Once keratinocytes begin to grow uncontrollably, they have the potential to become cancerous and produce squamous cell carcinoma. The lesion caused by SCC is often asymptomatic
Ulcer or reddish skin plaque that is slow growing
Intermittent bleeding from the tumor, especially on the lip
The clinical appearance is highly variable
Usually the tumor presents as an ulcerated lesion with hard, raised edges
The tumor may be in the form of a hard plaque or a papule, often with an opalescent quality, with tiny blood vessels
The tumor can lie below the level of the surrounding skin, and eventually ulcerates and invades the underlying tissue
The tumor commonly presents on sun-exposed areas (e.g. back of the hand, scalp, lip, and superior surface of pinna)
On the lip, the tumor forms a small ulcer, which fails to heal and bleeds intermittently
Evidence of chronic skin photodamage, as in multiple actinic keratoses (solar keratoses)
The tumor grows relatively slowly

Spread
Unlike basal-cell carcinoma (BCC), squamous cell carcinoma (SCC) has a higher risk of metastasis. Risk of metastasis is higher clinically in SCC arising in scars, on the lower lips or mucosa, and occurring in immunosuppressed and solid organ transplant patients. Risk of metastasis is also higher in SCC that are >2 cm in diameter, growth into the fat layer and along nerves, thickness >6mm. Causes
Squamous cell carcinoma is the second-most common cancer of the skin (after basal-cell carcinoma but more common than melanoma). It usually occurs in areas exposed to the sun.
In addition, trauma to extra-pelvic organs is common. Pelvic fractures are often associated with severe hemorrhage due to the extensive blood supply to the region. The veins of the presacral pelvic plexus are particularly vulnerable. Greater than 85 percent of bleeding due to pelvic fractures is venous or from the open surfaces of the bone. Diagnosis
If a person is fully awake and has no pain in the pelvis, medical imaging of the pelvis is not needed. Classification
Pelvic fractures are most commonly described using one of two classification systems. The different forces on the pelvis result in different fractures. Sometimes they are determined based on stability or instability. Tile classification
The Tile classification system is based on the integrity of the posterior sacroiliac complex.In type A injuries, the sacroiliac complex is intact. The pelvic ring has a stable fracture that can be managed nonoperatively. Type B injuries are caused by either external or internal rotational forces resulting in partial disruption of the posterior sacroiliac complex. These are often unstable. Type C injuries are characterized by complete disruption of the posterior sacroiliac complex and are both rotationally and vertically unstable. These injuries are the result of great force, usually from a motor vehicle crash, fall from a height or severe compression. Young-Burgess classification
The Young-Burgess classification system is based on mechanism of injury: anteroposterior compression type I, II and III, lateral
compression types I, II and III, and vertical shear, or a combination of forces.