Osteochondromas
Osteochondromas are benign tumors located on the surface of bone near growth plates. These tumors also often in the hands and feet, primarily affecting the digits of fingers and toes. These tumors tend to subside after 10-20 years of life. These tumors can become painful if they pressure sensitive tissue or nerves. Metachondromatosis is differentiated from hereditary multiple osteochondromas by the location of the location of Osteochondromas tumors as well as the lack of bone-shortening. Abnormality of epiphysis morphology
The epiphysis is the rounded end part of bone. The structure of the epiphysis can be abnormal in metachondromatosis. Abnormality of the metaphysis
The metaphysis is wide portion of a long bone, and also has abnormal structure in the disease. Avascular necrosis
Avascular necrosis is the death of bone due to a decreased blood supply. Bone pain
People with metachondromatosis often experience bone pain due to abnormal bone shapes. Cranial nerve paralysis
Cranial nerve paralysis can affect the functions associated with the cranial nerve. Genetics
Metachondromatosis is inherited in an autosomal dominant manner, needing only one copy of the defective gene to cause the disorder. The cause of the disorder has been linked to an 11 base pair deletion in exon four of the PTPN11 gene  (12q24.13). This deletion causes a frameshift, resulting in a nonsense mutation with a premature stop codon. This causes severe truncation and loss of function in the gene’s protein product, tyrosine phosphatase SHP-2.
A Spigelian is the type of ventral hernia where aponeurotic fascia pushes through a hole in the junction of the linea semilunaris and the arcuate line creating a bulge. It appears in the abdomen lower quadrant between an area of dense fibrous tissue and abdominal wall muscles causing a (Spigelian aponeurosis).It is the protuberance, of omentum, adipose tissue, or bowel in that weak space between the abdominal wall muscles, that ultimately pushes the intestines or superficial fatty tissue through a hole causing a defect. As a result, it creates the movement of an organ or a loop of intestine in the weakened body space that it is not supposed to be in. It is at this separation (aponeurosis) in the ventral abdominal region, that herniation most commonly occurs. Spigelian hernias are rare compared to other types of hernias because they do not develop under abdominal layers of fat but between fascia tissue that connects to muscle. The Spigelian hernia is generally smaller in diameter, typically measuring 1–2 cm., and the risk of tissue becoming strangulated is high. Signs and symptoms
Individuals typically present with either intermittent pain (coming and going), a lump, or mass all which are classic signs of a bowel obstruction. The patient may have a protuberance when standing in an upright position although discomfort can sometimes be confused by its anatomical region for a peptic ulceration. The bulge may be painful when the patient stretches but then goes away when they are lying down in a resting position.