"Bone in the penis" or fasciitis ossificans of the penis - a first time description of a pseudo-tumor at an extraordinary site

BACKGROUND

Fasciitis ossificans is a rare subtype of nodular fasciitis, a benign soft tissue tumor with reactive characteristics. Due to its rapid growth, it is often misdiagnosed as a malignant tumor. While fasciitis ossificans commonly originates from the subcutaneous tissue and can appear throughout the body, it may also arise from extraordinary sites.

CASE PRESENTATION

We report the first-ever documented case of fasciitis ossificans arising from the penis in a male patient who presented with a tumor on the glans penis. The tumor was surgically resected due to suspicion of penile cancer. Initial histopathological analysis led to a misdiagnosis of squamous cell carcinoma. However, pathological consultation ultimately confirmed the diagnosis of fasciitis ossificans of the penis originating from the glans penis by demonstrating ossification.

CONCLUSION

This case underscores the importance of considering fasciitis ossificans in the differential diagnosis of soft tissue tumors, even in unusual locations such as penile soft tissue.

Omission of lateral lymph node dissection in medullary thyroid cancer without a desmoplastic stromal reaction

BACKGROUND

Medullary thyroid cancer can be subdivided during surgery into tumours with or without a desmoplastic stromal reaction (DSR). DSR positivity is regarded as a sign of disposition to metastasize. The aim of this study was to analyse whether lateral lymph node dissection can be omitted in patients with DSR-negative tumours.

METHODS

This was a retrospective cohort study of a prospectively maintained database of patients with medullary thyroid cancer treated using a standardized protocol, and subdivided into DSR-negative and -positive groups based on the results of intraoperative frozen-section analysis. Patients in the DSR-negative group did not undergo lateral lymph node dissection. Long-term clinical and biochemical follow-up data were collected, and baseline parameters and histopathological characteristics were compared between groups.

RESULTS

The study included 360 patients. In the DSR-negative group (17.8 per cent of all tumours) no patient had lateral lymph node or distant metastases at diagnosis or during follow-up, and all patients were biochemically cured. In the DSR-positive group (82.2 per cent of all tumours), lymph node and distant metastases were present in 31.4 and 6.4 per cent of patients respectively. DSR-negative tumours were more often stage pT1a and were significantly smaller. The median levels of basal calcitonin and carcinoembryonic antigen were significantly lower in the DSR-negative group, although when adjusted for T category both showed widely overlapping ranges.

CONCLUSION

Lymph node surgery may be individualized in medullary thyroid cancer based on intraoperative analysis of the DSR. Patients with DSR-negative tumours do not require lateral lymph node dissection.

Neuroendocrine liver metastasis from the small intestine: Is surgery beneficial for survival?

BACKGROUND

Neuroendocrine neoplasia of the small intestine (siNEN) are frequently diagnosed with liver metastases. The impact of the presence of liver metastases on overall survival and the necessity of surgery for liver metastasis is discussed controversially. The aim of this study is to evaluate and compare the overall long-term survival of patients with siNENs with and without liver metastasis at initial diagnosis and the possible benefit of surgical treatment as compared to active surveillance of metastases. 123 consecutive patients with siNENs were treated between 1965 and 2016. All clinical and histological records were reevaluated including analysis of the proliferation rates in all specimens. The 1-, 5-, 10- and 20-year overall survival was estimated by Kaplan-Meier analysis for patients with and without liver metastasis and according to the type of treatment (surgical vs. surveillance) of liver metastases if present.

RESULTS

The 1-, 5-, 10- and 20-year overall survival rate was 89.0%, 68.4%, 52.8% and 31.0% in patients without and 89.5%, 69.5%, 33.2% and 3.6% in those with liver metastases. No statistically significant differences were observed comparing the two groups. Within the group of patients with liver metastases, the type of treatment (surgical vs. surveillance) was in favor of patients undergoing surgery. Multivariate analysis showed that the presence of liver metastases upon diagnosis was an individual risk factor associated with worse survival.

CONCLUSION

The presence of liver metastasis at initial diagnosis does not have a statistically significant influence on survival. Surgery for hepatic metastasis seems to show a benefit for overall survival and may be indicated especially in patients symptomatic due to high tumor burden and serotonin hypersecretion to reduce hormone activity.

Early Diagnosis of Medullary Thyroid Cancer: Are Calcitonin Stimulation Tests Still Indicated in the Era of Highly Sensitive Calcitonin Immunoassays?

Background: Measurements of both basal (b) calcitonin (CT) and calcium (Ca)-stimulated CT (Ca-sCT) levels are performed to identify medullary thyroid cancer (MTC) at an early stage when used as part of the diagnostic workup of thyroid nodules (CT screening). Novel immunochemiluminometric assays, which are highly sensitive and specific for monomeric CT and avoid cross-reactivity, have been introduced over the past decade. No prospectively generated data have so far become available to answer the frequently raised question as to whether Ca-sCT in contrast to bCT alone is helpful and, therefore, still indicated for the early detection of MTC. Methods: Ca-stimulation tests were performed in 149 consecutive patients with thyroid nodules and elevated bCT. Regardless of Ca-sCT levels, all patients had an operation applying a uniform surgical protocol, including thyroidectomy and systematic lymph node dissection. Recently published sex-specific cutoff levels for the differentiation of MTC and other C-cell pathologies (C-cell hyperplasia [CCH]) were used to compare the diagnostic performance of bCT or Ca-sCT alone and in combination using receiver-operating characteristic (ROC) analysis. In addition, CT cutoff levels to predict lateral lymph node metastasis were evaluated for bCT compared with Ca-sCT. Follow-up for all patients was documented and correlated with initial CT levels. Results: MTC was identified in 76 (50.1%) patients, in 21/76 (27.6%) with lymph node and in 4 (5.3%) with distant metastasis. Using predefined cutoff levels, patients could effectively be subdivided into a group above the cutoff level with definitive diagnosis of MTC (100%) and below (gray zone) with a significant overlap of CCH and MTC (all classified as pT1a; males: 19/58 [37.5%], females: 7/41 [17.1%]). The areas under the ROC curve (AUC) were excellent for the diagnosis of MTC in all tests. Determination of bCT proved to be superior for both diagnosing MTC in males (AUC for bCT: 0.894; AUC for Ca-sCT: 0.849) and females (bCT: 0.935; Ca-sCT: 0.868) and also for diagnosing lymph node metastasis in the lateral compartment (males: bCT: 0.925; Ca-sCT: 0.810; females: bCT: 0.797; Ca-sCT: 0.674). Combining both tests did not improve diagnostic accuracy. Using a cutoff level of >85 pg/mL for females and >100 pg/mL for males, the sensitivity for diagnosing lateral neck lymph node metastasis was 100%. Below these cutoff levels, no patient showed persistent or recurrent disease (median follow-up: 46 [ ± 27] months). Conclusions: Predefined sex-specific bCT cutoff levels are helpful for the early detection of MTC and for predicting lateral neck lymph node metastasis. Ca-sCT did not improve preoperative diagnostics. bCT levels >43 and >100 pg/mL for males and of >23 and >85 pg/mL for females are relevant for advising patients and planning the extent of surgery.

Positive central lymph-nodes are underdiagnosed in patients with Bethesda V cytology in an endemic goiter region

Background

Fine needle aspiration (FNA) is a significant diagnostic procedure for detecting malignancy in patients with nodular thyroid disease. A high proportion of patients with cytological diagnosed follicular neoplasia (Bethesda IV and V) ultimately have thyroid cancer. The aim of this study was to evaluate the incidence of preoperatively undiagnosed central lymph node metastasis in patients with multinodular goiter (MNG).

Methods

Patients who underwent FNA and were classified as Bethesda IV/V were included. Applying a radical approach, all patients underwent (hemi)thyroidectomy and prophylactic unilateral central neck dissection.

Results

During our study period 2009-2013, 60 patients (19.7%) were classified as Bethesda IV and 21 (6.9%) Bethesda V. Final histopathological results revealed malignancy in 35 (43.2%) of 81 Bethesda IV/V nodules. Of the nodules classified as Bethesda IV, 20 (33.3%) showed malignancy in the final histology. Ten patients (16.7%) had papillary micro-carcinoma (mPTC, <10 mm), 4 (6.6%) PTC and 6 (10%) follicular thyroid cancer. Fifteen of 21 (71.4%) Bethesda V nodules were revealed as PTC of whom seven (33.3%) patients also had lymph-node metastases.

Conclusions

While 33.3% of the patients with PTC, preoperatively classified as Bethesda V, had previously undetected positive lymph-nodes, only one patient with Bethesda IV had lymph-node metastasis.

Calcium-stimulated calcitonin - The "new standard" in the diagnosis of thyroid C-cell disease - clinically relevant gender-specific cut-off levels for an "old test"

Introduction

Pentagastrin (Pg) stimulated calcitonin (sCT) was used to enhance accuracy in medullary thyroid cancer (MTC) diagnosis. As it is now unavailable, calcium (Ca) has been recommended as an alternative. The aim of this study was to define gender-specific cut-off values to predict MTC in patients with elevated basal CT (bCT) following Pg-sCT and Ca-sCT stimulation and to compare the time courses of CT release during stimulation.

Materials and methods

The stimulation tests were applied in 62 consecutive patients with thyroid nodules. Basal calcitonin was measured by chemiluminescent immunometric assay. All patients underwent thyroidectomy and bilateral central neck dissection. C-cell pathology was confirmed by histological and immunohistochemical evaluation.

Results

In 39 (0.63) patients MTC was documented while isolated C-cell hyperplasia (CCH) was identified in 23 (0.37) patients. Medullary thyroid cancer was predicted in males with bCT values > 43 pg/mL or sCT concentrations > 470 pg/mL (Pg-sCT) or > 1500 pg/mL (Ca-sCT), and in females with bCT concentrations > 23 pg/mL or sCT concentrations > 200 pg/mL (Pg-sCT) or > 780 pg/mL (Ca-sCT), respectively. Pg-sCT correctly predicted MTC in 16 (0.66) compared to 13 (0.54) after Ca-sCT in males and in 12 (0.80) compared to 11 (0.73) in females; without statistical significance. In patients with CCH or low tumor burden, there was a tendency of faster CT release after Ca stimulation (CT peak after 3min in > 60%) compared to patients with advanced MTC (CT peak after 3min in < 10%).

Conclusions

Using gender-specific cut-off values, Ca could replace Pg to predict MTC with similar diagnostic power.

Neuroendocrine Liver Metastasis-a Specific Set of Markers to Detect Primary Tumor Sites

The diagnosis of neuroendocrine neoplasia (NEN) is often made at an advanced stage of disease, including hepatic metastasis. At this point, the primary may still be unknown and sometimes cannot even be detected by functional imaging, especially in very small tumors of the pancreas (pan) and small intestinal (si) entities. The site of the primary may be based on biopsy specimens of the liver applying a specific set of markers. Specimens of liver metastases from 87 patients with NENs were studied. In retrospect, 50 patients had si and 37 pan NENs. Tissue samples were evaluated by immunohistochemistry. The markers applied were insulin gene enhancer protein Islet-1 (ISL-1), homeobox protein CDX-2 (CDX2), thyroid transcription factor 1 (TTF-1), and serotonin. Positive stains for CDX2 were documented in 43 (86%) and for serotonin in 45 (90%) of 50 siNENs. Three panNENs were positive for CDX2 and one for serotonin, respectively. ISL-1 was negative throughout in siNENs and also negative in 8 of 50 panNENs (21.6%). TTF-1 was negative in more than 90% of the specimens of either entity. Immunohistochemical markers in liver metastasis can lead the way to the site of the primary NEN. They should always be used in combined clusters.

Intertumor heterogeneity in 60 pancreatic neuroendocrine tumors associated with multiple endocrine neoplasia type 1

BACKGROUND

Patients with multiple endocrine neoplasia type 1 (MEN-1) develop multiple pancreatic neuroendocrine neoplasias (PNENs). Size at diagnosis and growth during follow-up are crucial parameters. According to the WHO 2017, grading is another important parameter. The impact of grading compared to size (WHO 2000) on the clinical course needs to be evaluated.

METHODS

Sixty PNENs of six patients with MEN-1 were retrospectively evaluated.

RESULTS

Fifty-one tumors with a diameter of < 20 mm were graded as G1. Two of 9 tumors with diameters of ≥20 mm were graded as G2. Tumor size of ≥20 mm correlated significantly with higher proliferation (p = 0.000617). Lymph node metastases were documented in two patients with a total of 19 tumors. In one patient, all 13 tumors (diameter: 0.4 to 100 mm) were classified as G1. However, metastases were documented in 9/29 lymph nodes. In the other patient, 5 tumors (3.5 to 20 mm) were classified as G1. The sixth tumor (30 mm) was classified as G2 (Ki-67: 8%). Metastases were revealed in 2/20 lymph nodes.

CONCLUSIONS

Tumor size of ≥20 mm seems to correlate with more aggressive MEN-1 related pancreatic disease, regardless of individual proliferation. Tumors ≥20 mm and tumors graded as G2 should be treated surgically regardless of their size.

Medullary Thyroid Carcinoma: Do Ultrasonography and F-DOPA-PET-CT Influence the Initial Surgical Strategy?

Background

At the time of diagnosis, one-third of medullary thyroid carcinoma (MTC) patients show lymph node (LN) or distant metastasis. A metastasized MTC requires different surgical strategies.

Objective

This study aimed to determine the value of ultrasound and [18F]fluoro-dihydroxyphenylalanine positron emission tomography with computed tomography (F-DOPA-PET-CT) in localizing MTC, as well as LN and distant metastasis.

Methods

The study included 50 patients (24 males/26 females) with preoperative ultrasound, F-DOPA-PET-CT, and histologically proven MTC. Imaging results were correlated with both preoperative basal calcitonin (bCt) levels and final histology.

Results

Tumors were classified as pT1a:17 (diameter, mean ± standard deviation: 5.8 ± 3.0 mm), pT1b:15 (15.0 ± 3.2 mm), pT2:9 (27.3 ± 7.0 mm), and pT3:9 (38.3 ± 24.2 mm). The median bCt level was 202 pg/mL (lower/upper quartile: 82/1074 pg/mL). Ultrasound was positive for tumor in 45/50 (92%) patients (20.0 ± 16.0 mm) and negative in 5 patients (3.2 ± 2.2 mm). Overall, 43/50 (86%) patients had positive F-DOPA local scans (20.0 ± 16.4 mm), while 7 (14%) patients were negative (7.7 ± 8.1 mm). Lastly, 21/50 (42%) patients had LN metastasis; 8/21 (38%) patients had positive LNs suspected with ultrasound, and 12/21 (57%) patients had positive LNs suspected with F-DOPA. Tumor and LN sensitivity of ultrasound was 92% and 43%, respectively, and 86% and 57% of F-DOPA-PET-CT, respectively. In 3/50 (6%) patients and 3/50 (6%) patients, mediastinal LN metastasis and distant metastasis, respectively, were diagnosed only by F-DOPA-PET-CT.

Conclusion

Ultrasound and F-DOPA-PET-CT are sensitive for the localization of MTC but not for the presence and location of LN metastasis (limitations: size/number). Only F-DOPA ensures the diagnosis of distant metastasis and influences the extent of LN surgery. Surgical strategy cannot be predicted based on neither ultrasound nor F-DOPA-PET-CT.

Analysis of 10 Adrenocortical Carcinoma Patients in the Cohort of the Precision Medicine Platform MONDTI

OBJECTIVE

Adrenocortical carcinoma (ACC) is a rare disease with a dismal prognosis. We aimed to evaluate if a personalized medicine approach may be useful for matching patients with ACC to targeted therapies.

METHODS

This is an analysis of 10 molecularly profiled ACCs that were progressing under standard of care treatment. The profile consisted of a 50-gene next-generation sequencing panel, immunohistochemistry (IHC), and fluorescence in situ hybridization for several proteins or chromosomal aberrations.

RESULTS

In 6 (60%) tumor samples, no somatic mutation was detected, while in 3 (30%) tumors 1 mutation was detected and in 1 (10%) tumor 2 mutations were detected. These mutations were CTNNB1 (2 samples), TP53 (1 sample), RB1 (1 sample) and APC (1 sample). Expression of phospho-mTOR and of EGFR was commonly detected by IHC (87.5 and 62.5%). In 4 (50%) samples, IHC revealed a weak expression of progesterone receptor. Less frequent alterations were expression of PDGFR-α, c-KIT, and estrogen receptor, each in 1 case.

CONCLUSIONS

Based on the molecular profile, no recommendation for targeted therapy was made by the multi-disciplinary team. Currently, ACC might not be suitable for a precision medicine approach according to our tests.

Colon cancer cell-derived 12(S)-HETE induces the retraction of cancer-associated fibroblast via MLC2, RHO/ROCK and Ca2+ signalling

Retraction of mesenchymal stromal cells supports the invasion of colorectal cancer cells (CRC) into the adjacent compartment. CRC-secreted 12(S)-HETE enhances the retraction of cancer-associated fibroblasts (CAFs) and therefore, 12(S)-HETE may enforce invasivity of CRC. Understanding the mechanisms of metastatic CRC is crucial for successful intervention. Therefore, we studied pro-invasive contributions of stromal cells in physiologically relevant three-dimensional in vitro assays consisting of CRC spheroids, CAFs, extracellular matrix and endothelial cells, as well as in reductionist models. In order to elucidate how CAFs support CRC invasion, tumour spheroid-induced CAF retraction and free intracellular Ca²⁺ levels were measured and pharmacological- or siRNA-based inhibition of selected signalling cascades was performed. CRC spheroids caused the retraction of CAFs, generating entry gates in the adjacent surrogate stroma. The responsible trigger factor 12(S)-HETE provoked a signal, which was transduced by PLC, IP3, free intracellular Ca²⁺, Ca²⁺-calmodulin-kinase-II, RHO/ROCK and MYLK which led to the activation of myosin light chain 2, and subsequent CAF mobility. RHO activity was observed downstream as well as upstream of Ca²⁺ release. Thus, Ca²⁺ signalling served as central signal amplifier. Treatment with the FDA-approved drugs carbamazepine, cinnarizine, nifedipine and bepridil HCl, which reportedly interfere with cellular calcium availability, inhibited CAF-retraction. The elucidation of signalling pathways and identification of approved inhibitory drugs warrant development of intervention strategies targeting tumour–stroma interaction.

32nd International Austrian Winter Symposium : Zell am See, the Netherlands. 20-23 January 2016

A1 68Ga-PSMA PET/CT in staging and restaging of Prostate Cancer Patients: comparative study with 18F-Choline PET/CT

W Langsteger, A Rezaee, W Loidl, HS Geinitz, F Fitz, M Steinmair, G Broinger, L Pallwien-Prettner, M Beheshti

A2 F18 Choline PET – CT: an accurate diagnostic tool for the detection of parathyroid adenoma?

L Imamovic, M Beheshti, G Rendl, D Hackl, O Tsybrovsky, M Steinmair, K Emmanuel, F Moinfar, C Pirich, W Langsteger

A3 [18F]Fluoro-DOPA-PET/CT in the primary diagnosis of medullary thyroid carcinoma

A Bytyqi, G Karanikas, M Mayerhöfer, O Koperek, B Niederle, M Hartenbach

A4 Variations of clinical PET/MR operations: An international survey on the clinical utilization of PET/MRI

T Beyer, K Herrmann, J Czernin

A5 Standard Dixon-based attenuation correction in combined PET/MRI: Reproducibility and the possibility of Lean body mass estimation

I Rausch, P Rust, MD DiFranco, M Lassen, A Stadlbauer, ME Mayerhöfer, M Hartenbach, M Hacker, T Beyer

A6 High resolution digital FDG PET/MRI imaging for assessment of ACL graft viability

K Binzel, R Magnussen, W Wei, MU Knopp, DC Flanigan, C Kaeding, MV Knopp

A7 Using pre-existing hematotoxicity as predictor for severe side effects and number of treatment cycles of Xofigo therapy

A Leisser, M Nejabat, M Hartenbach, G Kramer, M Krainer, M Hacker, A Haug

A8 QDOSE – comprehensive software solution for internal dose assessment

Wencke Lehnert, Karl Schmidt, Sharok Kimiaei, Marcus Bronzel, Andreas Kluge

A9 Clinical impact of Time-of-Flight on next-generation digital PET imaging of Yttrium-90 radioactivity following liver radioembolization

CL Wright, K Binzel, J Zhang, Evan Wuthrick, Piotr Maniawski, MV Knopp

A10 Snakes in patients! Lessons learned from programming active contours for automated organ segmentation

M Blaickner, E Rados, A Huber, M Dulovits, H Kulkarni, S Wiessalla, C Schuchardt, RP Baum, B Knäusl, D Georg

A11 Influence of a genetic polymorphism on brain uptake of the dual ABCB1/ABCG2 substrate [11C]tariquidar

M Bauer, B Wulkersdorfer, W Wadsak, C Philippe, H Haslacher, M Zeitlinger, O Langer

A12 Outcome prediction of temporal lobe epilepsy surgery from P-glycoprotein activity. Pooled analysis of (R)-[11C]-verapamil PET data from two European centres

M Bauer, M Feldmann, R Karch, W Wadsak, M Zeitlinger, MJ Koepp, M-C Asselin, E Pataraia, O Langer

A13 In-vitro and in-vivo characterization of [18F]FE@SNAP and derivatives for the visualization of the melanin concentrating hormone receptor 1

M Zeilinger, C Philippe, M Dumanic, F Pichler, J Pilz, M Hacker, W Wadsak, M Mitterhauser

A14 Reducing time in quality control leads to higher specific radioactivity of short-lived radiotracers

L Nics, B Steiner, M Hacker, M Mitterhauser, W Wadsak

A15 In vitro 11C-erlotinib binding experiments in cancer cell lines with epidermal growth factor receptor mutations

A Traxl, Thomas Wanek, Kushtrim Kryeziu, Severin Mairinger, Johann Stanek, Walter Berger, Claudia Kuntner, Oliver Langer

A16 7-[11C]methyl-6-bromopurine, a PET tracer to measure brain Mrp1 function: radiosynthesis and first PET evaluation in mice

S Mairinger, T Wanek, A Traxl, M Krohn, J Stanek, T Filip, M Sauberer, C Kuntner, J Pahnke, O Langer

A17 18F labeled azidoglucose derivatives as “click” agents for pretargeted PET imaging

D Svatunek, C Denk, M Wilkovitsch, T Wanek, T Filip, C Kuntner-Hannes, J Fröhlich, H Mikula

A18 Bioorthogonal tools for PET imaging: development of radiolabeled 1,2,4,5-Tetrazines

C Denk, D Svatunek, T Wanek, S Mairinger, J Stanek, T Filip, J Fröhlich, H Mikula, C Kuntner-Hannes

A19 Preclinical evaluation of [18F]FE@SUPPY- a new PET-tracer for oncology

T Balber, J Singer, J Fazekas, C Rami-Mark, N Berroterán-Infante, E Jensen-Jarolim, W Wadsak, M Hacker, H Viernstein, M Mitterhauser

A20 Investigation of Small [18F]-Fluoroalkylazides for Rapid Radiolabeling and In Vivo Click Chemistry

C Denk, D Svatunek, B Sohr, H Mikula, J Fröhlich, T Wanek, C Kuntner-Hannes, T Filip

A21 Microfluidic 68Ga-radiolabeling of PSMA-HBED-CC using a flow-through reactor

S Pfaff, C Philippe, M Mitterhauser, M Hartenbach, M Hacker, W Wadsak

A22 Influence of 24-nor-ursodeoxycholic acid on hepatic disposition of [18F]ciprofloxacin measured with positron emission tomography

T Wanek, E Halilbasic, M Visentin, S Mairinger, B Stieger, C Kuntner, M Trauner, O Langer

A23 Automated 18F-flumazenil production using chemically resistant disposable cassettes

P Lam, M Aistleitner, R Eichinger, C Artner

A24 Similarities and differences in the synthesis and quality control of 177Lu-DOTA-TATE, 177Lu -HA-DOTA-TATE and 177Lu-DOTA-PSMA (PSMA-617)

H Eidherr, C Vraka, A Haug, M Mitterhauser, L Nics, M Hartenbach, M Hacker, W Wadsak

A25 68Ga- and 177Lu-labelling of PSMA-617

H Kvaternik, R Müller, D Hausberger, C Zink, RM Aigner

A26 Radiolabelling of liposomes with 67Ga and biodistribution studies after administration by an aerosol inhalation system

U Cossío, M Asensio, A Montes, S Akhtar, Y te Welscher, R van Nostrum, V Gómez-Vallejo, J Llop

A27 Fully automated quantification of DaTscan SPECT: Integration of age and gender differences

F VandeVyver, T Barclay, N Lippens, M Troch

A28 Lesion-to-background ratio in co-registered 18F-FET PET/MR imaging – is it a valuable tool to differentiate between low grade and high grade brain tumor?

L Hehenwarter, B Egger, J Holzmannhofer, M Rodrigues-Radischat, C Pirich

A29 [11C]-methionine PET in gliomas - a retrospective data analysis of 166 patients

N Pötsch, I Rausch, D Wilhelm, M Weber, J Furtner, G Karanikas, A Wöhrer, M Mitterhauser, M Hacker, T Traub-Weidinger

A30 18F-Fluorocholine versus 18F-Fluorodeoxyglucose for PET/CT imaging in patients with relapsed or progressive multiple myeloma: a pilot study

T Cassou-Mounat, S Balogova, V Nataf, M Calzada, V Huchet, K Kerrou, J-Y Devaux, M Mohty, L Garderet, J-N Talbot

A31 Prognostic benefit of additional SPECT/CT in sentinel lymph node mapping of breast cancer patients

S Stanzel, G Pregartner, T Schwarz, V Bjelic-Radisic, B Liegl-Atzwanger, R Aigner

A32 Evaluation of diagnostic value of TOF-18F-FDG PET/CT in patients with suspected pancreatic cancer

S Stanzel, F Quehenberger, RM Aigner

A33 New quantification method for diagnosis of primary hyperpatahyroidism lesions and differential diagnosis vs thyropid nodular disease in dynamic scintigraphy

A Koljević Marković, Milica Janković, V Miler Jerković, M Paskaš, G Pupić, R Džodić, D Popović

A34 A rare case of diffuse pancreatic involvement in patient with merkel cell carcinoma detected by 18F-FDG

MC Fornito, D Familiari

A35 TSH-stimulated 18F-FDG PET/CT in the diagnosis of recurrent/metastatic radioiodine-negative differentiated thyroid carcinomas in patients with various thyroglobuline levels

P Koranda, H Polzerová, I Metelková, L Henzlová, R Formánek, E Buriánková, M Kamínek

A36 Breast Dose from lactation following I131 treatment

WH Thomson, C Lewis

A37 A new concept for performing SeHCAT studies with the gamma camera

WH Thomson, J O’Brien, G James, A Notghi

A38 Whole body F-18-FDG-PET and tuberculosis: sensitivity compared to x-ray-CT

H Huber, I Stelzmüller, R Wunn, M Mandl, F Fellner, B Lamprecht, M Gabriel

A39 Emerging role 18F-FDG PET-CT in the diagnosis and follow-up of the infection in heartware ventricular assist system (HVAD)

MC Fornito, G Leonardi

A40 Validation of Poisson resampling software

WH Thomson, J O’Brien, G James

A41 Protection of PET nuclear medicine personnel: problems in satisfying dose limit requirements

J Hudzietzová, J Sabol, M Fülöp

Multicenter Evaluation of a Novel Automated Rapid Detection System of BRAF Status in Formalin-Fixed, Paraffin-Embedded Tissues

The mutated BRAF oncogene represents a therapeutic target in malignant melanoma. Because BRAF mutations are also involved in the pathogenesis of other human malignancies, the use of specific BRAF inhibitors might also be extended to other diseases in the future. A prerequisite for the clinical application of BRAF inhibitors is the reliable detection of activating BRAF mutations in routine histopathological samples. In a multicenter approach, we evaluated a novel and fully automated PCR-based system (Idylla) capable of detecting BRAF V600 mutations in formalin-fixed, paraffin-embedded tissue within 90 minutes with high sensitivity. We analyzed a total of 436 samples with the Idylla system. Valid results were obtained in 421 cases (96.56%). Its performance was compared with conventional methods (pyrosequencing or Sanger sequencing). Concordant results were obtained in 406 cases (96.90%). Reanalysis of eight discordant samples by next-generation sequencing and/or pyrosequencing with newly extracted DNA and the BRAF RGQ Kit confirmed the Idylla result in seven cases, resulting in an overall agreement of 98.57%. In conclusion, the Idylla system is a highly reliable and sensitive platform for detection of BRAF V600 mutations in formalin-fixed, paraffin-embedded material, providing an efficient alternative to conventional diagnostic methods, particularly for routine diagnostics laboratories with limited experience in molecular pathology.

Clinical presentation in insulinoma predicts histopathological tumour characteristics

BACKGROUND

Insulinomas are rare neuroendocrine tumours (NETs) of the pancreas, characterized clinically by neuroglycopenic symptoms during periods of substrate deficiency. The gold standard test for diagnosing an insulinoma is a 72-h fast. However, the prognostic value of parameters in the standardized 72-h fast on histopathological tumour criteria and clinical presentation has not been examined.

METHODS

In thirty-three patients diagnosed with an insulinoma records, and data were investigated retrospectively. Histopathological tumour characteristics, including staging, grading and size, were reviewed. Grading was performed using Ki-67 index. Cut-off values for classical grading (G(clas)) were set at G1(clas) ≤ 2%, G2(clas) 3-20% & G3(clas) >20% and for modified grading (G(mod)) at G1(mod) <5%, G2(mod) 5-20% & G3(mod) >20%.

RESULTS

When G(mod) criteria were applied, the initial blood glucose was lower in GII/III(mod) patients compared to GI(mod) (2.8 ± 0.8 vs 3.8 ± 1.3 mmol/l; P = 0.046). Basal and end of fast levels of insulin (basal insulin 71 ± 61 vs 20 ± 16 mU/l; P < 0.001; end of fast insulin 77 ± 51 vs 21 ± 20 mU/l; P < 0.001) and c-peptide (basal c-peptide 5.4 ± 2.4 vs 2.7 ± 1.6 μg/l; P = 0.004; end of fast c-peptide 5.3 ± 2.4 vs 2.5 ± 1.4 μg/l; P = 0.001) were significantly higher in GII/III(mod) than in GI(mod). No differences between the groups were observed when G(clas) criteria were applied. Additionally, close correlations were observed between insulin concentration, Ki-67 index and tumour size.

CONCLUSION

This study shows an impact of histopathological tumour characteristics in patients suffering from an insulinoma on clinical presentation during a standardized 72-h fast. Lower initial blood glucose levels and higher concentrations of insulin and c-peptide are associated with worse tumour grading and larger tumour size.

11C-methionine PET/CT imaging of 99mTc-MIBI-SPECT/CT-negative patients with primary hyperparathyroidism and previous neck surgery

CONTEXT

(99m)Tc-Methoxy-isobutyl-isonitrile (MIBI) scintigraphy is a standard preoperative localization imaging modality in patients with primary hyperparathyroidism (pHPT). Its accuracy in localizing a hyperactive parathyroid gland after previous cervical surgery is limited. Recently, (11)C-methionine has been introduced as a promising radiotracer for pHPT imaging. Yet, few data exist for this technique in patients with persisting or recurrent pHPT before reoperation.

OBJECTIVES

We aimed to investigate the ability of (11)C-methionine positron emission tomography (PET)/computed tomography (CT) to localize a parathyroid disorder after cervical surgery and negative postsurgical (99m)Tc-MIBI single-photon emission CT (SPECT)/CT.

DESIGN, SETTING, AND PARTICIPANTS

Fifteen patients (6 males, 9 females; age range, 36-85 years) with pHPT and negative (99m)Tc-MIBI SPECT/CT who had undergone earlier neck surgery because of pHPT and/or thyroid disorder were recruited. Twelve of the 15 patients had thyroidectomy for goiter or differentiated thyroid carcinoma. Ten patients had previous parathyroid surgery for pHPT, and 2 patients had a history of parathyroid carcinoma. Thirteen of 15 patients showed elevated levels of intact PTH at the time of PET/CT imaging, whereas all patients had elevated serum calcium values.

MAIN OUTCOME MEASUREMENTS

Pathological results of contrast-enhanced (11)C-methionine PET/CT and surgical results were evaluated.

RESULTS

In 6 of 15 patients (11)C-methionine PET/CT showed a hypermetabolic focus in the upper mediastinum in 2 patients, in the thoracic outlet in 1 patient, and in the cervical region in 3 patients. In 9 of the 15 patients, no hyperactive parathyroid gland could be visualized. Reoperation was performed in 5 of 6 patients without surgical complications. One patient refused surgery. In 2 of the 5 patients, a transsternal procedure was performed. Correlating with the (11)C-methionine PET/CT results, a single parathyroid adenoma was found in 4 patients and parathyroid carcinoma metastasis in 1 patient.

CONCLUSION

(11)C-Methionine PET/CT is a useful complementary imaging technique to localize parathyroid adenoma or carcinoma in (99m)Tc-MIBI SPECT/CT-negative patients.

Phosphorylation of STAT3 correlates with HER2 status, but not with survival in pancreatic ductal adenocarcinoma

Activation of signal-transcriptional factor signal transducer and activator of transcription 3 (STAT3) is associated with more aggressive behaviour in a variety of human malignancies. As selective STAT3 inhibitors exist, this protein might represent a novel therapeutic target. Although STAT3 seems to play an important role in progression of pancreatic ductal carcinoma (PDAC), only few data on this subject exist. The aim of our study was the investigation of STAT3 activation and its correlation with its possible regulator HER2. Expression of tyrosine-705 phosphorylated STAT3 (pSTAT3) was determined immunohistochemically in 79 PDACs. HER2 status assessed by immunohistochemistry and double colour silver in situ hybridization was available from a previous study. PSTAT3 expression was seen in 33 (41.8%) patients. Six patients were scored as HER2 positive having strong correlation with pSTAT3 expression (p = 0.004, Fisher's exact test). No association of pSTAT3 expression with patients' age, tumour staging and grading, perineural invasion of tumour cells or survival time was seen. pSTAT3 is frequently expressed in PDAC. Nevertheless, its immediate clinical relevance seems to be low. However, further research needs to determine whether STAT3 status in PDAC is predictive for the response to novel targeting therapies.

Diagnostic terminology for reporting thyroid fine needle aspiration cytology: European Federation of Cytology Societies thyroid working party symposium, Lisbon 2009

A European Federation of Cytology Societies (EFCS) working party of 28 members from 14 European countries met at the European Congress of Cytology in Lisbon in September 2009, with two observers from the USA, to discuss the need for standardising thyroid FNA nomenclature in the light of the National Institute of Cancer (NCI) recommendations resulting from the State of the Science conference in Bethesda in 2007. The data were obtained through two questionnaires sent by email and a transcript of the live discussion at the congress, which is presented in full. The surveys and discussion showed that there were currently no national terminologies for reporting thyroid FNA in the different European countries except in Italy and the UK. Personal, 'local', surgical pathology and descriptive terminologies were in use. All but one of the working party members agreed that thyroid FNA reporting should be standardised. Whilst almost a third would adopt the NCI Bethesda terminology, which offers the advantages of a 'risk of cancer' correlation and is linked to clinical recommendations, more than half favoured a translation of local terminology as the first step towards a unified nomenclature, as has been done recently in the UK. There was some disagreement about the use of: a) the six-tiered as opposed to four or five-tiered systems, b) the use of an indeterminate category and c) the 'follicular neoplasm' category, which was felt by some participants not to be different from the 'suspicious of malignancy' category. The conclusions will be passed to the different national societies of cytology for discussion, who will be asked to map their local terminologies to the Bethesda classification, observe its acceptance by clinicians and audit its correlation with outcome.

Primary central nervous system lymphoma: a clinicopathological study of 75 cases

AIMS

Pathological and clinical data in a large series of immunocompetent patients with primary lymphoma of the central nervous system (PCNSL) were analysed.

METHODS

We immunostained tumour specimens of 75 patients for CD3, CD4, CD5, CD8, CD10, CD20, CD30, CD79a, Bcl-2, Bcl-6, CD138, MUM1, TDT, PAX5, FOXP1 and Ki-67 and performed in situ hybridisation for Epstein-Barr virus (EBV) RNA. Eleven cases were investigated for rearrangements of BCL6, immunoglobulin heavy chain (IGH) and FOXP1 genes using fluorescent in situ hybridisation (FISH).

RESULTS

Histologically, most cases were classified as diffuse large B-cell lymphoma (80.2%) predominantly of centroblastic type. Immunophenotypic profiling revealed that 96% and 4% of cases corresponded to non-germinal centre and germinal centre type, respectively. FISH analysis showed t(3;14)/IGH-BCL6 in 2/11 cases and trisomy 3 in 2/11 cases. FOXP1 rearrangements were not found. At survival analysis, Karnofsky index >80 and presence of Bcl-6 expression showed independent significant association with favourable patient outcome.

CONCLUSIONS

PCNSL represents a histologically and immunophenotypically very homogeneous lymphoma type, probably derived from germinal centre exit B cells. The frequent overexpression of FOXP1 appears not to be related to FOXP1 gene rearrangement. Survival analyses disclosed Bcl-6 expression and high Karnofsky performance score as independent prognostic parameters associated with favourable outcome.

Higher frequency of thyroid tumors in the right lobe

Recently, using ultrasonography, we observed that the right lobe usually is larger compared with the left thyroid lobe. Since the higher cell number in a larger right lobe may confer a higher tumor risk, we investigated the location of benign and malignant lesions to test the hypothesis of a more frequent occurrence in this lobe. In 1,001 consecutive patients with benign thyroid lesions, tumors more frequently occurred in the right lobe (+21.5%, p = 0.0022). Furthermore, in 1,277 thyroid cancer patients with 1,302 thyroid cancers, the right lobe more often harbored the tumor initially (+22.9%, p = 0.0009). Our data show a larger proportion of both benign and malignant tumors in the right thyroid lobe.

High efficacy of concomitant treatment of undifferentiated (anaplastic) thyroid cancer with radiation and docetaxel

CONTEXT

Anaplastic thyroid carcinoma (ATC) is a rare but aggressive solid tumor with a very short survival time even with multimodality treatment. In view of in vitro data and the high rate of p53 mutations in ATC, we have used combined treatment with external beam radiation and docetaxel.

OBJECTIVE

The objective was to analyze the activity using radiation plus docetaxel.

DESIGN

The design was a retrospective analysis.

SETTING

The study was performed in a referral center of a university hospital.

PATIENTS

A total of six patients with ATC were treated at our institution.

INTERVENTION

Treatment consisted of standard external beam radiation of 60.0 Gy in 30 fractions along with docetaxel at a flat dose of 100 mg absolute every 3 wk for a total of six cycles starting within the first week of radiation.

OUTCOME MEASURE

The outcome measure included clinical response and survival.

RESULTS

Five patients completed radiochemotherapy. One patient has completed radiation but is still on treatment with docetaxel. Four patients achieved complete remission and two partial response. During radiation therapy, four patients developed severe mucositis/stomatitis and two dermatitis, necessitating hospitalization. Two patients developed pneumonia and one urinary tract infection. All patients were hospitalized for a median of 17 d (range, 4-40 d) because of toxicites. After a median follow up of 21.5 months (range, 2-40 months), five patients are alive.

CONCLUSION

The preliminary data suggest that the combination of radiation and concomitant docetaxel is highly effective in patients with ATC. However, a formal phase II study is needed to assess the therapeutic potential of this combination.

Indeterminate thyroid nodules: a challenge for the surgical strategy

BACKGROUND

Because no clinical parameter can establish the final status of a cytologically indeterminate thyroid nodule (ITN) or nodal-metastases in case of malignancy, the initial surgical strategy should define an oncologically adequate procedure with low morbidity.

METHODS

The prognostic relevance of sex, age, tumor sizes, multifocality, thyroid function, and recurrence was analyzed in 156 consecutive patients according to the presence of malignancy and nodal metastases. The accuracy of frozen sections to reveal malignancy was determined. Clinical parameters were compared with regard to their ability to identify malignancy and nodal metastases in an ITN to determine an appropriate initial operative strategy.

RESULTS

One hundred and eighteen (75.6%) patients underwent (total) thyroidectomy, 37 (23.7%) patients underwent hemithyroidectomy, and 1 patient underwent isthmus resection. Fifty-five (35.3%) patients showed malignancy. First step lymphadenectomy (lymph node dissection along the recurrent laryngeal nerve before removing the thyroid lobe) was performed in 142 patients documenting 10 nodal metastases. Comparing benign and malignant ITN, no association was found for sex (P = .17), age (P = 1.0), tumor sizes (P = .33, P = .12, P = .19 for < or =30 mm, < or =40 mm, and < or =50 mm, respectively), or thyroid function (P = .26). The determination of malignancy by frozen section showed a sensitivity of 30.9% and a specificity of 100%. No permanent hypoparathyroidism or recurrent laryngeal nerve palsy was observed postoperatively.

CONCLUSION

Because of the failure of available clinical parameters to predict malignancy in cytologically ITN, hemithyroidectomy in unilateral goiter and thyroidectomy in bilateral goiter is recommended. Ipsilateral "first step central neck dissection" on the side of ITN offers the advantages of oncologically adequate resection and staging with a low morbidity, as well as avoids reoperation.

Tenascin C in medullary thyroid microcarcinoma and C-cell hyperplasia

Tenascin C (Tn-C) is an extracellular matrix glycoprotein that is expressed early in carcinogenesis including intraepithelial neoplastic lesions of different organs. In this study, we analyze whether stroma reaction seen by Tn-C expression is detected early in tumorigenesis of medullary thyroid carcinoma (MTC) including medullary microcarcinoma and C-cell hyperplasia (CCH), which is accepted to be a precursor lesion of MTC in the setting of RET oncogene germ-line mutation. Tn-C was expressed in the stroma of all medullary microcarcinoma and in the stroma next to CCH. Stromal Tn-C expression was significantly more often seen in CCH with concomitant MTC than in isolated CCH of hereditary as well as nonhereditary cases (p = 0.001 and p = 0.016, respectively). We conclude that Tn-C expression and thus early stroma remodeling is seen in medullary microcarcinoma and CCH. Stromal Tn-C expression seems to be an indicator of a further step in carcinogenesis of MTC irrespective of a RET oncogene germ-line mutation.

Desmoplasia in medullary thyroid carcinoma: a reliable indicator of metastatic potential

AIMS

To evaluate the reliability of desmoplasia as a reproducible morphological parameter indicating the metastatic potential of medullary thyroid carcinoma (MTC).

METHODS AND RESULTS

One hundred and twenty cases of MTC of the Medical University of Vienna, Austria and 76 cases from the School of Medicine of Marseille, France were analysed for the presence of desmoplastic stroma reaction by four endocrine pathologists. Intra- and interobserver concordance was assessed. The Austrian cases were also analysed for various morphological parameters. Intra- and interobserver concordance were highly significant with a kappa value of 0.883 for intra-observer reliability and 0.837, 0.79 and 0.758, respectively, when pathologists N.N., C.D.M. and K.W.S. reviewed the Austrian cases. The cases from France were reviewed by C.D.M. and K.K. with a kappa value of 0.759. None of the cases that were categorized as desmoplasia negative by any of the investigators showed lymph node metastasis. No other distinct morphological characteristics could be assigned to the MTCs without desmoplasia.

CONCLUSIONS

Our data indicate desmoplasia to be a reliable and highly reproducible parameter with regard to lymph node metastatic potential.

Molecular characterization of the desmoplastic tumor stroma in medullary thyroid carcinoma

Medullary thyroid carcinomas are aggressive neoplasias that metastasize very early to loco-regional lymph nodes, and tumors with a desmoplastic stromal reaction have a higher incidence of lymph node metastasis. In order to characterize the desmoplastic response in thyroid cancers, we evaluated the expression pattern of three molecular markers of activated fibroblasts/myofibroblasts, namely, fibroblast activation protein alpha (FAPalpha), tenascin-C (Tn-C), and alpha-smooth muscle actin (alpha-SMA), as well as the endothelial markers endoglyx-1, CD34 and CD31 in a series of 28 metastatic and non-metastatic medullary thyroid cancers. Immunohistochemical studies demonstrated that the three fibroblast activation markers (FAPalpha, Tn-C, alpha-SMA) are consistently expressed in the peritumoral and intratumoral stromal compartment of medullary thyroid carcinomas and expression of FAPalpha and Tn-C correlated with the degree of desmoplasia determined histologically (p=0.001 for FAPalpha and p<0.001 for Tn-C). Moreover, the extent of desmoplasia as well as the expression of FAPalpha and Tn-C correlated with the presence of lymph node (LN) metastases (p=0.002, p=0.005 and p=0.002, respectively). No correlation was found between the microvessel density (neoangiogenesis) in the tumor stroma, assessed with the endoglyx-1, CD34 and CD31 markers, and the degree of desmoplasia or incidence of LN metastases. Using a bioinformatics-based search of the BioExpresstrade mark database we found in a series of 48 thyroid cancers a significant correlation between FAPalpha RNA expression and incidence of LN metastases also in papillary cancers. These findings suggest that the link between specific molecular markers of tumor stromal reaction and locoregional metastasis extends from medullary to other thyroid cancer types.

Prion disease with a 144 base pair insertion: unusual cerebellar prion protein immunoreactivity

Sporadic, acquired, and genetic human prion diseases are characterized neuropathologically by distinct deposition patterns of the abnormal, disease-associated form of the prion protein (PrP(sc)). In addition to mutations in the prion protein gene (PRNP), PrP(sc) immunostaining patterns correlate with molecular phenotypes of prion diseases defined by the PRNP polymorphism at codon 129 and with protease-resistant PrP classified by Western blotting. Some point or insertional PRNP mutations share similar clinical and neuropathological phenotypes, whereas others show great variability even within the same family. Here we report a patient who presented clinically as sporadic Creutzfeldt-Jakob disease (CJD). Histologically moderate spongiform change was seen in cerebral and cerebellar cortical areas. Neuronal loss was restricted mainly to the occipital cortex and the basal ganglia. Surprisingly, numerous eosinophilic globular structures were noted in the molecular layer and the parahippocampal gyrus. These globules showed intense PrP immunopositivity using anti-PrP antibodies against different epitopes. They were stained with PAS but lacked congophilia and birefringence in polarized light. Ultrastructurally, globules were composed of 21-nm-thick intermingled filaments without dense core. Genetic analysis revealed a PRNP 144 base pair insertion. Our case reinforces the importance of molecular genetic diagnosis, especially in those patients who lack a family history of prion disease and show unusual neuropathological changes. It also widens the phenotypic spectrum of prion diseases. The phenotypic variability within the same mutation suggests further, yet uncharacterized, genetic or epigenetic influence on phenotype in these diseases.

Intraventricular meningiomas: a report of 16 cases

Meningiomas of the ventricle system are extremely rare. We report on a series of 16 intraventricular meningiomas (IVMs) treated at our institution between 1980 and 2004, with a special interest on the surgical outcome of using the intra/inter-parietal and parieto-occipital approach and the benefits of neuro-navigation. A retrospective analysis of the medical files for clinicoradiological findings, surgical interventions and surgical outcome was carried out. In 16 IVM patients with a female/male ratio of 11:5, age ranged from 24 years to 84 years (median 44 years). Duration of symptoms ranged from a few days to several years, and the cardinal symptoms were signs of increased intracranial pressure (86%), followed by corticospinal tract signs (43%), visual field defects (36%), cognitive changes (29%) and seizures (7%). The majority of tumours was located in the trigone (88%), and one was found in each the temporal horn and in the fourth ventricle. Tumour size ranged from 2.5 cm to 8 cm (median 5 cm), and the radiological appearance was uniform. The neuropathological workup revealed most IVMs as meningothelial, transitional (mixed) or lymphoplasmacyte-rich meningiomas (81%). Three tumours were classified as atypical (19%) and the MIB-1 proliferation index ranged from 1% to 40%. Complete resection was possible in all but one case. The trigonal IVMs were resected via an intraparietal/inter-parietal or parieto-occipital approach, and neuro-navigation was used in eight tumours. We encountered one perioperative death and one severely disabled patient. All other patients had a Glasgow outcome scale score of 5, and most of the pre-existing symptoms disappeared or improved after surgery. IVMs are a surgically curable tumour entity in most cases. The intraparietal/inter-parietal and parieto-occipital approach is very safe, and neuro-navigation allows early devascularisation of the tumour.

Recurrent central neurocytomas

BACKGROUND

Since the first description of Central neurocytomas (CNs) as a benign tumor entity in 1982, there has been great enthusiasm regarding the benign course and the curative surgical approach to this disease. The current study was performed to investigate the frequency of disease recurrence during long-term follow-up.

METHODS

A retrospective analysis of the medical files with emphasis on clinicoradiologic findings and histologic and immunohistochemical features was performed.

RESULTS

Between 1985-2003. surgical resection was performed in 14 patients with CNs ages 16-43 years (7 were female and 7 were male). Two patients (14%) died postoperatively and one patient had a malignant disease course (7%). In the remaining 11 patients, one patient with an incompletely resected CN had disease progression after 37 months but at the time of last follow-up had had stable disease for 10 years. In addition, the authors reported 5 patients with disease recurrence occurring at a median of 67 months after surgery (range, 51-79 months after surgery), all of which occurred after complete surgical resection was performed. The observation period for the remaining 5 patients was short (median of 34 months [range, 5-44 months]). Extensive histologic and immunohistochemical workup did not identify any significant prognostic parameters. The MIB-1 proliferation index ranged from 0.8-11% (median of 4.6%), but was reported to be 46.8% in the malignant transformed tumor. All patients with disease recurrence responded well to different forms of focal radiation therapy (gamma knife radiosurgery in three patients and interstitial irradiation in one patient) and for one patient with a recently detected recurrence, gamma knife radiosurgery was planned.

CONCLUSIONS

CNs appear to have a higher tendency to recur during long-term follow-up than previously reported, even after complete resection. Therefore, periodic neuroradiologic follow-up examinations should be considered mandatory in all patients, even after several years.

Value and limits of immunohistochemistry in differential diagnosis of clear cell primary brain tumors

Clear cell histology is the hallmark of oligodendroglioma (OG) but also characterizes clear cell ependymoma (CCE) and central neurocytoma (CN). Immunohistochemistry for glial and neuronal proteins may support differential diagnosis. We investigated systematically diagnostic value and limits of immunohistochemistry using representative tumor specimens (>1 cm in diameter) of well-defined OGs, CCEs, and CNs (n=10, respectively). Antibodies comprised anti-neuron specific nuclear protein (NEUN), anti-synaptophysin, anti-neuron-specific enolase, anti-microtubule-associated protein 2, anti-phosphorylated neurofilament protein, anti-non-phosphorylated neurofilament protein, anti-glial fibrillary acidic protein (GFAP), anti-S100 protein, anti-vimentin (VIM), and anti-epithelial membrane antigen (EMA). Among the panel of antibodies anti-NEUN, anti-VIM and anti-EMA proved most useful for differential diagnosis. Prominent (>90%) anti-NEUN immunolabeling of tumor cells clearly distinguished CNs from OGs and CCEs. Anti-VIM immunolabeling and a characteristic cytoplasmic dot-like anti-EMA immunoreactivity pattern of tumor cells were detectable only in OGs and CCEs. Furthermore, prominent anti-VIM immunoreactivity and anti-EMA cell membrane staining including ring-like staining pattern is characteristic for CCEs. Additionally, a widespread gliofibrillary and minigemistocytic cytoplasmic anti-GFAP immunostaining pattern is restricted to some OGs. Our data indicate that immunohistochemistry using anti-NEUN, anti-VIM, and anti-EMA on representative tumor specimens allows clear-cut distinction of CNs vs OGs and CCEs. Anti-VIM, anti-EMA, and anti-GFAP support differential diagnosis of OGs vs CCEs. Nevertheless, it is noted that due to focal expression of glial proteins in CNs and, conversely, of neuronal proteins in OGs and CCEs, immunohistochemistry is of limited value on small tumor specimens.

Disease-associated prion protein in vessel walls

Human prion diseases like Creutzfeldt-Jakob disease are infectious, inherited, or sporadic neurodegenerative disorders, characterized by the accumulation of an abnormal isoform of the host-encoded prion protein. This affects nervous tissue in sporadic Creutzfeldt-Jakob disease and, additionally, in lymphoid tissue in bovine spongiform encephalopathy-linked variant Creutzfeldt-Jakob disease. Experimental studies have established the involvement of cells of the lymphoid and peripheral nervous system in the transport of prions to their target central nervous system tissue. To evaluate the role of vessel wall-associated mobile cells, we obtained formalin-fixed tissue blocks from various brain regions and/or basal arteries from sporadic, variant and iatrogenic Creutzfeldt-Jakob disease, and unselected control cases. We demonstrate disease-associated prion protein deposits in intracranial vessel walls, in sporadic and variant Creutzfeldt-Jakob disease by performing immunohistochemical staining and paraffin-embedded tissue blotting. Using double immunofluorescence, these deposits co-localize with HLA-DR and S-100 immunoreactive cells in the intima, which are components of the vascular-associated dendritic cell network, as well as with HLA-DR and CD-68 immunopositive macrophages of the intima and media. We conclude that mobile cells in vessel walls like dendritic and monocyte/macrophage lineage cells may be involved in spread of disease-associated prion protein and possibly also of infectivity.