Differential diagnoses

Accidental or traumatic tumor or hemorrhagic tumor:

Benign lipoma, myoma, neurofibroma

Myositis (ossificans, inflammatory)

Inflammatory myofibrohistiocytosis (pseudosarcoma, pseudotumor of the bladder)

Other neoplasias:

Non-Hodgkin lymphoma (NHL)

Neuroblastoma

Ewing sarcoma

Langerhans cell histiocytosis (LCH)

12.1.2 Incidence

•In childhood, 7.5% of all neoplasias

•Annually, new diagnosis in 8–12 in one million children less than 16 years old

•Seventy percent of children are less than 10 years old at diagnosis

•Ratio of boys to girls, 1.4:1

12.2Rhabdomyosarcoma (RMS)

12.2.1 Incidence and Localization

•About 50% of all soft tissue malignomas

•Annually, new diagnosis in 4.3–5.3 in one million children less than 16 years old

•Sixty-seven percent of children are less than 10 years old at diagnosis

•Ratio of males to females equals 1.5:1

Age distribution