Muir-Torre syndrome (MTS) is defined as the association of a sebaceous tumor or keratoacanthoma and an extracutaneous neoplasm, mainly from the gastrointestinal or genitourinary tracts. MTS is related to hereditary non-polyposis colorectal cancer (HNPCC), a syndrome with germline mutations in the mismatch repair (MMR) gene(s), leading to microsatellite instability (MSI). In this study, using immunohistochemistry and a microsatellite instability assay, we analyzed the incidence of MMR gene abnormalities in 79 sebaceous lesions from 70 patients, 26 of whom also had an extracutaneous visceral neoplasm. We were unable to investigate the family histories of our patients regarding other tumors in order to assess which of our cases met the Amsterdam criteria. Defective MMR protein expression (MMR-) was found in 18/70 (25.7%) patients, with an identical distribution between those having an isolated skin tumor (11/44, 25.0%) and those with an extracutaneous cancer (7/26, 25.4%). In the sporadic group, MMR negative lesions were significantly more frequent in extrafacial areas (P = 0.03). High concordance was found between MMR expression in sebaceous lesions and the extracutaneous neoplasm in the same patient (20/23, 86.9%), as well as between MMR expression and microsatellite status (18/20, 90%). In conclusion, this study confirms the value of immunohistochemistry to identify MMR defective tumors. However, since only a minority of sebaceous neoplasms in patients who also have an extracutaneous cancer display MMR defects, these techniques are of limited value for the identification of "clinically defined" MTS.

This article reports the clinical and the histological features in a 7-year-old girl affected by common variable immunodeficiency (CVID) who developed multiple Epstein-Barr virus-associated tumors, represented by bilateral adrenal smooth muscle tumors (EBV-SMT) and multifocal diffuse large B-cell lymphoma. The EBV-SMTs showed features compatible with a benign or at least a low-malignant potential neoplasm. A peculiar feature observed in both EBV-SMTs was the occurrence of numerous lymphocytes intermingled with the spindle cells, which consisted of CD3+ CD5+ T-cells, with a predominant cytotoxic CD8+ component. Interestingly, EBV status differed in the neoplasms, since the EBV-SMTs were negative for LMP1 and positive for EBER, whereas the B-cell lymphoma expressed both EBV markers. Furthermore, EBV-LMP1 deletion was positive only in the EBV-SMTs, thus indicating that these tumors were the consequence of 2 distinct, EBV-dependent transformations. Similarly, lymphocyte clonality assay also showed different clonal bands in different sites (skin and nasal cavity), suggesting the development of intratumoral mutations. Finally, the authors review all 127 previously reported EBV-SMT, with discussion of their clinical and pathological features.

Neuroendocrine tumors of the digestive tract are rare entities characterized by significant phenotype differences and traditionally considered to originate from cells of the diffuse endocrine system of the pancreas and gut. Two major categories with significant phenotype and clinical behavior differences are identified as well-differentiated and poorly differentiated tumors. Investigation on the molecular basis of tumor development points to an important role for the multiple endocrine neoplasia syndrome type-1 (MEN1) gene because of its frequent abnormality observed both in well-differentiated and poorly differentiated tumors. Other genes are possibly involved, though the available data need support from studies on larger series of tumors.

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Although relatively rare, endocrine tumors of the digestive tract and pancreas have been widely investigated and represent a complex tumor entity. The two major categories of well-differentiated and poorly differentiated tumors show important phenotypic and clinical differences. In well-differentiated tumors the multiple endocrine neoplasia syndrome of Type 1 (MEN1) gene is frequently abnormal, though a complex multiple gene involvement is postulated for different tumor types. Poorly differentiated carcinomas show frequent p53 gene hyperexpression/defects, characterizing severe cell abnormality and possibly accounting for the malignancy of such carcinomas.

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The genetic study of two cases of tubulovillous adenoma associated with poorly differentiated endocrine carcinoma (PDEC) is reported. Aim of this work was to assess whether the exocrine and endocrine growths share a common genotype. The analysis entailed the search for allelic loss (LOH) or imbalances of polymorphic microsatellite markers at the corresponding chromosomal loci of the genes MEN-1 (11q13), p53 (17p13). Deleted in Colorectal Carcinoma (DCC) (18q21) and hMSH-2 (BAT26) (2p21-22). Additionally, the exons 5-8 of the p53 gene were sequenced in the two PDECs only. One of the two cases investigated showed LOH for 18q DCC markers in the tubulo-villous adenoma while a point mutation of the p53 gene was observed in the PDEC component. No genetic abnormality was observed in both adenoma and PDEC components of the other case. In the two cases p53 protein accumulation was observed in both PDEC and adenoma cells. These data indicate that only the p53 gene abnormality is shared by both colon cancer and PDEC in the two cases reported. The lack of other common genetic defect may suggest a different histogenesis for the two tumor types. The development of colon PDEC implies the defect of p53 gene.

Endometrial cancer (EC) represents the most frequently occuring gynecological tumor worldwide. The aim of the present study was to estimate the prognostic value of triple negative phenotype (TNP) in EC, and any associations with to pathological and clinical characteristics. The present study includes 220 cases of patients with EC who underwent to surgery at the Guglielmo da Saliceto Hospital of Piacenza (Italy) and the expressions of estrogen receptor (ER), progesterone receptor (PR) and oncoprotein c-erbB-2 (HER2) expression were examined. Pearson's Chi-square and Fisher's exact test were used to evaluate the association of TNP cases with variables associated with a worse prognosis. Progression-free survival (PFS) and overall survival (OS) were analyzed with Kaplan-Meier curves. A total of 26 patients (12%) had a TNP, and these cases had a higher percentage of high-risk histology, an advanced stage of disease at the time of diagnosis, with shorter PFS and OS when compared to non-TNP. The present study confirmed that TNP represents prognostic significance in EC.