Long bone ameloblastoma

Introduction to long bone ameloblastoma The long bone ameloblastoma (adamantinomaoflongbone) is a primary low-grade malignant tumor of the bone. Its histopathology is similar to the ameloblastoma of the jaw, which occurs in the backbone and metaphysis of the long bone, especially in the tibia. The disease is extremely rare and is a rare tumor after the nerve and fat-derived tumor of the bone. basic knowledge The proportion of illness: this disease is rare, the incidence rate is about 0.0001%-0.0003% Susceptible people: no specific people Mode of infection: non-infectious Complications: osteofibrosis

Causes of long bone ameloblastoma

(1) Causes of the disease

The cause is unknown.

(two) pathogenesis

Gross pathological features Long bones are eccentric, the tumor tissues with clear boundaries are mostly surrounded by cortical bone and periosteum, and the surrounding cortex is hyperplastic and hardened. The profile is grayish white, tough, and has a nodular structure. It can have cystic changes and hemorrhage, sometimes visible bone. And calcification, some cases can invade soft tissues.

The histological features of the tumors vary from case to case, and may vary from site to site. Weiss and Dorfman classify their main histological features into four forms:

1 Basal cell type: strip-like and nested cells are similar to basal cell carcinoma. These cells are prismatic in the center of the nest. The surrounding cells are cuboidal or cylindrical, arranged in a fence-like manner, and the reticulated fibers surround the cells. In the wild, there are few intercellular fibers in the nest, and the tissue structure is similar to the epithelium.

2 spindle cell type: similar to the previous one, except that there is no surrounding peg-like cell arrangement, sometimes the cells are arranged in a vortex, and the reticulated fibers surround the simple cells (characteristics of mesoderm tumors), which is similar to fibrosarcoma.

3 squamous cell type: most of the cell nests with squamous epithelial differentiation, the cells are round or polygonal, cytoplasmic eosinophilic, keratinized particles, cells stained positive with Keratin antibody,

4 adenoid structure type: the cell is covered with cracks of different sizes, some of the fissures contain red blood cells, other fissures are empty, the cells are covered, and they are cuboidal or cylindrical, resembling an adenoid structure, and the reticulated fibers surround the lumen. At the same time, it is also dispersed among the cells. All the aforementioned cell structures are surrounded by the fibrous matrix, and are easily distinguished based on these characteristics, but in the same lesion, there are many types of mixed types, and one is mainly composed of a substrate. Cell type is the most common, followed by prismatic cells and adenoid structures, and squamous cell types are rare.

Long bone ameloblastoma prevention

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Long bone ameloblastoma complications Complications, bone fibrosis

It can be associated with pathological fractures, and fibrous heterogeneous proliferation can coexist with this disease.

Symptoms of long bone ameloblastoma Common symptoms Joint pain Slow growth Muscle atrophy

The age of onset is 10 to 70 years old. The best age is 20 to 40 years old. It is rare before 10 years old. There are slightly more males. Mori reports 156 cases, males account for 55.8%, and women account for 44.2%.

The best part of the hair is the humeral shaft. This part occurs in almost 90% of the cases, but it has been reported in the ulna, humerus, femur, tibia and fibula. Most of the disease is single, occasionally multiple, and there are reports (Donald) Fibrous abnormalities coexist.

Symptoms and signs: slow tumor growth, long course of disease, mostly in years, mainly mild pain or local progressive swelling, the tumor rarely grows into a large mass, lesion destruction can cause pathological fracture, tumor quality at the time of examination Hard, uneven surface, muscle atrophy, adjacent joints can affect joint function.

Examination of long bone ameloblastoma

No relevant laboratory tests.

There is a typical X-ray manifestation. In the humerus, the tumor surface is limited to the anterior cortical bone, producing one or several long and shallow crater-shaped X-ray translucent areas, and there is a sub-periosteal reaction bone thin shell, between the lesions. There are 1 ~ 2cm of normal bone tissue, forming a unique soapy defect, often associated with pathological fractures.

Diagnosis and differentiation of long bone ameloblastoma

The localized bone defect in front of the tibia is like a volcanic crater. There is mild pain. If the course is longer, the disease should be considered. The diagnosis depends on pathological examination.

It should be distinguished from non-osteogenic fibroids, cartilage myxoid fibroma, vascular endothelial cell tumor, fibrosarcoma and metastatic cancer.

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