Based upon our results, there is a different biological profile between right- and left-sided colonic tumors.

Nasopharyngeal lymphoepithelioma is an undifferentiated carcinoma in a dominated lymphoplasma-histiocyte stroma. Lymphoepithelioma-like carcinoma of the breast is the mammary counterpart of the lymphoepithelioma of the nasopharynx and is characterised by proliferation of poorly differentiated malignant cells within a prominent lymphoid infiltrate. It is a very rare primary carcinoma of the breast first reported in 1994 by Kumar and Kumar. Fewer than 40 cases have been reported in the English literature. In this manuscript a case of lymphoepithelioma-like carcinoma of the breast in a 57-year-old patient is reported along with a literature review on this rare entity.

ABSTRACT. KRAS and BRAF mutations are well-recognized molecular alterations during colorectal carcinogenesis, but there is little agreement on their effect on tumor characteristics. Therefore, we aimed to evaluate the distribution of the most common KRAS and BRAF mutations in Greek patients with colorectal cancer and their possible associations with clinical histopathological parameters. In this study, 322 and 188 colorectal carcinomas were used for the mutation analysis of KRAS (exon 2) and BRAF (exon 15) genes, respectively. The mutational status of both genes was evaluated by polymerase chain reaction and sequencing analysis. Although the overall frequency of KRAS mutations (36.6%) seemed to be similar to those reported for other populations, the rate of point mutations at codon 13 was significantly lower (12%) in Greek patients with colorectal cancer and associated with male gender (P < 0.05). Tumors with G>T codon 12 transversions and G>C transitions showed more frequent lymph 16793-16802 (2015) node metastasis (P < 0.05, P < 0.005, respectively). The rate of KRAS mutations gradually decreased with increasing histological grade (P < 0.05), as opposed to BRAF mutations, which were strongly associated with poorly differentiated tumors (P < 0.005). Additionally, we found that the histological features of preexisting adenoma were associated with the absence of BRAF mutations, in contrast to KRAS (P < 0.05). Our data suggested that there seems to be a correlation between morphological criteria and discrete genetic pathways in colorectal carcinogenesis. Moreover, ethnic or geographic factors may have an impact on genetic background of colorectal carcinomas, and specific types of KRAS mutations may influence the metastatic potential of colorectal tumors.

Introduction. Sarcomas of the breast are rare and hemangiopericytoma (HPC) of the breast is even rarer. Case Report. We report a case of a 43-year-old woman who presented with a 4 cm mass in her right breast. Her family history was positive for breast cancer. A fine needle aspiration indicated a malignant vascular tumor. An excision biopsy and frozen section analysis confirmed the presence of an encapsulated mesenchymal tumor. Its morphology and immunohistochemical marker profile were characteristic for a malignant hemangiopericytoma. Thus, she underwent a tumor excision without an axilla sampling. Approximately one year after the surgery the patient is well without local recurrence or metastasis disease to be observed. We also reviewed the literature and discuss the treatment options, characteristics, and immunophenotype of HPC. Conclusions. The accurate diagnosis of HPC depends on the appropriate histological and immunohistochemical examination. Surgical resection is the treatment of choice and due to scarcity of cases and unpredictable biological behavior of these tumors long term follow-up may be warranted.

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