In all events, IMT is a rare tumor with a reported incidence in 2009 of 150–200 cases/year in the United States.IMT lesions typically consist of, and are defined by, myofibrolastic spindle cells, i.e. specialized cells that are longer than wide, have a microscopic appearance that merges the appearances of fibroblasts and smooth muscle cells (see myofibroblast), occur in normal as well as tumor tissues, and in normal tissues are commonly designated  fibroblasts. However, the lesions in some IMF cases are dominated by sheets of epithelioid cells (which may have rounded shapes) with only a minor component of spindle cells. Tumors with these characteristics  are regarded as a subtype of IMT termed epithelioid inflammatory myofibroblastic sarcoma (EIMS).The tumors in IMT and EIMS consistently contain pro-inflammatory white blood cells and in most cases tumor cells that express highly abnormal oncogenic (cancer-causing) fusion proteins such as those that contain the active portion of anaplastic lymphoma kinase (ALK). It is not clear whether this inflammation, the genetic abnormalities, or both contribute to the development of IMT but drugs blocking the activities of the fusion proteins made by these genetic abnormalities may be useful in treating the disease. Signs and symptoms
IMT was regarded as a tumor that occurs in children or young adults and presented in the lung, mesentery, greater omentum or, less commonly, heart, liver, spleen, pancreas, colon, small intestine, spermatic cord, prostate, uterus, eye orbit, peripheral or central nervous system nerves, brain meninges, spinal cord, or other sites.
Or or OR may refer to:

Arts and entertainment
Film and television
"O.R. ", a 1974 episode of M*A*S*H
Or (My Treasure), a 2004 movie from Israel (Or means "light" in Hebrew)

Music
Or (album), a 2002 album by Golden Boy with Miss Kittin
O*R, the original title of Olivia Rodrigos album Sour, 2021
"Or", a song by Israeli singer Chen Aharoni in Kdam Eurovision 2011
Or Records, a record label
Organized Rhyme, a Canadian hip-hop group featuring Tom Green

Businesses and organizations
Or (political party) (lit.