Tumors from blood and lymph vessels

Benign tumors from blood vessels

1. Hemangioma is a tumor from blood vessels. There are several types of hemangioma:

a) capillary which develops in the skin, mucous membranes, gastrointestinal tract, liver, more often in children. It looks like cyanotic node of capillaries, branching with a narrow lumen;

b) venous: vascular bands with smooth muscles, resembles veins;

c) cavity hemangioma in the liver, skin, bones, muscles, gastrointestinal tract, brain;

d) benign hemangiopericytoma in the skin, intramuscular spaces of the extremities.

2. Glomus tumor (glomus angioma). More often develops in hands and feet (fingers and toes). There are vessels with endothelium, surrounded by muffles of epithelioid (glomus) cells, rich in nerves it is usually painful.

Malignant tumors from blood vessels Angiosarcoma which may be:

a) malignant hemangioendothelioma;

b) malignant hemangiopericytoma: highly malignant, early metastases (skin, liver, muscles).

Benign tumors from lymph vessels

Lymphangioma: growth of lymphatic vessels in different direction with formation of a node or enlargement of the organ. If lymphangioma develops in the tongue, it is termed macroglossia, if lymphangioma develops in the lip it is termed macrocheilia. Microscopically it looks like cavities filled with lymph. Malignant tumors from lymph vessels Lymphangiosarcoma. This appears as a result of chronic lymphatic stasis.

Tumors from synovial tissue

1. Benign synovioma develops in the tendons and tendon sheath. It contains a lot of stroma with hyalinosis, and a little number of vessels. There may occur xanthomic cells and clefts.

2. Synovial sarcoma (malignant synovioma) develops in the large joints. It has polymorphic structure. Some tumors have polymorphic cells and pseudoepithelial gland formations with cysts, the other have fibroblastoid atypical cells and collagen fibers, structures resembling tendons.

Tumors of mesothelial tissue

1. Benign mesothelioma resembles a dense node in serous membrane (pleura), its structure is similar to fibroma (fibroid mesothelioma).

2. Malignant mesothelioma (peritoneum, pleura, pericardium) microscopically looks like atypical large cells with vacuolized cytoplasm. Malignant mesothelioma may has tubular and papillary structures. Mesothelioma with tubular and papillary structures is called epithelial mesothelioma.

Bone tumors

Benign

1. Osteoma develops as a rule in spongy and tubular bones, skull. 2 types of osteoma are known: a) spongy osteoma, b) compact osteoma.

This benign tumor almost exclusively involves the skull and facial bones; the frontal sinus is the most common location. Males are affected more often than females, the lesion can occur at any age. Although osteoma is predominantly a solitary lesion, multiple osteomas can occur in association with intestinal polyposis and soft tissue tumors. The tumor of normal dense and mature bone originates from the periosteum. There is little evidence of osteoblastic activity.

2. Osteoid osteoma is common in young persons, mostly males. Macroscopically, an osteoid osteoma appears as a small round or oval mass containing a central red-brown, friable area. Microscopically, the tumor appears as a maze of irregular bone trabeculae, fibrous tissue, and vessels. The center of the tumor is rich in osteoblasts, calcification, and multinucleate giant cells.

3. Benign osteoblastoma predominantly affects the vertebrae and long bones of young males in the first three decades of life. Macroscopically, the lesions vary in size from a few to several centimeters. Microscopically, osteoblasts proliferate and osteoid production increases. Osteoclasts and multinucleate giant cells may be very numerous, especially in areas of blood extravasation.

Malignant

1. Osteosarcoma (osteogenic sarcoma) from osteogenic tissue rich in atypical cells of osteoblastic type with a lot of mitoses, the bone is primitive. 2 types of osteosarcoma are known: a) osteoblastic type (bone formation), b) osteolytic type (bone destruction).

Osteosarcoma is a highly malignant bone tumor characterized by the production of osteoid and bone. Most osteosarcomas arise in the metaphyseal end of long bones (predominantly the femur, humerus, and tibia), but they can involve any bone, including the small bones of the hands, feet and face. Osteosarcoma is the most common primary malignant tumor of bone (next to multiple myeloma), accounting for approximately 16% of all bone malignancies. The disease predominantly affects young males between age 10 and 20.

Macroscopical appearance. The tumor appears as a large necrotic and hemorrhagic mass. The lesion usually ends in the epiphyseal cartilage and rarely extends into the nearby joint space.

Microscopic appearance. Three types of osteosarcomas have been differentiated according to their predominant histologic patterns: osteoblastic, fibroblastic and chondroblastic. The hallmark of the tumor is the presence of a malignant stroma that contains osteoid and bone. The stroma shows bizarre pleomorphic cells,with hyperchromatic, irregular nuclei and abundant mitoses. Multinucleate giant cells are seen most often near zones of necrosis and calcification. Malignant cartilage may be present in small foci or as a large proportion of the tumor.

2. Giant cell tumor of bone (osteoclastoma) is an uncommon malignant tumor characterized by multinucleate giant cells. It occurs predominantly in women over age 19 and peaks in the third decade of life. The lesion almost always is localized in the distal portion of the long bones (femur or humerus), and 50% of these tumors occur in the area of the knee. Occasionally, the tumor involves the skull, pelvis, or small bones of the hands and feet.

The tumor is believed to originate from the mesenchymal cells of connective tissue.

Macroscopically, the tumor characteristically appears as multiple hemorrhagic cystic cavities that destroy the adjacent bone and are enclosed by a thin shell of new bone formation.

Microscopically, a vascularized stroma composed of spindle cells that contain multinucleate giant cells intermixes with areas of hemorrhage, inflammation, and hemosiderin deposits. Mitoses are present.

Cartilage tumors

Benign

1. Chondroma derives from hyaline cartilage in the feet, spine, breastbone, pelvis. If tumor is located in the peripheral area of the bone it is termed exchondroma, if in the center area of the bone, enchondroma.

Oilier's disease (enchondromatosis) is a rare, nonhereditary disorder in which multiple chondromas are present in the metaphysis and diaphysis of various bones.

Maffucci's syndrome is a congenital disease characterized by dyschondroplasia and multiple hemangiomas in the skin and viscera.

This neoplasm is thought to originate from heterotropic cartilaginous cell; nests in the medullary cavities of bones. Macroscopically, the lesion appears as a confluent mass of bluish hyaline cartilage with a lobular configuration. Microscopically, the cartilage appears moderately cellular, with occasional binu-cleate cells. Mitoses are absent.

2. Osteochondroma is the most common benign tumor of bone affecting patients under age 21. The lesions may be single or multiple and predominantly involve the metaphysis of long bones. Macroscopically, the tumor may range in size from 1 to several centimeters and appears as a stalked protuberance, with a lobulated surface jutting from the affected bone. The

periosteum of the adjacent bone covers the lesion. Microscopically, the cartilaginous cells appear lined up, mimicking the orientation of cartilaginous cells in a normal epiphysis. No mitoses are present.

3. Benign chondroblastoma consists of chondro-blasts, interstitial substance, marked osteoclast reaction. Chondroblastoma is a rare cartilaginous tumor that almost always involves the epiphyseal portion of the long bones. The tumor predominantly affects males in the second decade of life. Macroscopically, the tumor is round or oval in shape, with areas of cystic degeneration and hemorrhage. Microscopically, proliferation ofchondroblasts is intermixed with varying amounts of fibrous stroma and chondroid material. Multinucleate giant cells and calcifications are present. Mitoses are virtually absent.

4. Chondromyxoid fibroma is most commonly located in the metaphysis of long bones but occasionally can involve the epiphysis. It primarily affects males in the first and second decades of life. Macroscopically, the tumor is a well-circumscribed, solid mass with a cartilaginous appearance. The cortex of the bone is expanded by the tumor, which is limited by the periosteum. Microscopically, a variety of fibrous, myxomatous, and chondroid elements are seen together with multinucleate giant cells and macrophages that contain hemosiderin. When the tumor forms lobules, a condensation of nuclei occurs beneath the rim of the compressed adjacent tissue.

Malignant

Chondrosarcoma is a malignant cartilaginous tumor. The most common locations are the spine, pelvic bones, and upper ends of the femur and humerus. The tumor may arise de novo (primary chondrosarcoma) or originate from a preexisting benign cartilaginous lesion (secondary chondrosarcoma). Chondrosarcomas comprise between 7% and 15% of all bone neoplasms. The tumor occurs in patients between age 30 and 60 and in men three times more often than in women.

Macroscopically, a chondrosarcoma appears as a lobulated white or gray mass that contains mucoid material and foci of calcification.

Microscopically, there are islands of immature or poorly developed cartilage in which anaplastic cells with two or more nuclei are present within the lacunar space.

The neoplasm is slow growing and can remain locally aggressive for years, with a high tendency to recur and implant in soft tissues. Hematogenous dissemination to the lungs, liver, and kidneys takes place over the years, with eventual death of the patient. The 10-year survival rate ranges from 50% to 60%.






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