Congenital fibrosarcoma with a novel complex 3-way translocation t(12;15;19) and unusual histologic features

Fluorescence In situ Hybridization: Cell-Based Genetic Diagnostic and Research Applications

Fluorescence in situ hybridization (FISH) is a macromolecule recognition technology based on the complementary nature of DNA or DNA/RNA double strands. Selected DNA strands incorporated with fluorophore-coupled nucleotides can be used as probes to hybridize onto the complementary sequences in tested cells and tissues and then visualized through a fluorescence microscope or an imaging system. This technology was initially developed as a physical mapping tool to delineate genes within chromosomes. Its high analytical resolution to a single gene level and high sensitivity and specificity enabled an immediate application for genetic diagnosis of constitutional common aneuploidies, microdeletion/microduplication syndromes, and subtelomeric rearrangements. FISH tests using panels of gene-specific probes for somatic recurrent losses, gains, and translocations have been routinely applied for hematologic and solid tumors and are one of the fastest-growing areas in cancer diagnosis. FISH has also been used to detect infectious microbias and parasites like malaria in human blood cells. Recent advances in FISH technology involve various methods for improving probe labeling efficiency and the use of super resolution imaging systems for direct visualization of intra-nuclear chromosomal organization and profiling of RNA transcription in single cells. Cas9-mediated FISH (CASFISH) allowed in situ labeling of repetitive sequences and single-copy sequences without the disruption of nuclear genomic organization in fixed or living cells. Using oligopaint-FISH and super-resolution imaging enabled in situ visualization of chromosome haplotypes from differentially specified single-nucleotide polymorphism loci. Single molecule RNA FISH (smRNA-FISH) using combinatorial labeling or sequential barcoding by multiple round of hybridization were applied to measure mRNA expression of multiple genes within single cells. Research applications of these single molecule single cells DNA and RNA FISH techniques have visualized intra-nuclear genomic structure and sub-cellular transcriptional dynamics of many genes and revealed their functions in various biological processes.

Congenital (infantile) fibrosarcoma of the scalp: a case series and review of literature

INTRODUCTION

Congenital infantile fibrosarcoma (CIFS) is a soft tissue sarcoma of infants mainly involving lower extremities usually presenting during the first year of life. A subset of cases occur in the head and neck, but scalp involvement is exceptionally rare.

PATIENTS AND METHODS

We report clinicopathological features of three cases of CIFS involving the scalp diagnosed between 2011 and 2012.

RESULTS

The ages of the three patients at the time of diagnosis ranged from 12 to 90 days (mean 48 days). All were males and presented with scalp swelling at birth which grew rapidly in size. The tumor was located in the left temporal region in two cases and the right temporoparietal region in one case. On imaging, underlying bone involvement was noted in two cases. The mean size of the resected tumors was 8 cm. All cases exhibited a cellular tumor arranged in sheets of uniform oval to spindle cells, increased mitosis, and hemangiopericytoma-like vessels. All patients are alive after a mean follow-up of 39.6 months. Recurrence was seen in one case due to incomplete excision. No metastasis was seen in any of the cases.

CONCLUSION

CIFS of the scalp is rare and carries a good prognosis. Underlying bone erosion is rare but was noted seen in two of our cases. A male predominance was seen in our cases.

Molecular strategies for detecting chromosomal translocations in soft tissue tumors (review)

Approximately one third of soft tissue tumors are characterized by chromosomal aberrations, in particular, translocations and amplifications, which appear to be highly specific. The identification of fusion transcripts not only supports the diagnosis, but provides the basis for the development of novel therapeutic strategies aimed at blocking the aberrant activity of chimeric proteins. Molecular biology, and in particular, cytogenetic and qualitative and quantitative polymerase chain reaction technologies, allow with high efficiency and specificity, the determination of specific fusion transcripts resulting from chromosomal translocations, as well as the analysis of gene amplifications. In this review, various molecular techniques that allow the identification of translocations and consequent fusion transcripts generated are discussed in the broad spectrum of soft tissue tumors.

Fibroblastic and myofibroblastic tumors in children and adolescents

Fibroblastic and myofibroblastic tumors in children and adolescents are a relatively common group of soft tissue proliferations that range from reactive to hamartomatous to neoplastic, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic and immunohistochemical overlap, despite significant clinical, genetic, and prognostic differences. The fibromatoses are a major subgroup, and all types of fibromatoses can occur in the 1st 2 decades of life. Intermediate and malignant fibroblastic-myofibroblastic tumors are an important group that includes variants of fibrosarcoma and other tumors with recurrent cytogenetic or molecular genetic abnormalities and low metastatic potential. Pathologic examination is enhanced by adjunct techniques, such as immunohistochemistry, cytogenetics, and molecular genetics, although morphology provides the ultimate criteria for a specific diagnosis. This article reviews the clinicopathologic features of fibroblastic and myofibroblastic tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents, the use of diagnostic adjuncts, and differential diagnoses.

Right foot congenital infantile fibrosarcoma treated only with chemotherapy

Congenital infantile fibrosarcoma (CIF) is a rare tumor in childhood. The 5-year survival rate for CIFs is high and has been reported between 84% and 93%, but limb-amputation/disarticulation is still a major problem. We report the case of a male newborn with a mass in his right foot. X-ray and MRI revealed a mass destroying all tarsal, metatarsal, and phalangeal bones. The patient was treated only with VAC chemotherapy and is able to walk normally.