Frequency of low-level and high-level mosaicism in sporadic retinoblastoma: genotype-phenotype relationships.

Somatic mutational mosaicism is a common feature of monogenic genetic disorders, particularly in diseases such as retinoblastoma, with high rates of de novo mutations. The detection and quantification of mosaicism is particularly relevant in these diseases, since it has important implications for genetic counseling, patient management, and probably also on disease onset and progression. In order to assess the rate of somatic mosaicism (high- and low-level mosaicism) in sporadic retinoblastoma patients, we analyzed a cohort of 153 patients with sporadic retinoblastoma using ultra deep next-generation sequencing.

Expression of developing neural transcription factors in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH).

DIPNECH is characterized by neuroendocrine cell hyperplasia, tumorlets, and eventually carcinoid tumors. Although it is regarded by some authors as a preneoplastic condition, this issue is controversial. New pathologic criteria have recently been proposed for the diagnosis of DIPNECH, and a subgroup of carcinoid tumors expressing developing neural transcription factors (DNTFs), with clinicopathologic features similar to those of DIPNECH, has been recognized.

Molecular study of signaling-pathway genes in experimental rat thyroid carcinoma.

Introduction: A study was conducted on histological patterns and biomolecular changes in Goitrogen-induced experimental rat thyroid tumors. The link between the histological types observed and N-ras, B-raf, and PI3KCA gene mutations widely reported in human thyroid cancers was explored.

Material And Methods: An analysis was done on paraffin-embedded tumor tissue sections from Wistar rats receiving 1% potassium perchlorate (KClO(4)) added to the ad libitum drinking-water supply over an 18-month period.

Molecular findings of nasopharyngeal carcinoma in a European population.

Objective: To explore biomolecular characteristics of a group of patients with nasopharyngeal carcinoma from European (Spanish) hospitals, addressing the pathogenesis of the tumor and the response to treatment.

Study Design: Cyclin D1 and p16 expression were evaluated immunohistochemically in 33 tissue samples of nasopharyngeal carcinoma. CCDN1 gene amplification and p16 gene deletion were studied by fluorescence in situ hybridization.

Gastrointestinal stromal tumors (GISTs): role of CD 117 and PDGFRA Golgi-like staining pattern in the recognition of mutational status.

Aims: to determine whether potential correlations between CD117 and PDGFRA might serve as an indication for targeted therapies.

Material And Methods: immunohistochemical expression of CD117 and PDGFRA was evaluated in 99 paraffin-embedded GISTs in conjunction with KIT and PDGFRA mutational status.

Results: CD117-positive staining was noted in 93 out of 99 cases.

Inmunohistochemical profile of solid cell nest of thyroid gland.

It is widely held that solid cell nests (SCN) of the thyroid are ultimobranchial body remnants. SCNs are composed of main cells and C cells. It has been suggested that main cells might be pluripotent cells contributing to the histogenesis of C cells and follicular cells, as well as to the formation of certain thyroid tumors.