8825/1 Myofibroblastic tumor, NOS


Synonyms

Inflammatory myofibroblastic tumor

Definitions

Connective, subcutaneous and other soft tissues
ICD-O-3 topography code: C49

Inflammatory myofibroblastic tumour (IMT) is a multinodular intermediate fibrocytic neoplasm that arises from soft tissue or viscera. It is histologically characterized by the presence of spindle-shaped myofibroblasts and a chronic inflammatory infiltrate composed of eosinophils, lymphocytes, and plasma cells. IMT can arise at any location throughout the body, but most commonly affects lung, mesentery, and omentum. The tumours are circumscribed, lobulated solid masses; extrapulmonary tumours range in size between 1 and 17 cm (mean diameter: 6 cm).
IMT predominantly affects children and young adults, with a slight predilection for females. Principal treatment is surgical excision. Approximately 25% of extrapulmonary IMT recur; metastases develop rarely (<5%)1
 
Fletcher CDM, Unni KK, Mertens F (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of Soft Tissue and Bone.
3rd Edition
IARC Press: Lyon 2002



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Bronchus and lung
ICD-O-3 topography code: C34

A multinodular intermediate fibrocytic neoplasm that arises from soft tissue or viscera, in children and young adults. It is characterized by the presence of spindle-shaped myofibroblasts, and a chronic inflammatory infiltrate composed of eosinophils, lymphocytes, and plasma cells.



Breast
ICD-O-3 topography code: C50

A usually low-grade neoplasm composed of myofibroblastic spindle cells with prominent admixed inflammatory cells, usually plasma cells.






Stomach
ICD-O-3 topography code: C16

A multinodular intermediate fibrocytic neoplasm that arises from soft tissue or viscera, in children and young adults. It is characterized by the presence of spindle-shaped myofibroblasts, and a chronic inflammatory infiltrate composed of eosinophils, lymphocytes, and plasma cells
4
 
Bosman FT, Carneiro F, Hruban RH, Theise ND (Eds.)
WHO Classification of Tumours of the Digestive System.
4th Edition
International Agency for Research on Cancer: Lyon 2010



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Nasal cavity and Sinuses
ICD-O-3 topography code: C30-C31

A multinodular intermediate fibrocytic neoplasm that arises from soft tissue or viscera, in children and young adults. It is characterized by the presence of spindle-shaped myofibroblasts, and a chronic inflammatory infiltrate composed of eosinophils, lymphocytes, and plasma cells.



Hypopharynx, Larynx and Trachea
ICD-O-3 topography code: C13, C32, C33

A multinodular intermediate fibrocytic neoplasm that arises from soft tissue or viscera, in children and young adults. It is characterized by the presence of spindle-shaped myofibroblasts, and a chronic inflammatory infiltrate composed of eosinophils, lymphocytes, and plasma cells.