What is myofibroblastoma?

summary

Inflammatory myofibroblastoma (IMF) was defined by who in 2002 as "a mesenchymal tumor composed of differentiated myofibroblastic spindle cells, often accompanied by a large number of plasma cells and / or lymphocytes". They include plasma cell granuloma, histiocytoma, fibroxanthoma, inflammatory myofibroblastic histiocytosis, myxoid hamartoma, pseudolymphoma, inflammatory fibrosarcoma and inflammatory pseudotumor, especially the latter.

What is myofibroblastoma?

It occurs in children and adolescents, with an average age of 10 years old. It can also occur in adults, and it is slightly more common in women. It occurs in soft tissue and internal organs, and can be located in all parts of the body. The most common parts are lung, omentum and mesentery. The greater omentum is the most common site except the lung, accounting for 43% of the total. Other sites include soft tissue, mediastinum, gastrointestinal tract, pancreas, genitalia, oral cavity, breast, nerve, bone and central nervous system.

Depending on the location of the disease, the onset of the disease is more insidious. The clinical symptoms are mostly caused by the mass itself and its surrounding organs. In addition, there may be fever, weight loss, pain, anemia, thrombocytosis, and accelerated erythrocyte sedimentation rate. The clinical symptoms are similar to those of malignant tumors, but they are lack of specificity. The symptoms and signs often disappear after tumor resection.

There are various manifestations in different parts, and lack of specific signs. 1. IMT occurred in the lung as a single lesion, mostly in the peripheral pleural. 2. The central type has a clear boundary. It can be accompanied by atelectasis and various calcifications can be seen inside. It is more common in children. 3. The interface between the tumor and the lung is fuzzy. There are long and thick burrs or spinous processes, which are different from the short hairy spines of lung cancer; The edge of one side of the lesion was straight and showed knife like change, which was called "straight sign". It may be caused by fibrotic traction at the edge of the lesion, or it may be related to the formation of the lesion along the edge of the lung lobe or segment; It may be caused by pleural adhesion and fibrous tissue hyperplasia around the lesion; These signs can be used as the basis for differentiating benign and malignant lung tumors.

matters needing attention

Some people think that IMT is also called inflammatory pseudotumor, which is wrong. IMT is a rare borderline (occasionally metastatic) tumor with inflammatory background and myofibroblastic proliferation. A few of them have recurrence tendency and malignant potential. Therefore, IMT and inflammatory pseudotumor are not the same disease. IMT includes inflammatory pseudotumor, besides inflammatory pseudotumor, plasma cell granuloma, histiocytoma, fibroxanthoma, inflammatory myofibroblastic histiocytosis, etc.