Aim: We present an unusual case of malignant gastrointestinal stromal tumor filling the entire abdominal cavity. Introduction: Gastrointestinal stromal tumors are the most common mesenchymal neoplasms of the gastrointestinal tract. Small tumors are generally benign, but large tumors disseminate to the liver, omentum and peritoneal cavity. They rarely occur in other abdominal organs. Material and Metods: The operative material consisted of segment of ileum where a tumor mass of 8 cm was found originating from the wall and fragments of small intestinal serosa and omentum where multiple nodular tumor mases were found. Representative samples were taken, and were paraffin embedded and stained routinely with Hematoxyllin-Eosin. Additionally immunohistochemical analyses were performed using the antibodies c-kit, CD34, Vimentin, CKAE1/AE3, Ki67 and others. Results: Microscopic analysis revealed a malignant gastrointestinal stromal tumor with a high mitotic rate of 58/50 HPF mitoses. However clinical reports stated that an additional large 12 cm tumor mass was found in the liver that was not removed. Conclusion: Gastrointestinal stromal tumors are the most common gastrointestinal mesenchymal neoplasms but presence of multiple tumor masses on various organs and sites is rare. Presence of multiple tumors in various organs brings about the issues of possibility of multiple primaries or the proper detection of the original tumor mass.

Aim: Evaluation of the usefulness of flow cytometry (FCM) serous effusion analysis in a diagnosis of pediatric Non-Hodgkin lymphomas (NHL). Introduction: Serous effusions are often the first, life-threatening manifestation of pediatric NHL. FCM immunophenotyping of effusions with cytological analysis could help in diagnosis of NHL, and thus enable fast initiating of cytoreductive therapy. Material and Methods: FCM analysis of serous effusions obtained from 17 children and adolescents hospitalized in Mother and Child Healthcare Institute of Serbia under clinical suspicion of NHL using the standardized panel of monoclonal antibodies: CD19, iCD79a, CD20, CD10, iIgM, kappa/lambda, iCD3, sCD3, CD7, CD2, CD5, CD4, CD8, CD1a. Cytological examination was performed on May-Grunwald-Giemsa stained slides. The results were correlated with histopathological findings of available tumor biopsies. Results: Precursor T-cell (T-III/T-IV) phenotype was confirmed in 5 samples. In 7/9 samples with mature B (B-IV) phenotype, FAB L3 cytomorphology indicated Burkitt lymphoma (BL), and in 2/8 suggested diffuse large B-cell lymphoma (DLBCL). Tumor biopsy was available in 7/14 patients and in all cases preliminary diagnosis was confirmed. In 3 patients with no malignant cells in effusions, FCM and cytomorphologicaly only reactive changes were observed, and diagnosis had to be made by tumor biopsy (BL 2 patients, DLBCL 1 patient). Out of 7 patients diagnosed only by FCM and cytological analysis, 6 achieved a remission of the illness. Conclusion: FCM detects NHL cells in malignant serous effusions fast and accurate. In combination with cytological analysis, FCM is sufficient for diagnosis in most cases, allowing rapid initiation of therapy.

Aim: We present a rare case of simultaneous occurrence Concurrent occurrence of acute myeloid leukemia (AML) and monoclonal plasmacitosis (MP): Introduction: The simultaneous occurrence of acute myeloid leukemia (AML) and monoclonal plasmacytosis (MP) in bone marrow (BM) biopsy in patient without previous exposure to chemotherapy is very rare. Case report: We reported the case of a 45-year-old woman who presented with fatigue, fever, maculopapular rush, weight loss and bone pain. She was admitted to the Haematology Department of University CHC Bezanijska Kosa in November 2015. The complete blood count showed: white blood cell count 33x109/l (neutrophils 31%, myeloblasts 12%, monoblasts, promonocytes and monocytes 53%), hemoglobin 77gr/l, platelet count 34x109/l and 5% blastic cells in the peripheral smear. Serum immunoelectrophoresis showed increased monoclonal IgA (IgA 9,98, IgM 2,29, IgG 10,1), kappa/lambda 0,84, Beta2microglobulin 3,16. Biochemistry showed elevated creatinin level 93umol/l, uric acid 412 umol/l, high LDH 876U/l and sedimentation rate (50mm/h). Urine electrophoresis showed monoclonal heavy and light chains lambda type. Liquor immunophenotyping showed neuroleukemia. Skeletal survey showed no lytic lesions. The BM aspiration revealed around 10% plasma cells and BM biopsy showed infiltration by 20% monoclonal plasma cells (kappa-/lambda ) with 30% infiltration by cells with monocytes differentiation (without excess of blasts). Biopsy of skin lesion 17 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. revealed myeloid sarcoma. Cytogenetic analysis detected normal karyiotype with FLT3 and NPM mutation. The patient was diagnosed as AML-M5, administered with induction therapy (DA Cytosar) and consolidation therapy (HiDAC) and she was successfully treated with allogenenic stem cell transplantation. She achieved and maintained complete remission. Conclusion: Monoclonal plasmacytosis of BM should be carefully examined due to possible association with other haematological malignancies

Aim: The aim of the study is to classify tumors into four main molecular subtypes using immunohistochemistry and in situ hybridisation methods, as well as to determine frequency of different carcinoma subtypes. Introduction: Four molecular subtypes of breast carcinoma can be identified: Luminal A and Luminal B (hormone receptors positive), HER2 enriched (HER2 overexpression) and Triple Negative / Basal-like (absence of HER2 amplification and steroid receptors expression). Materials and Methods: Cross-sectional study, conducted in Institute of pathology, Medical Faculty, University in Belgrade, during the ten months period in 2017, included 337 patients with diagnosed breast carcinoma. Using the methods of immunohistochemistry, all four markers (estrogen, progesteron, HER2, and Ki67) were evaluated on breast carcinoma tissues. As additional methods, “in situ” hybridisation (FISH, SISH) was used in cases if HER2 oncoprotein results on immunohistochemistry were equivocal. Results: Luminal A, Luminal B, HER2 enriched, and Triple Negative carcinomas were present in 133 (39,45%), 147 (43,62%), 22 (6,5%), 34 (10,08%) cases, respectively. For 55 (16,35%) cases, in situ hybridisation had been done in order to classify carcinomas in proper molecular subtype. Conclusion: Frequency of molecular subtypes of breast carcinomas in our study are similar to literature data for European countries. Breast carcinoma subtyping has prognostic and predictive values for further patient treatment, and should be done in institutions with adequately trained personnel and equipment, in order to achive best results in the shortest time.

The fourth Edition of the World Health Organization’s Classification of Tumours of Endocrine Organs from 2017 introduced some novelties based primarily on genetic research, compared to the previous edition from 2004. The most common primary tumors of the adrenal cortex are adenomas, and of the adrenal medulla are pheochromocytomas. As such, these tumors have their specificities in pathohistological diagnosis, by which they differentiate from tumors of other localizations. In the daily work of the pathologist dealing with the diagnosis of the tumor of the adrenal gland, differential diagnostic problems can occur, where biological behavior of the tumor cannot be predicted based on its morphological appearance; this primarily refers to cortical neoplasms and phaeochromocytomas. Scoring systems are used in these cases, Weiss and Lin-Weiss-Bisceglia criteria for cortical neoplasms, and PASS criteria for pheochromocytomas, where by recognizing the suggested morphological parameters, value or score is obtained which predicts the biological behavior of the tumor, i.e. differentiates benign from malignant neoplasms. The accepted algorithm of diagnostics of adrenocortical neoplasms also includes immunohistochemical staining for ki-67, which potentially can differentiate adrenocortical adenoma from carcinoma. Despite the introduction of these scoring systems, the only safe indicator of malignancy is still distant metastasis.

Pancreatic cancer is high aggressive malignant neoplasm with very poor prognosis and about only 5% a five-year survival. It is the fourth leading cause of cancer death in USA, as well in Serbia, although in terms of the incidence of this disease the mortality is rising and it takes seventh place. Speaking about the southern Backa, the mortality rate is slightly lower and it is the fifth place, according to the available literature. This can be explained by the lack of highly specific and sensitive diagnostic tests, which makes pancreatic cancer most often detected by an advanced, inoperable stage of the disease (>60%), although surgical resection is the only curative therapy. Analogous to other carcinomas, there is a gradual progression of the pancreatic duct epithelial cells, so every invasive carcinoma arises from the previous intraepithelial neoplasia. There are three different types of common precancerous lesions known for pancreatic cancer which clinical detection and treatment can stop the progression to invasive cancer and reduce mortality. The first one is Pancreatic Intraepithelial Neoplasia (PanIN), and the other two types of precancerous lesions are both larger fluid-filled types- Intraductal Papillary Mucinous Neoplasms (IPMNs) and Mucinous Cystic Neoplasms (MCNs). PanIN is an asymptomatic, small (usually <5 mm in diameter), nonfluid flat or papillary lesion arising in the small intralobular pancreatic ducts. It is the most common and important precursor of invasive pancreatic carcinoma. Histologically, it’s consisted of columnar to cuboidal cells with varying amounts of mucin. Accordingly to different degrees of cytological and architectural atypia, PanIN is classified into three grades- low, intermediate and high grade. PanIN-1A (flat) and PanIN-1B (papillary) are low grade lesions with minimal atypia, while PanIN-2 belongs to intermediate lesion showing mild to moderate atypia with frequent papillae. PanIN-3, also referred as “carcinoma in situ”, is characterized by severe cytological and architectural atypia amd it can be flat, papillary or cribriform pattern. The immunohistochemical profile of PanINs vary with the grade of dysplasia. Low grade lesions show positivity for gastric foveolar mucin MUC5AC, pyloric gland mucin MUC6, while MUC1 is almost exclusively expressed by high grade PanINs lesions. Among fluid-filled types of precancerous pancreatic lesions, IPMNs are the most common lesions. IPMNs vary in their location and size within the pancreas size, and these two features correlate with how dangerous they are. Because they can be detected by imaging procedures, it is possible to detect them before they become cancer. They are most often detected in patients who are routinely monitored due to a high familial risk, or incidentally in people who were imaged for another reason. Those lesions belong to group of the heterogeneous group of cystic pancreatic lesions because papillary epithelial proliferation and mucin production lead to cystic dilatation of involved ducts. SPECIJALNA SESIJA: KATEDRA ZA PATOLOGIJU MEDICINSKOG FAKULTETA, UNIVERZITETA NOVI SAD, SRBIJA 29 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. Those lesions are slightly more common in the head and uncinate process (55%) compared with the body and the tail of the pancreas and about 30% of them are multifocal. IPMNs are subdivided into main duct IPMN (MD-IPMN) which are localized in the main pancreatic duct and measured ≥5 mm, while the other branch duct type (BD-IPMN) is >5 mm in diameter andcommunicates with the main pancreatic duct but it is uninvolved by the process. Mixed IPMN combines both types. Microscopically, the lining epithelial component is represented by tall mucin producing columnar cells but lack the “ovarian-type” seen in mucinous cystic neoplasms. Like PanINs, IPMNs are graded on the basis of the greatest degree of dysplasia into low grade, moderate and high grade dysplasia or carcinoma in situ and IPMN with associated invasive carcinoma. Many studies have showed that approximately one-third of patients with IPMN are associated with invasive carcinoma, so precise basement membrane micro analysis is an imperative. Accordingly to their histological characteristics there are intestinal, pancreatobiliary, oncocytic and gastric subtype of IPMN with different immunohistochemical profiles. Intestinal-type IPMN is characterized by tall columnar cells with elongated nuclei and amphophilic cytoplasm and MUC2, MUC5AC, MUC4 and CDX-2 positivity. In contrast, pancreatobiliary subtype of IPMN is characterised by branched papillae with high grade intraepithelial neoplasms and MUC1 And MUC5AC immuno positivity. The third are oncocytic type, predominantly occurs in main duct and presented with a complex branched papillary structures covered by oncocytic cells mixed with goblet cells and mucin-containing cells. This type shows diffuse positivity for MUC5AC, MUC6 and focal positivity for MUC1 or MUC2. The gastric subtype is low grade lesions mainly found in branched ducts and characterised by papillae covered by foveolar glandular epithelium with MUC5AC and sometimes MUC6 positivity. The last and the most infrequent type of pre-cancerous pancreatic lesions are MCNs. The principle difference between IPMNs and MCNs is how they look under a microscope, and how they behave in the patient. These cystic lesions are almost solitary, typically located in the pancreatic body and tail. Grossly, this lesion can grow very large, it is usually septated and with fibrous pseudocapsule often with calcifications. Histologically, the epithelium og noninvasive MCN is consisted of columnar cells with varying degree of dysplasia (low grade, moderate and high grade dysplasia) and underlying ovarian-like stroma. Immunohistochemically, thode epithelial cells are EMA, CEA, MUC5AC, MUC2, cytokeratins 7, 8/18 and 19 positive, while the underlying ovarian-like stroma shows ER, PR, vimentin and SMA immune reactivity. Precancerous lesions of the pancreas are important changes whose visualization and detection in a significant number would reduce the incidence of pancreatic cancer and, consequently, the mortality of this highly aggressive neoplasm with an unfavorable therapy outcome.

Aim: To determine prognosic significance of RAS oncogene mutation detection in patients with metastatic colorectal carcinoma (mCRC). Introduction: CRC is still third most common cancer of both genders and second cause of death from malignancy in Western countries. In recent years, detecting RAS mutation in mCRC tumor tissue has became an imperative in selecting patients for monoclonal antibodies targeted therapy to Epidermal Growth Factor Receptor (EGFR). Nevertheless, there is no consensus regarding prognostic relevance of determining RAS status in patients with mCRC. Material and methods: Study included 116 patients with surgicaly resected CRC at Oncology Insitute of Vojvodina between January and December 2016. KRAS mutation detection was performed in formalin-fixed paraffin embeded tumor tissue samples processed by real-time chain polymerase reaction (real-time PCR) and applyng Cobas® KRAS Mutation Test and Cobas® 4800 System for detection of mutations in codons 12/13 and 61 of KRAS gene. Results: Average age in tested population was 65 years, with a male gender predominance (66.4%). Presence of KRAS mutation was found in 50.9% patients: 44.8% in codons 12/13, 4.3% in codon 61 and 1.7% in both codons 12/13 and 61. RAS mutated colorectal carcinomas (n=59) compared with RAS wildtype colorectal cancers, were significantly associated with male gender, moderately differentiated tumors, lymphovascular invasion and local nodal metastases. Conclusion: Our results show that, beside predictive, KRAS can also have prognostic significance regarding risk assesment for lymphovascular invasion and presence of local and distant metastases.

Introduction: GD is the commonest lysosomal storage disease worldwide. The majority of the patients have Type1 GD which is the non-neuronopathic form of disease. There are data of increased risk of cancer in GD patients, such as: multiple myeloma and other haematological malignancies, hepatocellular carcinoma and renal carcinoma. Factors of cancerogenesis in GD are accumulation of bioactive lipids, alternatively activated macrophages, immune dysregulation, genetic modifiers underlying the GD, splenectomy and enzyme replacement therapy. Extra-osseous soft tissue masses are described in GD patients, like localised deposition od Gaucher macrophages (Gaucheroma). To the best of our knowledge, no other case of extra-osseous soft tissue sarcoma in association with GD has been described in literature. To present very rare case of high grade leiomiosarcoma in association with Gaucher disease (GD). Case report: The case concerns 81 years old female with leucopenia and thrombocytopenia since year 2000. In 2014 she was diagnosed with undifferentiated pleomorphic sarcoma with prominent inflammation on her thigh, which was not completely surgically removed. She was diagnosed with leucopenia, thrombocytopenia and splenomegaly in 2014 on control examination. Bone marrow biopsy was performed and histologically and immunohistochemically was diagnosed GD. The diagnosis was confirmed by enzyme activity test. In 2018 revision of pathohistological finding of thigh tumour was performed. High grade leiomiosarcoma was diagnosed. She is alive and refuses any treatment. Conclusion: GD is rarely diagnosed in older age. All soft tissue masses in GD should be carefully examined because of increased risk of cancer in GD patients.

Aim: To investigate co-expression of ATRX and HIF-1α in kidney neoplasm in relation to its origin. Introduction: A heterogenous group of kidney tumors is believed to arise from a variety of specialized cells along the nephron – proximal tubules [Clear cell Renal Cell carcinoma (ccRCC) and papillary RCC (pRCC)] and collecting tubules [chromophobe RCC (chRCC) and oncocytoma]. ATP-dependent helicase (ATRX) is a chromatin remodeling protein involved in gene regulation and aberrant DNA methylation during cancerogenesis. Activation of hypoxia inducible factor (HIF-1α) is an early event in most RCC following inactivation of the VHL tumor suppressor gene. Material and Methods: A total of 46 kidney tumors (n=33 ccRCC, n=1 mRCC, n=4 pRCC, n=5 chRCC and n=3 oncocytomas) was immunohistochemically analyzed for ATRX and HIF-1α expression. Results: Diffuse and focal positivity of ATRX expression was found in 51.5% of ccRCC, while 54.5% had HIF-1α positivity. Co-expression of ATRX/HIF-1α was not related to nuclear grade and stage of ccRCC. Metastatic ccRCC had strong expression of both markers. pRCC type II showed weak ATRX/HIF-1α expression, while pRCC type I was negative for both markers. Interestingly, all analyzed oncocytomas and chromophobe RCC were negative for ATRX/HIF-1α. Conclusion: Our results suggest that signaling pathways have different patterns of activation/suppression of ATRX/HIF-1α in oncocytomas and chRCC compared to other RCC types. Downregulation or loss of ATRX/HIF-1α coexpression in benign tumors should be further investigated in order to determinate mechanisms of ATRX/ HIF-1α signaling transport renal neoplasm with different origin.

Aim: The aim of this study was to investigate the expression of Sox1 and Sox2 transcriptional factors in the subgranular zone (SGZ) of the hippocampus in 8 weeks old 5xFAD mice. Introduction: Transgenic 5xFAD mice represent a model of Alzheimer s disease (AD) characterized by an early deposition of amyloid plaques which disrupt the process of adult neurogenesis in the hippocampus. Certain transcriptional factors such as SoxB1 transcriptional factors are involved in the process of adult neurogenesis, but their roles in neurodegenerative disorders are not fully understood. Material and Methods: Transgenic mice of both genders and their respective non-transgenic controls (n=6 per group) were used in the study. Proliferating cells and immature neurons were detected by their immunohistochemical expression of Ki67 and doublecortin, while neuronal stem/precursor cells were identified by the expression of Sox1 and Sox2 proteins. Immunohistochemistry and counting were performed on hippocampal paraffin sections. Results: Immunohistochemical analysis showed that 5xFAD mice in the SGZ of the hippocampus have significantly lower numbers of Sox1 immunoreactive cells, while Sox2 immunoreactive cells were lower only in female 5xFAD mice. Furthermore, we have detected a decrease in the number of newly formed neurons in male transgenic mice, while the number of proliferating cells was unchanged when compared to non-transgenic controls. Conclusion: The results of our study show that early changes in the neurogenesis in 5xFAD model occur despite the preserved proliferative potential in the SGZ. Our results clearly indicate the importance of SoxB1 transcriptional factors in the early phases of AD.