Boban Stanojevic

Intraductal papilloma of ectopic breast tissue in axillary lymph node of a patient with a previous intraductal papilloma of ipsilateral breast: a case report and review of the literature

The presence of ectopic breast tissue in axillary lymph nodes (ALN) is a benign condition that must be differentiated from primary or metastatic carcinoma. Here we report a patient who underwent excision of enlarged ALN 10 years after she had received surgical treatment of ipsilateral breast for an intracystic intraductal papilloma (IDP). Histological examination of the removed ALN revealed that the proliferative lesion consisted of papillary and tubular structures lined by luminal cuboidal cells and a distinct outer layer of myoepithelial cells resembling IDP of the breast. Immunostaining with a set of immunohistochemical markers including AE/AE3, alpha-smooth muscle actin and p63 in combination with estrogen and progesterone receptors confirmed the diagnosis of ectopic IDP.This case shows that even though benign proliferative change in ectopic breast tissue is an extremely rare phenomenon, this possibility should be taken into account for correct diagnosis.

Unilateral follicular variant of papillary thyroid carcinoma with unique KRAS mutation in struma ovarii in bilateral ovarian teratoma: a rare case report

BackgroundStruma ovarii (SO) is a rare form of ovarian mature teratoma in which thyroid tissue is the predominant element. Because of its rarity, the differential diagnosis between benign and malignant SO has not been clearly defined. It is believed that malignant transformation of SO has similar molecular features with and its prognosis corresponds to that of malignant tumors originating in the thyroid.Case presentationWe report 35-year-old woman with bilateral ovarian cysts incidentally detected by ultrasound during the first trimester of pregnancy. Four months after delivery of a healthy child without complication she was admitted to the hospital for acute abdominal pain. Laparoscopic left adnexectomy was performed initially in a regional hospital; right cystectomy was done later in a specialized clinic. Intraoperative frozen section and a final pathology revealed that the cyst from the left ovary was composed of mature teratomatous elements, normal thyroid tissue (>50%) and a non-encapsulated focus of follicular variant of papillary thyroid carcinoma (PTC).Normal and cancerous thyroid tissues were tested for BRAF and RAS mutations by direct sequencing, and for RET/PTC rearrangements by RT-PCR/Southern blotting. A KRAS codon 12 mutation, the GGT → GTT transversion, corresponding to the Gly → Val amino acid change was identified in the absence of other genetic alterations commonly found in PTC.ConclusionTo the best of our knowledge, this is the first time this mutation is described in a papillary thyroid carcinoma arising in struma in the ovarii. This finding provides further evidence that even rare mutations specific for PTC may occur in such tumors. Molecular testing may be a useful adjunct to common differential diagnostic methods of thyroid malignancy in SO.

Molecular characterization and phylogenetic analysis of full-genome HBV subgenotype D3 sequences from Serbia

Hepatitis B virus (HBV) is classified into 8 genotypes with distinct geographical distribution. Genotype D (HBV/D) has the widest distribution area and is comprised of 7 subgenotypes. Subgenotypes D1, D2 and D3 appear worldwide, while D4-D7 have a more restricted distribution. Within the Mediterranean area, HBV/D and subgenotype D3 are the most prevalent. The purpose of this study was to characterize the full genome of Serbian HBV/D3 isolates by comparison and phylogenetic analysis with HBV/D3 sequences (66 samples) found in GeneBank/DDBJ databases from different parts of the world. Isolates were obtained from three patients diagnosed with chronic hepatitis B (HBsAg+). All three isolates have two very rare nucleotide substitutions, A929T and T150A, which indicate the same ancestor. Phylogenetic analysis of HBV/D3 genome sequences throughout the world follows an ethno-geographical origin of isolates with rare exceptions, which could be explained by human travelling and migration. The geographically close but ethnically different Serbian and Italian isolates clustered in the same subnode, and on a common branch with strains from Northern Canada. To test the apparently close HBV phylogenetic relationship between completely separated patients from Serbia and Northern Canada we analyzed in depth a 440 bp region of the HBsAg from Canadian (n=73) and Serbian (n=70) isolates. The constructed parsimony tree revealed that strains from Serbia and Northern Canada fell along the same branch which indicates independent evolution within regions of each country. Considering that HBsAg sequence has limited variability for phylogenetic analyses, our hypothesis needs further confirmation with more HBV complete genome sequences.

Significance of p53-binding protein 1 (53BP1) expression in thyroid papillary microcarcinoma: association with BRAFV600E mutation status.

In a previous report, we proposed that analysis of 53BP1 expression by immunofluorescence could be a useful tool in estimating the level of genomic instability (GIN), as well as the malignant potential, of thyroid tumours. In an attempt to clarify the value of 53BP1 expression as a new molecular marker for the aggressiveness of thyroid papillary microcarcinoma (PMC), we assessed the association between the type of 53BP1 expression and clinicopathological features such as tumour size, extrathyroidal invasion, lymph node metastasis and BRAFV600E mutation of PMC.

Radiation-Associated Small Cell Neuroendocrine Carcinoma of the Thyroid: A Case Report with Molecular Analyses

BACKGROUND Neuroendocrine tumor (NET) of the thyroid other than medullary carcinoma is extremely rare. We describe here a case of calcitonin-negative small cell neuroendocrine carcinoma (SCNEC), which occurred in a thyroid gland that had previously been irradiated at high dose (60 Gy) for pharyngeal cancer, with molecular analyses for follicular cell origin. PATIENT FINDINGS The tumor cells were small with fine chromatin, inconspicuous nucleoli, and inapparent cytoplasm, and showed neuroendocrine architectures such as palisading, rosettes, and trabeculae. Mitotic figures were numerous exceeding 10 mitoses per 10 high-power fields. The tumor cells invaded into several vessels and metastasized to regional lymph nodes. Immunohistochemically, the tumor cells were strongly positive for neuroendocrine markers and thyroglobulin (Tg), a marker of thyroid follicular cells but negative for calcitonin and carcinoembryonic antigen (CEA). Expression of Tg and thyrotropin receptor (TSHR) were confirmed by quantitative real-time polymerase chain reaction (RT-PCR). Ki-67 labeling index was more than 70% in the tumor cells. Taken together, the tumor was diagnosed as SCNEC of the thyroid. Genetic analyses also revealed microsatellite abnormalities of the phosphatase and tensin homolog (PTEN) gene, suggesting that functional loss of PTEN contributes to carcinogenesis. CONCLUSIONS This is the first report describing a SCNEC of the thyroid with molecular analyses that provide evidence for a follicular epithelial origin.

A case-control study of papillary thyroid cancer in children and adolescents.

Thyroid carcinomas in children and adolescents are rare tumors and the most common among them is papillary thyroid cancer (PTC). Its etiology is still under research and has not been clearly defined thus far, especially in young individuals. The aim of this case–control study was to determine potential risk factors for the development of PTC in children and adolescents. This type of study has not been carried out previously in this age group. A case–control study was carried out during a 15-year period, between 1995 and 2009. The case group included 75 patients with PTC younger than 20 years of age, with the youngest patient being 6.5 years old; 45 patients were female and 30 were male. The control group included the same number of participants, and the cases were individually matched by sex, age, and place of residence. Conditional univariate and multivariate logistic regression methods were applied in data analysis. According to univariate logistic regression analysis, PTC in children and adolescents was significantly related to the following factors: family history of thyroid cancer, family history of residence in an endemic-goiter area, family history of benign thyroid disease, and family history of nonthyroid malignant tumors. According to the multivariate logistic regression method, PTC in children and adolescents was independently related to a family history of thyroid cancer (odds ratio=4.5, 95% confidence interval=1.2–19.8) and a family history of nonthyroid malignant tumors (odds ratio=3.8, 95% confidence interval=1.4–8.7). In conclusion, all of the factors associated with the development of PTC in children and adolescents were related to their family history.

Low VHL mRNA Expression is Associated with More Aggressive Tumor Features of Papillary Thyroid Carcinoma

Alterations of the von Hippel–Lindau (VHL) tumor suppressor gene can cause different hereditary tumors associated with VHL syndrome, but the potential role of the VHL gene in papillary thyroid carcinoma (PTC) has not been characterized. This study set out to investigate the relationship of VHL expression level with clinicopathological features of PTC in an ethnically and geographically homogenous group of 264 patients from Serbia, for the first time. Multivariate logistic regression analysis showed a strong correlation between low level of VHL expression and advanced clinical stage (OR = 5.78, 95% CI 3.17–10.53, P<0.0001), classical papillary morphology of the tumor (OR = 2.92, 95% CI 1.33–6.44, P = 0.008) and multifocality (OR = 1.96, 95% CI 1.06–3.62, P = 0.031). In disease-free survival analysis, low VHL expression had marginal significance (P = 0.0502 by the log-rank test) but did not appear to be an independent predictor of the risk for chance of faster recurrence in a proportion hazards model. No somatic mutations or evidence of VHL downregulation via promoter hypermethylation in PTC were found. The results indicate that the decrease of VHL expression associates with tumor progression but the mechanism of downregulation remains to be elucidated.

Concurrent quantitation of the A and D genotypes of hepatitis B virus

Hepatitis B virus (HBV) infection is a global health problem associated with severe liver disorders. Viral load and HBV genotype affect the clinical outcome, guide antiviral therapy and provide long term prognosis for HBV infected patients. Various types of detection and quantitation assays are currently in use with a different effectiveness. The aim of this study was to develop a method that would provide simultaneous identification and quantitation of genotypes A and D in a single-tube reaction. Sera from infected patients were analyzed by a TaqMan based real time PCR. Optimized reagents were used for HBV DNA quantitation while the genotypes A and D were quantified separately by our design of the assay. Multiplex real time PCR was achieved and was specific for HBV genotypes A and D within a single-tube reaction. Simulation of mixed virus populations was identified reproducibly in vitro. Quantitation of these individual genotypes was exceptionally reliable, so much so that the sum of individual genotypes was equal to the total viral load determined in a separate reaction. Therefore, a straightforward, conceptually simple and reliable approach to issues involving HBV genotypes A and D is submitted. Identity and exact titer of these genotypes in the Caucasian population can now be determined easily.

Sequence variant in the intron 10 of the RET oncogene in a patient with microfollicular thyroid carcinoma with medullar differentiation: implications for newly generated chi-like sequence.

Sequence alterations in the RET proto-oncogene are becoming increasingly important to clinical assessment of the malignant disease of the thyroid. A spectrum of mutations is necessary to establish comprehensive phenotype to genotype relationship relevant to diagnosis and therapy of thyroid malignancies. We aimed to append to the increasing database of these oncogenic lesions and, therefore, analyzed DNA from tumor tissue and constitutive DNA from a patient with thyroid carcinoma. Mutational screening and sequence characterization of the RET proto-oncogene was performed to include part of the intronic sequences. We report a germline sequence variant in DNA from the patient diagnosed with microfollicular thyroid carcinoma. The carcinoma presented not as fully developed medullar carcinoma (MTC) but as microfollicular carcinoma with tendency to evolve into MTC. We characterized the sequence variant located in the intron 10 of the RET oncogene as an A to G substitution denoted IVS10 + 4G. The described sequence alteration generates a chi-like sequence surrounded by several chi-like sequences with recombinational potential. Such alteration may be involved in the pathogenesis of the microfollicular carcinoma via genome destabilization through homologous recombination in the process of tumor progression. This result further substantiates the importance of the database correlating specific sequence variations in the RET gene with distinct disease phenotypes.