Of note, the development of Noonan syndrome, Costello syndrome, and neurofibromatosis type 1 are RASopathies, associated with mutations in the RAS cell signaling pathway. ERMS caused by genetically inherited mutations is cannot be morphologically distinguished from spontaneously acquired ERMS. Diagnosis
Rhabdomyosarcoma is diagnosed through the presence of embryonic myogenesis, or skeletal muscle formation, which can be identified through morphological examination as well as assays containing myogenic markers. Immunohistochemical assays use protein expression to determine the fusion status of the growth, differentiating fusion-negative rhabdomyosarcoma from fusion-positive  rhabdomyosarcoma. In the recent years, there has been a shift to use molecular classification over histological classification as histology alone does not predict the fusion type of rhabdomyosarcoma. The performance of molecular genetic tests as well as matching the genotypic result to the clinical presentation are necessary to confirm the diagnosis of rhabdomyosarcoma as well as identify a subtype. Immunochemistry
Fusion-status is determined through the expression of certain proteins that indicate muscle differentiation, or immunomarkers, although the specific assay panel used for diagnosis depends on the tumor morphology. These immunomarkers include desmin, muscle-specific actin, Myogenin, and MyoD1, the latter two being transcription factors that are involved in muscle differentiation. Embryonal rhabdomyosarcoma can be classified by its lack of PAX3–FOXO1 or PAX7–FOXO1 gene fusions, but approximately 20% of alveolar rhabdomyosarcomas are also determined to be fusion-negative. However, it is suggested that these "fusion-negative" ARMS may be a misclassification of embryonal rhabdomyosarcomas with predominantly dense morphology. The World Health Organization recommends considering "fusion-negative" ARMS as a "primitive form of ERMS".
Idiopathic pneumonia syndrome is a set of pneumonia-like symptoms that occur with no sign of infection in the lung. Idiopathic pneumonia syndrome is a serious condition that can occur after a stem cell transplant. It occurs between 2.2 and 15 percent of hematopoietic stem cell transplants. The incubation period ranges between 4 and 106 days, but mostly is about 22 days from transplant. Symptoms
The symptoms are like pneumonia, and include fever, chills, coughing, and breathing problems. Lack of oxygen may also occur. Risk factors
Risk factors for IPS can be old age, graft vs host disease, multi organ failure, and multiple organ failure. Diagnosis
Treatment
Treatment is only supportive, with steroids showing no effect. The need for mechanical ventilation is indicative of a poor prognosis. Steroids are often used, though often without effect. References

Idiopathic pneumonia syndrome entry in the public domain NCI Dictionary of Cancer Terms This article incorporates public domain material from the U.S. National Cancer Institute document: "Dictionary of Cancer Terms".