Application of serum mid-infrared spectroscopy combined with an ensemble learning method in rapid diagnosis of gliomas

Diffuse growth of glioma cells leads to gliomatosis, which has a low cure rate and high mortality. This study aims to find an efficient and accurate diagnostic method for glioma by using infrared spectroscopy combined with ensemble learning model and decision level fusion.

Follicular lymphoma t(14;18)-negative is genetically a heterogeneous disease

Fifty-five cases of t(14;18)− follicular lymphoma (FL) were genetically characterized by targeted sequencing and copy number (CN) arrays. t(14;18)− FL predominated in women (M/F 1:2); patients often presented during early clinical stages (71%), and had excellent prognoses. Overall, t(14;18)− FL displayed CN alterations (CNAs) and gene mutations carried by conventional t(14;18)+ FL (cFL), but with different frequencies. The most frequently mutated gene was STAT6 (57%) followed by CREBBP (49%), TNFRSF14 (39%), and KMT2D (27%). t(14;18)− FL showed significantly more STAT6 mutations and lacked MYD88, NOTCH2, MEF2B, and MAP2K1 mutations compared with cFL, nodal marginal zone lymphoma (NMZL), and pediatric-type FL (PTFL). We identified 2 molecular clusters. Cluster A was characterized by TNFRSF14 mutations/1p36 alterations (96%) and frequent mutations in epigenetic regulators, with recurrent loss of 6q21-24 sharing many features with cFL. Cluster B showed few genetic alterations; however, a subgroup with STAT6 mutations concurrent with CREBBP mutations/16p alterations without TNFRSF14 and EZH2 mutations was noted (65%). These 2 molecular clusters did not distinguish cases by inguinal localization, growth pattern, or presence of STAT6 mutations. BCL6 rearrangements were demonstrated in 10 of 45 (22%) cases and did not cluster together. Cases with predominantly inguinal presentation (20 of 50; 40%) had a higher frequency of diffuse growth pattern, STAT6 mutations, CD23 expression, and a lower number of CNAs, in comparison with noninguinal cases (5.1 vs 9.1 alterations per case; P < .05). STAT6 mutations showed a positive correlation with CD23 expression (P < .001). In summary, t(14;18)− FL is genetically a heterogeneous disorder with features that differ from cFL, NMZL, and PTFL.

The Pivotal Novel Pathogenic Roles of Hyaluronic Acid and its Receptors in Gliomas

HA/CD44 as well as HA/RHAMM cross-talks resulted in glioma cell adhesion, mechanosensing, as well as invasive motility. RHAMM was overexpressed in DIPG and may contribute to the diffuse growth pattern and invasion in DIPG just like other forms of gliomas other than CD44. BEHAB/brevican could be a potential biomarker for glioma detection as well as its progression or malignancy.

Cell wall dynamics under conditions of diffuse growth in the thick-walled cortical tissue (prosoplectenchyma) of Ramalina usnea

A recent field study indicated that thalli of the beard lichen Ramalina usnea undergo diffuse (“intercalary”) growth throughout their length. We examined thallus sections with TEM to better understand how the highly thickened cell walls of the prosoplectenchymatous cortex behave under conditions of continued expansion. Cell protoplasts were surrounded by massive accumulations of structured electron-dense wall layers interspersed with amorphous, electron-transparent substances, visible as concentric rings in transverse section. Nearest the protoplast, electron-dense wall layers were distinct and more or less alternated with irregular deposits of electron-transparent material. With increasing distance from the protoplast, the electron-dense wall layers were increasingly disrupted and intermixed among the electron-transparent materials. New cell branches grew through the accumulated wall materials, interrupting the layers they penetrated while producing their own concentric wall layers. The differing amounts of cell wall material accumulated was further indication of the different relative ages of such neighbouring cells. These observations suggest that cell walls are disrupted by diffuse tissue expansion and continually replaced by new walls and wall materials deposited to their interior at the interface with the protoplast. This pattern of development, documented previously in R. menziesii and U. longissima, suggests that component cells of lichen prosoplectenchyma behave quite differently from those of diffusely expanding filaments studied in non-lichen-forming fungi, where a single, discrete cell wall is maintained throughout growth.

Primary Cutaneous Follicle Center Lymphomas (PCFCL) Express Heavily Mutated B-Cell Receptors with Acquired N-Glycosylation Motifs and Lack Ongoing Somatic Hypermutation

Introduction & Objectives: Primary Cutaneous Follicle Center Lymphoma (PCFCL) is a very indolent mature B-cell lymphoma that shares germinal center morphology with follicular lymphoma (FL) but lacks the characteristic t(14;18). Unlike FL, immunohistochemistry fails to detect expression of BCL2, CD10, and immunoglobulin in PCFCL. Therefore, we investigated expression of B-cell receptor (BCR) transcripts to gain insight into the immunobiology of PCFCL. Materials & Methods: Full-length heavy and light chain BCR transcripts of 13 histologically confirmed PCFCL were amplified using ARTISAN PCR and sequenced on the PacBio RSII system. BCR from 4 cases were sequenced to a depth of >2000 sequences per BCR transcript; the remaining cases to a median depth of 1663 sequences (range: 626-5301). BCR from 51 cases of FL and from peripheral B cells of 12 healthy donors were used as controls. Whole genome sequencing (WGS) and RNAseq were performed on 5 PCFCL on the Illumina HiSeq platform. Results: No PCFCL case carried a t(14;18). In addition to previously described CD79B mutations, an L265P mutation in MYD88 was identified in one case, and two PCFCL carried amplifications in chromosome 2 involving the proto-oncogene REL. ARTISAN PCR demonstrated expression of potentially functional VDJ and VJ genes with heavily mutated V regions (VDJ: 5.9-24.0%; VJ: 4.7-17.9%) in all PCFCL cases, which could be confirmed by RNAseq-based de novo BCR assembly. One PCFCL case expressed IgM, another IgA, and the remaining ten cases expressed IgG. PCFCL VDJ carried relatively long heavy chain CDR3 regions with a median of 19 amino acids (versus 17 in healthy donor PBMCs). In contrast to FL, only minimal intraclonal sequence variation (comparable to the known error rate of the used sequencing method) was observed in PCFCL VDJ and VJ sequences, indicating absence of ongoing somatic hypermutation (SHM). VDJ and/or VJ of 11 PCFCL (85%) carried at least one acquired N-linked glycosylation motifs, six PCFCL (46%) at least two, and one case four such motifs. 75% of acquired N-linked glycosylation motifs were found in different positions than the N-linked glycosylation motifs found in FL BCR (Figure). In contrast, only 17.5% and <0.5% of mutated BCR with less than 98% IGV homology to germ-line from healthy donors carried at least one or more acquired N-linked glycosylation motifs, respectively. The PCFCL BCR with the most N-linked glycosylation motifs belonged to the only patient with a lymph node relapse and currently active disease. BCR of PCFCL with an at least partly follicular growth pattern appeared to carry more N-linked glycosylation sites than PCFCL with a strictly diffuse growth pattern (average 1.86 (range: 1-4) versus 0.83 (range: 0-2)), although this difference was not significant (p=0.10). Additionally, 6/7 PCFCL with a follicular growth pattern but none of the PCFCL with a diffuse growth pattern were situated on the scalp (p<0.001). Conclusions: Follicular morphology, class switch recombination, and extensive SHM indicate a shared germinal center B cell origin for both PCFCL and FL. Clonal BCR sequences and previously identified copy number alterations prove that PCFCL represents a neoplastic clonal expansion. However, lack of ongoing SHM indicates that the immune follicles of PCFCL are not fully functional germinal centers. Since ongoing SHM is thought to contribute to lymphomagenesis by targeting non-BCR loci, absence of both ongoing SHM and the t(14;18) may explain the relatively benign clinical course of PCFCL compared to FL. As previously described for FL, continuous BCR stimulation through glycosylation-mediated binding of lectins on resident cells of the follicular microenvironment may play a role in the clonal expansion of PCFCL cells and may orchestrate the follicular microarchitecture in PCFCL. However, the positions of the glycosylated amino acids within the BCR vary between FL and PCFCL and warrant functional studies to clarify their relevance in PCFCL pathogenesis. Figure. Figure. Disclosures Schmidt: Gilead: Honoraria, Other: Travel Grants; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Grants; Celgene: Honoraria.

Structural evidence of diffuse growth and parenchymatous cell division in the cortex of the umbilicate lichen Lasallia pustulata

How growth is distributed within the morphologically diverse thalli of lichens is still poorly known and the anatomical mechanisms involved are not well understood. This work applies electron microscopy (SEM and TEM) to examine cell- and tissue-level events in the umbilicate thallus of Lasallia pustulata, whose pattern of expansion was the subject of a previous field study. Stacks of epinecral tissue accumulating at the thallus surface showed broadening bases and recurring rupture attributable to diffuse expansion of the living tissue below. Cortical cells, dividing anticlinally, adjoined septa to previous septa, indicating parenchymatous divisions. These observations are all consistent with previous contentions that mature, organized tissues within the thallus are capable of continued diffuse growth. They provide a developmental explanation for the morphology of the epinecral layer and suggest that anatomical characteristics may be helpful in recognizing diffuse growth patterns. Parenchymatous cell divisions, believed until recently to never occur in lichen thallus tissues, are shown to play a developmental role in the diffuse growth of the umbilicate lichen thallus.

Adult Granulosa Cell Tumors of the Ovary: A Retrospective Study of 36 FIGO Stage I Cases with Emphasis on Prognostic Pathohistological Features

Objective. Adult granulosa cell tumors (AGCTs) represent 2%–5% of all ovarian malignancies. The aim of this study was to analyze clinical and pathohistological parameters and their impact on recurrence, overall, and disease-free survival in FIGO stage I AGCT patients. Methods. The tumor specimens analyzed in this retrospective study were obtained from a total of 36 patients with diagnosis of ovarian AGCT surgically treated at the Department of Gynecology, Rijeka University Hospital Centre, between 1994 and 2012. Clinical, pathological, and follow-up data were collected. Results. The mean age at diagnosis was 54.5 years with a range of 24–84. The majority of the patients, 30 (83%), were in FIGO stage IA, 3 (8%) in stage IC1, 1 (3%) in stage IC2, and 2 (6%) in stage IC3. During follow-up period (median 117.5 months, range 26–276), recurrence occurred in 4 patients (12%) with 2 deaths of the disease recorded. In univariate analysis, the 5-year survival rates were significantly shorter in patients with FIGO substage IC (p=0.019), with positive LVSI (p=0.022), with presence of necrosis (p=0.040), and with hemorrhage (p=0.017). In univariate analysis, the 5-year disease-free survival rates were significantly shorter in patients treated with fertility surgery (p=0.004), with diffuse growth pattern (p=0.012), with moderate and severe nuclear atypia (p=0.032), and with presence of hemorrhage (p=0.022). FIGO substage IC proved to be independent predictor for recurrence (OR = 16.87, p=0.015, and OR = 23.49, p=0.023, resp.) and disease-free survival (p=0.0002; HR 20.84, p=0.02) at the uni- and multivariate analyses. Conclusions. FIGO substage IC is predictive of recurrence and disease-free survival in patients with early-stage AGCTs. LVSI, presence of necrosis and hemorrhage, diffuse growth pattern, and nuclear atypia in AGCTs seem to be associated with overall and disease-free survival, so these pathological features should be taken into consideration when managing patients with AGCT.