NIMG-29. ELEVATION OF GLUTAMINE AND CITRATE BY MR SPECTROSCOPY IS AN IMAGING BIOMARKER OF RAPID CELL PROLIFERATION IN GLIOMAS

Prior studies suggested glutamine metabolism in cancers may be altered to meet the high demands of nucleotide biosynthesis in cancers. We conducted 1H MR spectroscopy in 18 glioma patients and analyzed the metabolic data together with post-gadolinium MRI and cell proliferation rate (MIB-1 label index). The optimized MRS (TE 97 ms PRESS) provided well discernible signal of glutamine at 2.45 ppm and a negative-polarity signal of citrate at 2.6 ppm, without considerable overlaps with neighboring signals. The 18 patients had biopsy-proven anaplastic gliomas or glioblastomas. Concurrent elevation of glutamine and citrate was identified in 15 gliomas. These gliomas presented with enhancement in post-gadolinium MRI, indicative of broken blood-brain barrier (BBB). The 15 gliomas were grouped as subset-1 while the other 3 gliomas that had elevated citrate without elevation of glutamine were grouped as subset-2. Citrate level was significantly different between the two subsets of gliomas (1.4+/-0.5 vs. 1.6+/-0.4 mM). However, subst-1 had significantly higher choline (4.7+/-1.8 vs. 1.6+/-0.3 mM, p< 0.01) and higher MIB-1 compared with subset-2. Given that choline is a cellularity marker, a finding of high choline and high MIB-1 with elevation of glutamine and citrate suggests that the tumors have high tumor cellularity and cell multiplication competence. Of the 18 gliomas, 13 were IDH mutated with elevated 2HG. The glutamine and citrate levels in IDH-mutant gliomas were not significantly different from those in IDH wildtype gliomas. In conclusion, high-grade gliomas undergo a metabolic rearrangement of concurrent elevation of glutamine and citrate to attain malignant characters such as high cellularity, rapid cell proliferation, and BBB breakdown. IDH mutant and IDH wildtype gliomas may share a common metabolic rearrangement of glutamine-mediated citrate elevation to attain malignancy. Measurements of glutamine and citrate may serve a potential imaging biomarker for aggressive gliomas.

Dopamine secreting pheochromocytoma and paraganglioma

Predominantly or exclusively dopamine-secreting pheochromocytoma and paraganglioma are very rare. We report a 64-year-old woman with an adrenal incidentaloma. She was normotensive and had no symptoms of catecholamine excess. The 24-hour urine catecholamine level showed normal norepinephrine (122.9 μg/day), epinephrine (24.3 μg/day), whereas markedly elevated dopamine (148,212.4 μg/day). 123I-metaiodobenzylguanidine (MIBG) scintigraphy revealed tumor uptake. After α-blockade as preoperative management, she successfully underwent laparoscopic left adrenalectomy and was finally diagnosed with an exclusively dopamine-secreting pheochromocytoma. The tumor was histologically comprised of small polygonal cells with high cellularity and was immunohistochemically positive for all three catecholamine synthesizing enzymes: tyrosine hydroxylase (very weak), dopamine β-hydroxylase (heterogeneous), and phenylethanolamine N-methyltransferase (very weak). Electron microscopy revealed very few catecholamine-containing small vesicles with a few organelles, which reflected immature cells. No biochemical or imaging evidence of recurrence or metastasis were evident 1 year after the surgery. We conducted a literature search in the Pubmed database. A total of 33 cases were collected. Our case had the second-highest 24-hour urinary dopamine excretion and was the first in which immunostaining for catecholamine synthase and electron microscopy were performed together. Histological findings in our case give a possible hypothesis that the mechanism underlying a dopamine-secreting pheochromocytoma is associated with immature catecholamine vesicles in which DBH is localized, thus resulting in inhibited conversion from dopamine to norepinephrine. We also discuss the reasons for the lack of catecholamine excess symptoms, whether preoperative management of α-blockade is needed, and the association between the prognosis and genetic mutation with an extensive literature review.

Penile Squamous Cell Carcinoma in A Boerboel Dog in Ibadan, Nigeria – A Case Report

This report describes the first case of penile squamous cell carcinoma (SCC) in a Boerboel from our environment while emphasizing the importance of cytology as a quick and reliable diagnostic tool in clinical setting. The dog presented with a complaint of bloody urination had a noticeable growth on the penis. There was high cellularity of neoplastic squamous cells admixed numerous neutrophils and keratin within the background upon cytological evaluation. Therefore, cytological evaluation can become a ready tool for the diagnosis of SCC for appropriate treatment.

On Clustering for Cell Phenotyping in Multiplex Immunohistochemistry (mIHC) and Multiplexed Ion Beam Imaging (MIBI) Data

Problem: Multiplex immunohistochemistry (mIHC) and multiplexed ion beam imaging (MIBI) images are usually phenotyped using a manual thresholding process. The thresholding is prone to biases, especially when examining multiple images with high cellularity. Results: Unsupervised cell phenotyping methods including PhenoGraph, flowMeans, and SamSPECTRAL, primarily used in flow cytometry data, often perform poorly or need elaborate tuning to perform well in the context of mIHC and MIBI data. We show that, instead, semi-supervised cell clustering using Random Forests, linear and quadratic discriminant analysis are superior. We test the performance of the methods on two mIHC datasets from the University of Colorado School of Medicine and a publicly available MIBI dataset. Each dataset contains numerous highly complex images.

Clinical, Histological, and Molecular Features of Solitary Fibrous Tumor of Bone: A Single Institution Retrospective Review

Primary solitary fibrous tumor (SFT) of the bone is extremely rare, with only few cases reported in the literature. We retrieved all cases of primary SFT of the bone treated at our institution and we assessed the morphology and the immunohistochemical and molecular features to investigate the clinical outcome of primary SFT of the bone and any clinical relevance of clinical and histological criteria of aggressiveness currently adopted for the soft tissues counterpart. Morphologically, 15 cases evidenced high cellularity, cytologic atypia, and foci of necrosis and were associated with more than 4 mitotic figures/10 HPF. Immunohistochemical analysis showed an expression of CD34 and of STAT6 immunopositivity in 95% and in 100% of cases, respectively. The presence of NAB2-STAT6 chimeric transcripts was found in 10 out of 12 cases in which RT-PCR analysis was feasible, whereas TERT promoter mutations analysis was feasible in 16 cases and only a C-to-T substitution in a heterozygous state was found in one DNA sample for the C228T genetic variant. P53 variants were assessed in 12 cases: 11 (91.6%) cases showed a variation, while in one case, no alteration was found. Disease-specific survival was 64% at 5 years and 49% at 10 years. Statistical analysis showed no correlation between survival and all the clinicopathological and molecular parameters evaluated. In conclusion, at difference to SFT of soft tissues, aggressive behavior of primary SFT of the bone seems to be independent from mitotic count or any other clinicopathological and molecular features.

Connect your needle to a smartphone to increase EUS FNA sample quality and diagnostic accuracy of solid pancreatic masses: a randomized trial

Background and study aims. EUS FNA is recommended for diagnosis of solid pancreatic masses. We aimed to evaluate if a high needle movement acceleration value during puncture increases diagnostic accuracy. Patients and methods. EUS FNA needle acceleration was measured using a PocketLab accelerometer connected by Bluetooth to a smartphone. Two passes (fast and slow) with higher and respectively lower than 1g needle acceleration values were performed in random order. Sample cellularity and quality were measured by semiquantitative scales. Results. 51 patients were included (32 women, mean age 63). Mean acceleration values were 1.59 ± 0.66g for fast pass and 0.32 ± 0.19g for slow pass, p < 10-3. Fast pass yielded significantly higher EUS FNA accuracy (84.3% vs. 68.6%, p = 0.021) and adequate quality scores (94.1% vs. 76.5%, p = 0.007). High cellularity score frequencies were similar (15.7% vs. 11.8%, p = 0.317). Conclusions. A higher than 1g EUS FNA needle acceleration may increase diagnostic accuracy and specimen quality of pancreatic solid lesions.

Static Osteogenesis Versus Dynamic Osteogenesis: A Comparison between Two Different Types of Bone Formation

In contrary to what has traditionally been believed, bone formation can occur through two different types of osteogenesis: static (SO) and dynamic (DO) osteogenesis, which are thus named because the former is characterized by pluristratified cords of unexpectedly stationary osteoblasts which differentiate at a fairly constant distance from the blood capillaries and transform into osteocytes without moving from the onset site, while the latter is distinguished by the well-known typical monostratified laminae of movable osteoblasts. The two types of osteogenesis differ in multiple aspects from both structural and functional viewpoints. Besides osteoblast arrangement, polarization, and motion, SO and DO differ in terms of time of occurrence (first SO and later DO), conditioning factors to which they are sensitive (endothelial-derived cytokines or mechanical loading, respectively), distribution of osteocytes to which they give rise (haphazard or ordered in planes, respectively), the collagen texture resulting from the different deposition types (woven or lamellar, respectively), the mechanical properties of the bone they form (poor for SO due to the high cellularity and woven texture and good for DO since osteocytes are located in more suitable conditions to perceive loading), and finally the functions of each, i.e., SO provides a preliminary rigid scaffold on which DO can take place, while DO produces bone tissue according to mechanical/metabolic needs..

PATH-23. ADULT SPINAL CORD ASTROBLASTOMA WITH EWSR1-BEND2 FUSION

The most recurrent fusion of CNS high-grade neuroepithelial tumor with MN1alteration(HGNET-MN1) is MN1- BEN Domain Containing 2(BEND2) fusion. Recently, there was a report of a 3-month-old boy with spinal astroblastoma, classified as CNS HGNET-MN1 by DKFZ methylation classification but positive for EWSR1-BEND2 fusion(Yamasaki, 2019). Here, we report a 36-year old man with a spinal cord astroblastoma with EWSR1 alternation. The patient presented with back pain, gait disorder and dysesthesia in lower extremities and trunk was referred to our hospital. MRI showed intramedullary tumor in Th3-5 level, displaying low-intensity on T1 weighted image, high-intensity on T2 weighted image, and homogeneous gadolinium enhancement. Partial removal was performed with the laminectomy. The tumor extended to extramedullary and its boundary was unclear. Histological examinations showed the epithelium-like tumor cells with eosinophilic cytoplasm with high cellularity palisade, intracellar fibrosis, and mitosis. Immunohistochemical staining showed positive for Olig2, GFAP, EMA, SSTR2, S-100, but negative for p53, PgRAE1/AE3. The tumor was diagnosed as astroblastoma, and was classified as HGNET-MN1 by the DKFZ methylation classifier. However, the MN1 alternation was not detected by fluorescence in situ hybridization, instead EWSR1 and BEND2 alternations which suggested EWSR1-BEND2 fusion were detected. After radiation therapy of 54Gy/30fr with bevacizumab and temozolomide, the residual tumor reduced the size and his symptoms improved. This case provides evidence that EWSR1-BEND2 fusion is recurrent in HGNET-MN1 and, as previously reported, suggests the importance of BEND2 in this entity. These two cases suggested that it may be the BEND2 alteration that biologically defines the HGNET-MN1 subclass rather than MN1.

Cutaneous leiomyosarcoma / atypical smooth muscle sarcoma

Relevance: Cutaneous leiomyosarcoma is a rare primary dermal neoplasm, accounting for up to 2-3% of all superficial sarcomas. It can occur at any age, most likely between the ages of 50 and 70 years. This tumor has a high recurrence potential in case of insufficiently deep excision. Recurrent tumors are more aggressive and characterized by subsequent metastasis. The purpose of the study was to demonstrate the results of the histopathological examination of a cutaneous leiomyosarcoma / atypical smooth muscle tumor. Results: Cutaneous leiomyosarcoma was represented by spindle-shaped cells with high cellularity located in bundles and growing expansively, surrounded by a capsule. The nuclei of the cells were elongated, hyperchromic. Cells with atypical abnormal nuclei were present in smaller quantities. The mitoses, including atypical, were numerous. IHC staining for SMA, Desmin, H-Caldesmon – diffusely positive on tumor cells. The reaction for S100, Myogenin – negative. Conclusion: A cutaneous leiomyosarcoma can be finally diagnosed only after a pathomorphological examination of the specimen and differential diagnostics using additional research methods.

Cutaneous leiomyosarcoma/ atypical smooth muscle sarcoma

Relevance: Cutaneous leiomyosarcoma is a rare primary dermal neoplasm, accounting for up to 2-3% of all superficial sarcomas. It can occur at any age, most likely between the ages of 50 and 70 years. This tumor has a high recurrence potential in case of insufficiently deep excision. Recurrent tumors are more aggressive and characterized by subsequent metastasis. The purpose of the study was to demonstrate the results of the histopathological examination of a cutaneous leiomyosarcoma / atypical smooth muscle tumor. Results: Cutaneous leiomyosarcoma was represented by spindle-shaped cells with high cellularity located in bundles and growing expansively, surrounded by a capsule. The nuclei of the cells were elongated, hyperchromic. Cells with atypical abnormal nuclei were present in smaller quantities. The mitoses, including atypical, were numerous. IHC staining for SMA, Desmin, H-Caldesmon – diffusely positive on tumor cells. The reaction for S100, Myogenin – negative. Conclusion: A cutaneous leiomyosarcoma can be finally diagnosed only after a pathomorphological examination of the specimen and differential diagnostics using additional research methods