Myobroma is a pediatric type of tumor. It may arise in one area or occur in multiple sites. It contains nodules of spindle cells that appear to be related to smooth muscle and less differentiated cells that are small, round, and basophilic. These are rare tumors and at times can be fatal depending on where they grow. Many of the constituent cells of this tumor are called myofibroblasts. Rare cases have been discovered in adults. Most tumors are discovered prior to a patient's second birthday and many are discovered at birth. Many of the tumors are multicentric and arise in many different body parts, though most patients are reported with single masses. The most common sites of involvement include the skin, subcutaneous tissue, and skeletal muscle of the head and the neck. Any site, however, may be involved including bones and other organs. Myofibromas may be familial in nature, inherited via an autosomal dominant pattern of inheritance. It is unknown if these are actually painful tumors, since thy occur primarily in infants. Some of these tumors have a purplish color that resemble a hematoma, whereas others present as white nodules. Most of these tumors are 1-5 cm in diameter, and the soft tissue tumors contain calcifications that are apparent on radiographs. The bony lesions are generally lytic or cystic-appearing in nature. The bones that may be involved include the skull, vertebrae, ribs, femur and tibia. Most tumors of the skin and soft tissues are cured by simple excision. Spontaneous resolution of these tumors has also been reported. Infants with multicentric lesions that involve the abdominal or visceral organs usually have symptoms relating to the distribtion of these tumors and may die of disease.