histologic variables formed the basis for the definition of three PVN classes that correlated strongest with three clinical parameters: presentation at time of index biopsy, serum creatinine levels/renal function over 24 months of follow-up, and graft failure. The PVN classes 1–3 as described here can easily be recognized in routine renal biopsy specimens. We recommend using this morphologic PVN classification scheme for diagnostic communication, especially at the time of index diagnosis, and in scientific studies to improve comparative data analysis.