Spitz nevus is relatively frequent in adults - A clinico-pathologic study of 247 cases related to patient's age

Spitz nevus is a clinico-pathologic entity that can cause diagnostic concern, particularly in adults. Many studies have been performed to establish reliable histologic criteria, in the attempt to differentiate this lesion from melanoma. A series of 247 Spitz nevi, 6 of which were formerly classified as melanomas, were reviewed for clinical and histopathological parameters. Patients older than 20 comprised 66% of cases, with a predominance of women. The lower extremity was more affected in females of any age, whereas the trunk was more frequently involved in men over 40. Histopathologic examination showed the following differences among Spitz nevi related to age: acanthosis, parakeratosis, pagetoid infiltration, and Kamino bodies were more frequent in young people, whereas multinucleated melanocytes were more frequent in adults. The latter also had lesions that were less pigmented, with less maturation and more desmoplasia. At a mean follow-up of 94 months (range 52-172), recurrence at the site of biopsy or metastases were absent. In our study, a greater proportion of Spitz nevi occurred in adults than in previous series. Moreover, the relative incidence of Spitz nevus compared with melanoma in our population was higher than in other studies. Histopathologic criteria elaborated to diagnose Spitz nevus, applied to our cases, appeared reliable, allowing a correct diagnosis, even in adults

TEM TEXTURE AND X-RAY SINGLE-CRYSTAL STUDY OF SERRA-DE-MAGE ORTHO-PYROXENE

A combined Transmission Electron Microscopy (TEM), X-ray single crystal diffraction (XRD) and microprobe study was undertaken on the orthopyroxene of Serra de Mage feldspar cumulate eucrite. Two single crystals, natural and equilibrated at several temperatures, were examined in order to identify the true symmetry of the orthopyroxene and to estimate the cooling history of the meteorite. TEM texture analysis showed augite lamellae larger than 500 A irregularly spaced within the orthopyroxene matrix, with orientation parallel to (100). XRD data were collected using a four-circle diffractometer. Structural refinement carried out in space group Pbca converged to a discrepancy factor of R = 2.81%. Because of the presence of some Okl 'forbidden' reflections that may be explained either by P21ca symmetry of the orthopyroxene or by overlap of reflections from the exsolved C2/c clinopyroxene, structural refinement in space group P21ca was also attempted. The resulting discrepancy factor was very close to that obtained in Pbca; however, the anomalous values of many thermal parameters and cation-oxygen bond distances do not support the choice of the P21ca space group. Calibration or KD (KD = (Fe(2+) + Mn)M1(MgM2/(Fe(2+) + Mn)MZMgM1) vs. 1/T gave a closure temperature Tc for the intracrystalline Fe(2+)-Mg exchange reaction of about 470 C, consistent with a relatively slow cooling rate

Methane-related carbonates in the Miocene Apennine foredeep (Italy). Sedimentological, mineralogical and geochemical considerations.

Seep carbonate deposits with very negative δ13C values (chemoherms) are documented from various tectonic settings such as convergent plate boundaries, active transform and passive continental margins. In the middle Miocene foredeep basin of the northern Apennines, several pelitic intervals intercalated within turbidite sediments include carbonate bodies interpreted as chemoherms on the basis of isotopic data (δ13C as low as – 41.33 ‰ PDB) and paleontological evidences. These bodies are associated to features of intense sediment instability such as slumps, intraformational breccias and olistostromes. Sedimentological, mineralogical, chemical and isotopic studies where carried out on in-situ carbonate bodies from two of these pelitic intervals in order to reconstruct fluid sources and chemoherm genetical mechanisms and to document the connection between fluid seepage and syndepositional tectonics. Massive (micritic) carbonate authigenic phases of chemoherms consist of low Mg- and Sr-calcite and/or aragonite. Non stoichiometric dolomite and minor amounts of sulphur phases (sulphides and Ca sulphate) are concentrated in the brecciated lower portion of the bodies. Main carbonate phases from the muddy sediments which host the chemoherms consist of high Mg- and Sr-calcite with minor amounts of non-stoichiometric dolomite. The turbidite sediments (Te interval) differ from the pelites by containing significant amounts of stoichiometric (detrital) dolomite. Mineralogical analysis of the carbonate phases reveals that chemoherm bodies are richer in detrital quartz and in chlorite- smectite and lower in illite than the surrounding pelites. Differences are also observed in the distribution of some paleoenviromental indicator elements (Ni, Co, Cu, Zn), which indicate unstable oxidative conditions during or after chemoherm precipitation. Isotopic data (δ13C values as low as –20.31 ‰ PDB) of carbonates from pelites that surround the chemoherms indicate that the carbon is at least in part of biogenic origin and probably related to diffusion of CO2 and methane-rich fluids through the sea floor around the main vents where chemoherms grow. Mineralogical (enrichment in smectite and dolomite, Ca sulphate precipitation) and chemical (high chlorine content) features of some chemoherm bodies suggest that the aqueous fluids associated to the seeping gas were highly saline brines of problematic origin. Some features suggest genetical analogies between the chemoherm deposition in the Miocene foredeep basin and present sedimentary conditions where gas hydrates are generated. It is hypothesized that the pelitic intervals represent sedimentary episodes on top of ephemeral structural highs related to blind faults linked to the advancement of Northern Apennine deformational front. It is possible that the growth of structural highs was an effective mechanism for concentrating gas hydrates by gradually raising the base of their stability zone. Gas hydrates or similar fluids could have played an important role in triggering sediment instability and slumping along the margins of structural highs. The relation between methane seepage, sediment slumping and tectonics suggests a reinterpretation of many chaotic deposits and soft-sediment deformation features as a product of the episodic release of overpressured shallow methane accumulations in slope sediments

Laparoscopic Radical Cystectomy: a 5-year review of a single institute's operative data and complications and a systematic review of the literature

OBJECTIVE: We aim to evaluate our experience and results with laparoscopic radical cystectomy and conduct a systematic review of studies reporting on 50 or more procedures. MATERIALS AND METHODS: Between February 2006 and March 2011, a prospective study in a single institute on patients with bladder cancer who underwent laparoscopic radical cystectomy was conducted. A search of the Cochrane Library, PubMed, Medline, and Scopus databases was conducted for studies reporting on 50 or more laparoscopic radical cystectomy procedures to compare with our results. RESULTS: Sixty men and five women underwent laparoscopic radical cystectomy during the 5-year study period. Thirty-nine patients were submitted to ileal conduits, 24 to neobladders, and two patients to ureterocutaneostomies. The mean operative time was 294 ± 27 minutes, the mean blood loss was 249.69 ± 95.59 millilitres, the mean length of hospital stay was 9.42 ± 2 days, the mean morphine requirement was 3.69 ± 0.8 days. The overall complication rate was 44.6% (29/65). However, the majority of the patients with complications (90% (26/29)) had minor complications treated conservatively with no further surgical intervention needed. The literature search found seven studies, which reported on their institutions' laparoscopic radical cystectomy results of 50 or more patients. Generally, our results were similar to other reported studies of the same calibre. CONCLUSION: Laparoscopic radical cystectomy is a safe and efficient modality of treatment of bladder cancer. However, it comes with a steep learning curve, once overcome, can provide an alternative to open radical cystectomy