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: The aim of this study was to investigate the association of local tumor survivin expression and serum concentration with clinical and histopathological parameters in melanoma patients. Introduction: Survivin is a multifunctional protein abundantly expressed in tumors of various types, including melanoma. There are still sparse data regarding relationship of melanoma cell survivin expression with accepted histopathological characteristics as well as serum concentration. Material and Methods: The level of survivin expression was determined immunohistochemically in tumor tissue and with ELISA test in the serum of 84 melanoma patients with melanoma. Results: Survivin expression was significantly higher in the patients whose tumor had ulceration, higher mitotic index, higher Clark and Breslow stage, that made vascular invasion or spread through lymphatic vessels in primary tumor, and in the patients with metastatic disease. The patients with high survivin expression score had almost double shorter disease free interval DFI comparing to those with weak local survivin expression and a small number of survivin cells (9 - 7 vs 19 - 13 months, respectively). The degree of tumor infiltrating lymphocytes presence in tumor tissue was significantly inversely associated with serum survivin concentration. Conclusion: Conclusion Survivin expression in tumor tissue and its serum concetration significantly correlate with clinical and histopathological parameters. Serum levels could be important in initial follow-up as indicators of those patients that would have aggressive local tumor growth and spreading.

Aim: To highlight the widespread metastatic potential of the cutaneous melanoma, as well as its tendency for unusual presentation of metastatic disease. Introduction: Melanoma is an aggressive, highly malignant disease that is derived from melanocytes. The incidence of melanoma is significantly increasing. Melanoma has a strong tendency for metastasis. After primary excision of tumour, about 30% of all patients shall develop distant metastasis within first 5 years after tumour diagnosis. Case report: A 48-year-old female patient had undergone a hysterectomy because of myomatous uterus. After pathohistological examination metastasis of melanoma was diagnosed in one of multiple leimyoma. Diagnosis was confirmed with positive immunohistochemical staining with MART1 and S100 protein. Insight into the medical records, revealed that patient was diagnosed with superficially spreading melanoma (Clark IV, Breslow III) on skin above her left breast, as well as 2 regional tumour-involved lymph nodes (pT3aN2bM0), 2 years prior to this hysterectomy. Uterine leiomyoma was the first diagnosed distant metastasis of cutaneous melanoma. Diagnosis of stadium IV melanoma was established. Conclusion: Melanoma is a particularly aggressive disease with unpredictable evolution, so the occurrence of metastases in unusual and unexpected localizations, as is the distant benign tumour in the presented case, shall probably happen more often in the future.

Aim: The aim of this research is to analyze the profile of Ezh2 expression in superficial urothelial bladder cancer, to investigate its correlation with clinicopathological parameters, as well as to determine the prognostic significance of Ezh2. Introduction: Superficial urothelial bladder cancer, without invasion of muscle layer, is associated with frequent recurrence, and represents significant burden for health care system. Ezh2 is epigenetic regulator with a major role in urothelial oncogenesis. Clinical investigations of Ezh2 inhibitors in treatment of solid cancers have already given encouraging results. Materials and Methods: Tumor samples from 410 patients with superficial bladder cancer (172 pTa, 238 pT1), obtained by transurethral resection, were incorporated in tissue microarrays, and analyzed immunohistochemically to Ezh2 expression. Correlation analysis with clinicopathological parameters was performed using SPSS 18.0. Results: High nuclear expression was found in 33.4% tumors, and it was significantly more frequent in pT1 (46.6%), compared to pTa tumors (15.1%) (p<0.001). Ezh2 expression was associated with high histologic grade, presence of carcinoma in situ, and cancer specific death (p<0.001, respectively). In Kaplan-Mayer survival analysis high Ezh2 expression was significantly associated with poor prognosis and shorter patients survival (p<0.001). There was no significant correlation between Ezh2 and recurrence of the disease, and recurrence free interval (p<0.05). Conclusion: Immunohistochemical expression of transcription repressor Ezh2 in superficial urothelial bladder cancer indicates aggressive behavior of the tumor, and poor prognosis. Ezh2 could be used as pronostic marker in selection of the patients that might require more intense clinical treatment, and as potential target of anticancer therapy.

Aim: Case report for rare complication rectorrhagia induced by rectal lipoma incarcerated in the anus . Introduction: Colorectal lipomas are rare tumors that are commonly diagnosed in the right colon, accidentaly during colonoscopy. When the lipomas are larger then 2 cm, they cause pain, bleeding, obstruction, incarceration and torsion. Material and Methods: We present the case of 50-year old man who comes to emergency ambulance with abundant rectorrhagia and blood presented on underwear and thighs. It is noted prolapse of the soft structure through the anus which is reponated into the anus. Anoproctoscopy was performed, which determines that it is polyp of rectum, although it seemed to be incarcerated hemorrhoids, due to the fact that the patient has been suffering from hemorrhoids with bleeding for several years,which is treated conservatively. It was found that it was not hemorrhoids prolaps or bleeding from them. Flexibile rectoscopy was performed on the untreated gut. The polypoid structure on peduncle,was verified in the distal rectum,3,5 cm from the pectinate line. Polypoid formation was electroresected and sent for pathohistological examination. Results: The patient was well tolerated intervention. Resected specimen revealed sessile pseudopolypoid tumor,eroded mucosa , diameter 28x25x24 mm.Histopathology revealed submucosal lipoma . Eroded mucosa is accompanied by focuses microbloods. Microcircuits of fatty necrosis are visible inside the lipoma. Conclusion: Lipom of the rectum is rare entity which is accidentaly diagnosed during colonoscopy. Extremly rare, lipom causes bleeding, which we present here.

Aim: To present three cases and review literature of splenic myoid angioendothelioma (SMA) focusing on immunohistochemical features. Introduction: SMAs are very rare, mainly in middle-aged and elderly patients of both sexes and are characterized by a mixed proliferation of cord capillaries and myoid cells, distinguished from other splenic angioendotheliomas by additional myogenic/myofibroblast differentiation. Material and Methods: Three cases of SMA from the Department of Histopathology Registry of Clinical Centre of Serbia were detected during last 12 years (2006-2017) in one male and two female patients (42,5 ys average age). Histomorphological findings were revised by reviewing all serial HE sections, histochemical trichrome stains and immunohistochemical stainings for CD8, CD31, CD34, CD68, SMA, desmin and Ki-67. Results: All cases showed sharply demarcated non-encapsulated solitary tumors with diameters 42, 55 and 20 mm. Histologically there are dense network of capillary blood vessels intermingled with polygonal myoid stromal cells and at least focally expressed non-homogeneous cellularity of stromal and lymphoid cells with focal sclerosis. Neocapillaries show distinctive CD8- / CD31 / CD34 immunophenotype (differing them from splenic hamartomas) and characteristic mixture with myogenic elements (differing them from cord capillary hemangiomas): intense SMA (3/3), rare focal desmin (2/3) and focal CD68 (1/3) immunoexpression. Conclusion: SMA is underrecognized type of vascular neoplasia, which has a clinico-pathological differential diagnostic significance because it radiologically imitates splenic metastase. Cellular form of SMA must be distinguished from hamartoma, but also from hemangiopericytoma and well-differentiated angiosarcoma of the spleen

Aim: Purpose of this report is to present metastasis of lymph nodes melanoma with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) as an example of collision tumor of an uncommon synchronic occurrence in the lymph node. Introduction: Synchronic, composite tumors are rare and their simultaneous and synchronic occurence within the same tissue/organ is even more rare. CLL/SLL is an indolent, clonal disease of mature B-lymphocytes which occurs mostly with adults. After the treatment with chemotherapeutic agents the occurence of the secondary malignancies (melanoma,squamous-cell carcinoma). Material and Methods: We present a 77 year old male who, after right sided nephrectomy caused by clear-cell carcinoma was diagnosed with CLL/SLL with bone marrow and lymph node infiltration. After three years and chemotherapy, skin changes were excised which histomorphologically resembles melanoma. After the immunotherapy for melanoma, the enlarged lymph nodes were extripated from the neck and histomorphologically and immunohistochemically treated. Results: Histomorphologically, a diffused infiltration of small B-lymphocytes was found in the lymph node, with round nuclei, condensed chromatin, inconspicuous nucleoli, scant cytoplasm unique immunophenotype: CD20 ,PAX-5 ,CD5 ,CD23 ,Cyclin D1-,CD3-. A part of lymph node was infiltrated by epitheloid cells with immunohistochemic profile: S-100 ,Melan A ,HMB-45 . Histomorphological and immunohistochemical CLL/SLL with melanoma infiltration as an example of a collision tumor was proved. Conclusion: Lymphoproliferative neoplasms including CLL/SLL represent an risk of synchronous, metachronous development of secondary malignancies including melanoma itself and they can uncommonly present themselves as synchronic collision tumors within the same organ.

Aim and introduction: Pediatric nodal marginal zone lymphoma (NMZL) is a rare, but distinct subtype of NMZL with characteristic clinical presentation, pathohistological and molecular features, therapy and prognosis. Results: We report the case of a 15-year-old boy with no remarkable past history, presented with painless enlargement of left submandibular lymph node (LN) for three months. He was admitted to the University Children’s Hospital in Belgrade in May 2016. The cervical ultrasound demonstrated moderate left submandibular lymphadenopathy, but also mild enlargement of two right submandibular LNs (17x7mm, 14x7mm). Physical examination, chest radiography and abdominal ultrasound revealed no hepatosplenomegaly and lymphadenopathy elsewhere. The result of blood count test was normal. Biochemistry showed elevated uric acid 499 umol/l, AST 45U/l, ALT 98U/l, and sedimentation rate (65mm/h). Urea, creatinine, alkaline phosphatase, LDH and CRP were normal. The patient underwent left submandibular LN excisional biopsy. The size of the LN was 47x37x20mm. The histopathological examination revealed partial architectural effacement: follicular hyperplasia and nodular B-cell infiltration with features of progressive transformation of germinal centers (PTGC) in the form of fragmentation of follicles. A CD20 immunostain shows an abnormal expansion of the marginal zone with infiltration of interfollicular space. These B-cells were negative for CD3, CD5, CD23, EBV-LMP1, bcl-6, CD10, EMA, CD30, CD15, MUM-1, and positive for bcl-2 and IgD. A CD21/ CD23/ fascin immunostain showed an expanded and disrupted follicular dendritic cell meshwork. Ki-67 highlighted residual follicular polarisation and a low proliferation rate in the interfollicular areas. Based on these pathohistological findings it was concluded that LN likely represent reactive follicular hyperplasia with atypical marginal zone hyperplasia or possible PNMZL, with APSTRAKTI 95 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. recommendation of polymerase chain reaction (PCR) analysis of clonality. Additional IGH PCR analysis demonstrated biclonal heavy chain gene rearrangement. These findings were consistent with PNMZL. After consultation with members of International BFM study group for non-Hodgkin lymphomas, followup was recommended without any treatment. The patient has remained disease free for 22 months since diagnosis. Conclusion: We presented a rare case of PNMZL with morphological features of PTGC, but immunohistochemistry and additional PCR clonality analysis were crucial for final diagnosis. This case represents a diagnostic and therapeutic challenge because of their rarity in the pediatric population.

Strano telo u disajnim putevima predstavlja životno ugrožavajuće stanje i zahteva urgentnu evaluaciju i lečenje. Prepoznavanje kliničke slike gušenja, anestezija i uklanjanje stranog tela u dečijem uzrastu predstavljaju veliki izazov za dečijeg anesteziologa i otorinolaringologa. U slučaju organskih stranih tela iritacija, inflamacija i bubrenje mogu dodatno komplikovati situaciju. Najuži deo disajnih puteva u deteta je subglotis i rigidni bronhoskop iritira ovo područje što može uzrokovati postoperativnu opstrukciju disajnog puta. Prikazujemo slučaj 13 mesečnog deteta koje je aspiriralo strano telo u levi bronh, kliničku sliku, preoperativnu pripremu, tehniku anestezije, tok rigidne bronhoskopije, kao i probleme sa kojima smo se susretali do izlečenja deteta.

Adnexal tumors of the skin comprise heterogenous group with over 40 defined entities, classified by predominant differentiation into lesions with apocrine and eccrine, follicular, sebaceous, or multilineage differentiation. Some, but not all these entities are represented by benign and malignant counterparts. Their occurrence may be sporadic or as a part of inherited syndromes (e.g. Muir-Torre syndrome, Brooke-Spiegler Syndrome, or Cowden’s syndrome). Adnexal tumors may arise de novo or within hamartomatous lesions such as nevus sebaceous of Jadassohn. Adnexal carcinomas are very rare tumors (the incidence is less than 0.001%), with variable local recurrence, metastatic potential, and survival. Porocarcinoma, hidradenocarcinoma and sebaceous carcinoma (especially ocular type) are considered to have a poor prognosis, with the highest risk of local recurrence and distant metastases. Mortality of the patients with porocarcinoma is very high (65-80%) if regional or distant metastases are present. The treatment of malignant adnexal tumors is usually surgical or less frequently with radiation therapy. Patients with metastases are usually treated with chemotherapy, mostly with cytotoxic reagents, and rarely with estrogen receptor antagonists. The detailed knowledge of genetic features of adnexal tumors is still lacking. Most of the studies examined only few of the genes using low throughput techniques. Development of new generations of genome sequencing methods led to better understanding of tumors with apocrine and eccrine differentiation. For many of their subtypes, it is still unknown whether there are specific genetic changes, that could even be of diagnostic significance. Hotspot mutations in HRAS (p.G13X and p.Q61X) were found in a subset of eccrine poromas and porocarcinomas. These mutations were found in tumors with other lines of differentiation and suggesting overlapping genetical characteristics among adnexal tumors. Due to their similar histological features, cylindroma and spiradenoma are usually considered as phenotypic variations of the same entity. Their histological features can be mixed, in which case a diagnosis of spiradenocylindroma is made. In cylindroma, MYB is upregulated either by mutations in CYLD gene (syndromic cases) or due to a rearrangement of MYB gene (sporadic cases). Genetic characteristics of spiradenomas, including the status of CYLD and MYB genes, are largely unknown. It is still unclear if these two are both histological and genetical “relatives” and what is the level of heterogeneity among tumors arising sporadically or within syndromes. The presence of chromosomal rearrangements in adnexal tumors is also unexplored. TORC1-MAML2 and EWSR1-POU5F1 fusions were found in significant number of hidradenomas. Initially it was thought these fusions could be characteristic for clear cell variant of hidradenomas, but no true correlation with histology was found. Molecular alterations that differ between benign and malignant counterparts and could enable targeted therapy of adnexal carcinomas are unknown. Mutations in TP53, often UV-associated, are frequent in malignant tumors with eccrine and apocrine differentiation and can drive malignant transformation in such tumors. Porocarcinomas and ABSTRACTS 96 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. hidradenocarcinomas harbor various molecular alterations affecting PI3K-AKT or MAPK pathways that could enable targeted therapy in the future. Actionable mutations in EGFR were not found in carcinomas with eccrine and apocrine differentiation thus far. Her2 amplifications are rarely found, mostly in hidradenocarcinomas, but its therapeutic potential has only been utilized only once.16,25 Mutations of PTCH1 and TCF7L1 in hidradenocarcinomas could also enable the treatment with the inhibitors of Hedgehog and WNT/Hippo signaling pathways. It seems that current knowledge gained from genomic studies of adnexal tumors is only a scratch on the surface. In addition, there is no data on epigenetic characteristics or transcriptome of adnexal skin tumors. Taken altogether, further and detailed investigation of genome, epigenome and transcriptome of adnexal tumors is necessary. Such integrated knowledge could explain mechanisms of their development, malignant alteration and progression, so the treatment of patients with metastatic adnexal carcinomas could be changed toward targeted therapy.