Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients.

Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.

Multiple genetic lesions in solid tumors: relevance to diagnosis, prognosis, and molecular mechanisms.

In recent years, significant progress has been made in identifying characteristic chromosomal and molecular rearrangements associated with several solid tumors. Most solid tumors studied have been found to be characterized by recurrent chromosomal abnormalities that are specific to histologic types. We have studied primary specimens of malignant melanoma, gastrointestinal cancer, renal carcinoma, lung and ovarian cancer, by cytogenetic and molecular means, and we discuss the genetic alterations found. Brief descriptions of the potential clinical utility, and biological relevance changes in these disorders are also discussed.

[Association of mutations of K-RAS oncogene and deletions of 18Q with lymph node metastasis of colorectal cancer]. / Associazione di mutazioni dell'oncogene K-RAS e delezioni del 18Q con metastasi linfonodali nel cancro del colonretto.

Molecular characterization of gastrointestinal cancer has greatly helped the definition of the key steps of the malignant transformation process and made it the best understood among the malignant cancers. Genetic influences on prognosis may have important implications for the management of the disease and help to design patient-tailored therapy. In order to acquire additional knowledge on this issue we have commenced an institutional study with the aim to identify the most frequent molecular alterations and make a correlation with the conventional histopathological parameters.

[Assessment of the presence of mutations of the epidermal growth factor receptors in tumors of various histologies]. / Valutazione della presenza di mutazioni del recettore dell'epidermal growth factor in tumori di varia istologia.

Recent reports from US and Japan have established that mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (Egfr) occur in a subset of patients with lung cancer that respond to therapy with gefitinib, a TK inhibitor. To gain further insights into the role of Egfr in carcinogenesis of lung and tumors of diverse histology, that are currently under investigation with drugs of the same class, we have taken in examination a panel of tumors consisting in 110 pulmonary adenocarcinomas, 40 pulmonary squamous carcinomas, 40 gastric adenocarcinomas and 40 colorectal adenocarcinomas. The sequence analysis of exon 19 and 21 of the Egfr has allowed the identification of 10 cases exhibiting specific deletions in exon 19 and 1 case with point mutation in a conserved residue in exon 21. All Egfr mutations occur specifically in lung adenocarcinomas while tumors of different histology result unaffected. The rate of mutation affecting these other tumors is either very rare, involves different domains of the receptor or other tyrosine kinases. The molecular analysis of the Egfr gene can help identify patients that will benefit from gefitinib therapy.