It is reported that in the United States, microcephaly occurs in 2 to 12 babies per 10,000 births. Signs and symptoms
There are a variety of symptoms that can occur in children. Infants with microcephaly are born with either a normal or reduced head size. Subsequently, the head fails to grow, while the face continues to develop at a normal rate, producing a child with a small head and a receding forehead, and a loose, often wrinkled scalp. As the child grows older, the smallness of the skull becomes more obvious, although the entire body also is often underweight and dwarfed.Severely impaired intellectual development is common, but disturbances in motor functions may not appear until later in life. Affected newborns generally have striking neurological defects and seizures. Development of motor functions and speech may be delayed. Hyperactivity and intellectual disability are common occurrences, although the degree of each varies. Convulsions may also occur. Motor ability varies, ranging from clumsiness in some to spastic quadriplegia in others. Causes
Microcephaly is a type of cephalic disorder.
A thymoma is a tumor originating from the epithelial cells of the thymus that is considered a rare malignancy. Thymomas are frequently associated with neuromuscular disorders such as  myasthenia gravis; thymoma is found in 20% of patients with myasthenia gravis. Once diagnosed, thymomas may be removed surgically. In the rare case of a malignant tumor, chemotherapy may be used. Signs and symptoms
A third of all people with a thymoma have symptoms caused by compression of the surrounding organs by an expansive mass. These problems may take the form of superior vena cava syndrome, dysphagia (difficulty swallowing), cough, or chest pain.One-third of patients have their tumors discovered because they have an associated autoimmune disorder. As mentioned earlier, the most common of those conditions is myasthenia gravis (MG); 10–15% of patients with MG have a thymoma and, conversely, 30–45% of patients with thymomas have MG. Additional associated autoimmune conditions include thymoma-associated multiorgan autoimmunity, pure red cell aplasia and Good syndrome (thymoma with combined immunodeficiency and hypogammaglobulinemia). Other reported disease associations are with acute pericarditis, agranulocytosis, alopecia areata, ulcerative colitis, Cushings disease, hemolytic anemia, limbic encephalopathy, myocarditis, nephrotic syndrome, panhypopituitarism, pernicious anemia, polymyositis, rheumatoid arthritis, sarcoidosis, scleroderma, sensorimotor radiculopathy, stiff person syndrome, systemic lupus erythematosus and thyroiditis.One-third to one-half of all persons with thymoma have no symptoms at all, and the mass is identified on a chest X-ray or CT/CAT scan performed for an unrelated problem. Pathology
Thymoma originates from the epithelial cell population in the thymus, and several microscopic subtypes are now recognized.