Typically patients present with progressive pain, often long standing and/or bony swelling and restricted range of movement in affected limb 3,12. The latter is most often the case in bones with little overlying soft tissues (e.g. short tubular bones of the hands and feet).

Most chondromyxoid fibromas are located in the metaphyseal region of long bones (60%), and may extend to the epiphyseal line and even rarely abut the articular surface 3,12. They are almost never just epiphyseal 3. The classical site is the upper 1/3rd of tibia ( which accounts for 25% of all cases) with the small tubular bones of the foot, the distal femur and pelvis being other relatively common locations 12.

Rarely occur in the skull or skull base.

The majority of cases occur in the second and third decades, with approximately 75% of cases occurring before the age of 30 years 1,12-15. There is no recognised gender predilection. Examples have however been seen in patients up to the age of 75 years. In some series there is a male predilection 12 whilst in others no such distribution is found 2

Malignant transformation to squamous cell carcinoma may occur, but is unusual.

Swelling is the most common presenting complaint; however, OKCs may be asymptomatic and found incidentally on dental X-rays.

A myxoid liposarcoma is a malignant adipose tissue neoplasm of myxoid appearance histologically.

Myxoid liposarcomas are the second most common type of liposarcoma, representing 30–40% of all liposarcomas in the limbs; occurring most commonly in the legs, particularly the thigh, followed by the buttocks, retroperitoneum, trunk, ankle, proximal limb girdle, head and neck, and wrist. They occur in the intermuscular fascial planes or deep-seated areas. They present as a large, slow-growing, painless mass.

They are associated with a fusion between DDIT3 or "CHOP" (at 12q13.1-q13.2) and FUS or "TLS" (at 16p11.2) or EWS (at 22q12.2).

The specific translocation of FUS-DDIT3 is t(12;16)(q13;p11).

An odontogenic tumor is a neoplasm of the cells or tissues that initiate odontogenic processes.

Examples include:

- Adenomatoid odontogenic tumor

- Ameloblastoma, a type of odontogenic tumor involving ameloblasts

- Calcifying epithelial odontogenic tumor

- Keratocystic odontogenic tumor

- Odontogenic myxoma

- Odontoma

Trichilemmoma (also known as "tricholemmoma") is a benign cutaneous neoplasm that shows differentiation toward cells of the outer root sheath. The lesion is often seen in the face and neck region. Multifocal occurrence is associated with Cowden syndrome, in which hamartomatous intestinal polyposis is seen in conjunction with multiple tricholemmoma lesions.

Nominally, the disease consists of multiple enchondromas which usually develop in childhood. The growth of these enchondromas usually stops after skeletal maturation. The affected extremity is shortened (asymmetric dwarfism) and sometimes bowed due to epiphyseal fusion anomalies. Persons with Ollier disease are prone to breaking bones and normally have swollen, aching limbs.

Patients present with a slow-growing, painless, solitary mass, usually of the subcutaneous tissues. It is much less frequently noted in the intramuscular tissue. It is not uncommon for symptoms to be present for years.

Benign neoplasm with "BROWN FAT" is noted.

On radiographs, streaks of low density are seen projecting through the diaphyses into the epiphyses of the long bones, due to ectopic cartilage deposits. With age, the cartilage may calcify in the typical "snowflake" pattern.

Brown tumours consist of fibrous tissue, woven bone and supporting vasculature, but no matrix. The osteoclasts consume the trabecular bone that osteoblasts lay down and this front of reparative bone deposition followed by additional resorption can expand beyond the usual shape of the bone, involving the periosteum thus causing bone pain. The characteristic brown coloration results from hemosiderin deposition into the osteolytic cysts. Hemosiderin deposition is not a distinctive feature of brown tumors; it may also be seen in giant cell tumors of the bone.

Brown tumors may be rarely associated with ectopic parathyroid adenomas or end stage renal osteodystrophy.

This lesion has been called a fetal lipoma, lipoma of embryonic fat or a lipoma of immature fat.

The most common symptom is mild to severe pain that is gradually progressive in the affected region and may be initially attributed to a minor injury or sports-related injury. Pain may be present for several weeks, months, or years. Other symptoms in order of most common to least commonly observed include swelling, a limp (when affected bone is in the lower extremity), joint stiffness, and a soft tissue mass.

Physical findings include localized tenderness and a decreased range of motion in the involved bone and nearby joint, muscle atrophy, a palpable mass, soft tissue swelling, and joint effusion in the affected area. Less commonly, pathological fractures can be found, especially in cases involving the foot. In cases involving the temporal bone, tinnitus, dizziness, and hearing loss have been reported.

In a publication by Turcotte et al. it was found that the average duration of symptoms for patients with chondroblastoma was about 20 months, ranging from 5 weeks to 16 years.

Pleomorphic adenoma is a common benign salivary gland neoplasm characterised by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components, having a malignant potentiality. It is the most common type of salivary gland tumor and the most common tumor of the parotid gland. It derives its name from the architectural Pleomorphism (variable appearance) seen by light microscopy. It is also known as "Mixed tumor, salivary gland type", which describes its pleomorphic appearance as opposed to its dual origin from epithelial and myoepithelial elements.

Benign and borderline variants of this neoplasm are rare, and most cases are malignant.

These tumors may have a worse prognosis than serous tumors.

A chondroma is a benign cartilaginous tumor, which is encapsulated with a lobular growing pattern.

Tumor cells (chondrocytes, cartilaginous cells) resemble normal cells and produce the cartilaginous matrix (amorphous, basophilic material).

Characteristic features of this tumor include the vascular axes within the tumor, which make the distinction with normal hyaline cartilage.

Based upon location, a chondroma can be described as an enchondroma or ecchondroma.

- enchondroma - tumor grows within the bone and expands it.

- ecchondroma - grows outward from the bone and this is rare.

Treatment

- best left alone

- if it causes fractures (enchondroma) or is unsightly it should be removed by curettage and the defect filled with bone graft.

The tumor is usually solitary and presents as a slow growing, painless, firm single nodular mass. Isolated nodules are generally outgrowths of the main nodule rather than a multinodular presentation. It is usually mobile unless found in the palate and can cause atrophy of the mandibular ramus when located in the parotid gland. When found in the parotid tail, it may present as an eversion of the ear lobe. Though it is classified as a benign tumor, pleomorphic adenomas have the capacity to grow to large proportions and may undergo malignant transformation, to form carcinoma ex-pleomorphic adenoma, a risk that increases with time (9.5% chance to convert into malignancy in 15 years). Although it is "benign" the tumor is aneuploid, it can recur after resection, it invades normal adjacent tissue and distant metastases have been reported after long (+10 years) time intervals.

Trichoepithelioma is a neoplasm of the adnexa of the skin. Its appearance is similar to basal cell carcinoma.

One form has been mapped to chromosome 9p21.

The brown tumor is a bone lesion that arises in settings of excess osteoclast activity, such as hyperparathyroidism. It is not a true neoplasm, as the term "tumor" suggests; however, it may mimic a true neoplasm. It most commonly affects the maxilla and mandible, though any bone may be affected. Brown tumours are radiolucent on x-ray.

An acanthoma is a skin neoplasm composed of squamous or epidermal cells. It is located in the prickle cell layer.

Types of acanthoma include pilar sheath acanthoma, a benign follicular tumor usually of the upper lip; clear cell acanthoma, a benign tumor found most frequently on the legs; and Degos acanthoma, often confused with but unrelated to Degos disease.

Children affected by pilocytic astrocytoma can present with different symptoms that might include failure to thrive (lack of appropriate weight gain/ weight loss), headache, nausea, vomiting, irritability, torticollis (tilt neck or wry neck) difficulty to coordinate movements and visual complaints (including nystagmus). The complaints may vary depending on the location and size of the neoplasm. The most common symptoms are associated with increased intracranial pressure due to the size of the neoplasm.

The treatment is simple excision and exclusion of a malignant neoplasm.

Typically, they are cystic neoplasms with polypoid masses that protrude into the cyst. On microscopic pathological examination, they are composed of cells with clear cytoplasm (that contains glycogen) and "hob nail" cells (from which the glycogen has been secreted). The pattern may be glandular, papillary or solid.

Chondroblastoma is a rare, benign, locally aggressive bone tumor that typically affects the epiphyses or apophyses of long bones. It is thought to arise from an outgrowth of immature cartilage cells (chondroblasts) from secondary ossification centers, originating from the epiphyseal plate or some remnant of it.

Chondroblastoma is very uncommon, accounting for only 1-2% of all bone tumors. It affects mostly children and young adults with most patients being in the second decade of life, or less than 20 years of age. Chondroblastoma shows a predilection towards the male sex, with a ratio of male to female patients of 2:1. The most commonly affected site is the femur, followed by the humerus and tibia. Less commonly affected sites include the talus and calcaneus of the foot and flat bones.

Carcinoma "in situ (CIS), also known as in situ" neoplasm, is a group of abnormal cells. While they are a form of neoplasm there is disagreement over whether CIS should be classified as cancer. This controversy also depends on the exact CIS in question (i.e. cervical, skin, breast). Some authors do not classify them as cancer, however, recognizing that they can potentially become cancer. Others classify certain types as a non-invasive form of cancer. The term "pre-cancer" has also been used.

These abnormal cells grow in their normal place, thus ""in situ"" (from Latin for "in its place"). For example, carcinoma "in situ" of the skin, also called Bowen's disease, is the accumulation of dysplastic epidermal cells within the epidermis only, that has failed to penetrate into the deeper dermis. For this reason, CIS will usually not form a tumor. Rather, the lesion is flat (in the skin, cervix, etc.) or follows the existing architecture of the organ (in the breast, lung, etc.). Exceptions include CIS of the colon (polyps), the bladder (preinvasive papillary cancer), or the breast (ductal carcinoma "in situ" or lobular carcinoma "in situ").

Many forms of CIS have a high probability of progression into cancer, and therefore removal may be recommended; however, progression of CIS is known to be highly variable and not all CIS becomes invasive cancer.

In the TNM classification, carcinoma "in situ" is reported as TisN0M0 (stage 0).