Soft Tissues: Inflammatory myofibroblastic tumor

2003-08-01   Jean-Loup Huret  

1.Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France

Clinics and Pathology

Epidemiology

found in children and young adults

Clinics

occurs in the soft tissue and viscera; the tumour is localized in lungs, mesentery, retroperitoneum, and pelvis.

Pathology

spindle cell proliferation with myofibroblastic differenciation with a collagen stroma and an inflammatory infiltrate of lymphocytes, eosinophils, and plasma cells

Treatment

surgical excision

Prognosis

This tumour has an indeterminate or low malignant potential; tumour related deaths (occuring in less than 10% of cases) are due to local invasion, not to distant metastases

Cytogenetics

Cytogenetics morphological

So far, t(1;2)(q25;p23), t(2;2)(p23;q13), t(2;11)(p23;p15), t(2;17)(p23;q23), and t(2;19)(p23;p13.1) have been described; the t(1;2)(q25;p23) with TPM3 involvement would be the most frequent.

Genetics

Note

about one 50 to 60 % of the cases present with a 2p23 rearrangement involving the gene ALK; this subset of tumours should have a different genetic background, and may have a different behaviour, in terms of epidemiology (younger age?), prognosis ...

Genes Involved and Proteins

Note

these translocations involve ALK in 2p23, and either TPM3 in 1q25, CLTC in 17q23, or TPM4 in 19p13

Gene name

ALK (anaplastic lymphoma receptor tyrosine kinase)

Location

2p23.2

Protein description

1620 amino acids; 177 kDa; glycoprotein (200 kDa mature protein) ; membrane associated tyrosine kinase receptor

Gene name

TPM3 (tropomyosin 3)

Location

1q21.3

Protein description

284 amino acids, 33 kDa; coiled coil structure; role in Calcium dependant actin-myosin interaction

Gene name

RANBP2 (RAN binding protein 2)

Location

2q12.3

Protein description

3224 amino acids, 358 kDa; nuclear pore protein involved in nuclear export

Gene name

CARS (cysteinyj-tRNA synthetase)

Location

11p15.4

Gene name

CLTC (clathrin heavy polypeptide)

Location

17q23.1

Protein description

1675 amino acids, 191 kDa; mediate endocytosis of transmembrane receptors.

Gene name

TPM4 (tropomyosin)

Location

19p13.12

Protein description

248 amino acids, 29 kDa; coiled coil structure

Result of the chromosomal anomaly

Description

5 partner - 3 ALK

Description

N-term amino acids from the partner gene fused to the 562 C-term amino acids from ALK (i.e. the entire cytoplasmic portion of ALK with the tyrosine kinase domain); homodimerization of the fusion protein is known or suspected.

To be Noted

Note

ALK and some of the above ALK partners, or closely related genes, are found implicated both in anaplasic large cell lymphoma and in inflammatory myofibroblastic tumours; this is a new concept, that 2 different types of tumour may result from the same chromosomal/genes

Article Bibliography

Pubmed IDLast YearTitleAuthors

Citation

Jean-Loup Huret

Soft Tissues: Inflammatory myofibroblastic tumor

Atlas Genet Cytogenet Oncol Haematol. 2003-08-01

Online version: http://atlasgeneticsoncology.org/solid-tumor/5073/gene-fusions-explorer/favicon/meetings/haematological-explorer/

Historical Card

2001-08-01 Soft Tissues: Inflammatory myofibroblastic tumor by  Jean-Loup Huret 

Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France