Chorioangioma, or chorangioma, is a benign tumor of placenta. It is a hamartoma-like growth in the placenta consisting of blood vessels, and is seen in approximately 0.5 to 1% pregnancies. It is mostly diagnosed ultrasonically in the second trimester of pregnancy. Large chorioangiomas are known to cause complications in pregnancy, while the smaller ones are asymptomatic. Presentation
Most chorangiomas are not clinically significant, i.e. they do not have an adverse effect on placental function. Complications
Large (greater than 4 or 5 cm.) or multiple chorioangiomas may lead to complication. The complications are polyhydramnios, preterm labour, hemolytic anemia, fetal cardiomegaly, fetal thrombocytopenia, intrauterine growth retardation, preeclampsia, abruption of placenta and congenital anomalies. Pathogenesis
The origin of chorioangioma is from primitive chorionic mesenchyme. It develops when the blood vessels and stroma undergo rapid proliferation independent of the surrounding tissue. Based on histological features, chorioangioma is classified by Marchetti into three types:
Cellular type : This type is immature and contains mostly cellular elements packed compactly. Angiomatous (vascular) type : This is the most common type of choriocarcinoma. It is distinguished by the presence of numerous small blood vessels. Degenerative type : This is the mature type with degenerative changes.Each type is believed to represent a phase of tumor development. Chorioangioma has no malignant potential. Diagnosis
Most chorioangiomas are asymptomatic. They are generally picked up in second trimester scan. Chorioangioma is seen as a hypo- or hyperechoic circumscribed mass that is distinct from the placenta at gray-scale US examination. Large lesions may contain fibrous septa.
Polyonychia also known as supernumerary nails is a condition in which two or more nails grow in the same finger or toe. Signs and symptoms
The signs/symptoms of polyonychia are very easy to detect: two or more nails growing on the same finger or toe. The nails can either be separate, small nails (micronychia) or one wide, almost complete nail, the digit affected could also be wider than normal

Causes
Polyonychia is generally caused by a congenital duplication of the distal phalange of the affected digit(s), this can be caused by congenital factors (sporadic without a genetic link) or by genetic factors (sporadic or familial with genetic link). It can also be caused by polysyndactyly, which is characterized as one normal digit being connected/webbed (syndactyly) to an extra digit (polydactyly). Polyonychia can also be acquired, such as after an accident that affected the nail bed causing it to split. This type of polyonychia is just referred to as "post-traumatic split nail" Polyonychias syndromic causes include:

Isolated congenital onychodysplasiaPolyonychias non-syndromic causes include:

Polyphalangism (more specifically of the distal phalange)
Polysyndactyly

See also
Polydactyly
Syndactyly
Polysyndactyly


== References ==